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View Full Version : Anyone put a (newer) crate engine in '91 Prostar 190


davekro
07-21-2007, 02:40 PM
Fuel injection would be very nice too.

My '91 has 1600 hours and is still running well (re-build carb issues right now), but since I love the boat, I like the idea of putting a new crate engine (preferably EFI) one day.

1) I'm wondering what constraints there are for engine replacement in this boat that I might encounter?

2) Are the engine choices limited? If so, what would be a good choice?

3) Should I expect any issues to arise after a new engine?

I am not interested in MAJOR horsepower, but an upgraded to more current standards, would be nice. I do have a friend that bought an '89 PS 190 that the prev. owner had put an aluminum block sprint car motor into...
Way more power and head aches than I need for skiing! ;o)

Thanks, Dave
Discovery Bay, CA

bowtie355
07-21-2007, 06:43 PM
Love the LS1,2/6 and 7 generation engine line GM currently manufactures for the Corvette. It an all aluminum engine, very easy to build HP and holds up to the abuse but the major hurdle would be the water-cooled manifolds. I don't think there available yet. The exhaust ports on the LS heads are similar to a big block,where they are evenly separated apart. This engine would also drop around 200 to 300 lbs off the boat. I check out the 2007 Mastercraft and their still using the first generation small block with port injection.
http://www.vetteworksonline.com/engineconversions/43101b.jpg

TMCNo1
07-21-2007, 07:02 PM
Fuel injection would be very nice too.

My '91 has 1600 hours and is still running well (re-build carb issues right now), but since I love the boat, I like the idea of putting a new crate engine (preferably EFI) one day.

1) I'm wondering what constraints there are for engine replacement in this boat that I might encounter?

2) Are the engine choices limited? If so, what would be a good choice?

3) Should I expect any issues to arise after a new engine?

I am not interested in MAJOR horsepower, but an upgraded to more current standards, would be nice. I do have a friend that bought an '89 PS 190 that the prev. owner had put an aluminum block sprint car motor into...
Way more power and head aches than I need for skiing! ;o)

Thanks, Dave
Discovery Bay, CA

It would require a new gas tank, with electric fuel pump and all the computer stuff to make it run, as a start.

davekro
07-22-2007, 07:23 AM
Bowtie, I guess this is 'a general cool engine suggestion', but not one that is a drop in without major mods or additions.

TMCNo1, you bring to mind some additional thoughts...
I was thinking of a motor that did not require adding an expensive 'computer'. Does fuel injection by definition, need a computer? Or not necessarily? I had not even thought of needing to buy all new bolt on stuff that a long block needs (alternator, fuel pump, water manifolds, exhaust manifolds, et al !)
1)Maybe, more realistically, would I not be looking at a long block, but a whole new (marinized) engine assembly? I wonder what price range(s) that might be? (certainly way more than the $2,500 Chevy 350 crate motor I just had put into my work truck! ;o)

2) So, if I was previously (dreaming) of using all my old 'goes onto a long block' parts, I assume I'd need to stick to another 351. In this scenario, would I be limited to another '91 (or 92-93) carburated 351?

3) Or, would a newer fuel injected 351 engine assy work?

4) Or, I'm realistically looking at $7k- $10K+ (I have no frame of reference) for a complete new engine asssembly? My original idea had a $3k - $5k thought to it.

Dave

JimN
07-22-2007, 09:41 AM
Unless you want to try one of the old mechanical injection systems from the '50s, it'll need a computer. Remember, if it has sensors, they need to tell something what they're reading and whatever they tell needs to do something about the info.

If you want to buy a new motor and get more HP, you can buy carbed or injected- what you want to service and maintain will matter. If you know carbs but not injection, you're going to need someone to work on it if problems arise, or learn how to diagnose it yourself. You could also make rebuilding yours a winter project and bore it out, replace the intake, cam, replace freshen up the heads and other updates. If you can install it, you'll save quite a bit of money but it'll need alignment and tweaking once it's in. There are a lot of performance upgrades for a 351.

You could buy a reman motor and install it yourself. I used Jasper motors when I was working on boats and they worked well- good value and ran great. Not one was or had a problem.

Changing to a GM is pretty easy. The manifolds, shift/throttle linkage and cooling system are available through MC parts and if you buy a GM crate motor with injection, the computer comes mounted on a bracket- it wouldn't be hard to get it wired up. However, I have read the GM Performance Parts brochures and they specifically state that marine use kills the warranty. I would recommend calling to see if they have marine motors, but the 350 Ramjet would definitely get you going- 350 HP and 390 ft-lb of torque.

H20skeefreek
07-22-2007, 10:42 AM
WWW.SKIDIM.COM (http://www.SKIDIM.COM) has new 351 GT-40's that come with a computer for 6500. It will bolt right in place of a carbed 351.

davekro
07-22-2007, 11:52 AM
JimN, from the 50's... ooooh, I wanna a hemi (maybe that was th e60's ;o). I have no problem getting FI. I was not sure if the computer added a huge challenge. If it comes with and matched to the engine as the GT40 (below), that is fine with me.

H20skeefreek,
http://www.skidim.com/prodinfo.asp?number=GT40MPI
This looks good! Allready to go, complete with marinization et al.
LH Bobtail? I know Nauty is the only one that turns the 'wrong' way, but are our LH rotation? Bobtail??? Is that like the old expression: "It fell off a truck." (er,meaning it did not go the regular distributor supply chain... so to speak. ;o)

Skidim says: "Limited supply, only three left." Does that mean you can't get GT40's anymore after these (meaning not being made any more?) If so, what might be the 'new' easy drop in for all the old cab 351's? I do not nead a new more now, and hopefully not for seasons to come! I'm just trying to plan ahead.

Thanks, Dave


http://www.skidim.com/prodinfo.asp?number=GT40MPI

davekro
07-22-2007, 12:01 PM
Well the risers look like my Indmar 351... ;o)
Hey, the only boat I have seen the water pump mounted off to the side was on Nauties! Well they do use PCM... ;o)
Is the GT40 MPI, by definition a PCM, or did Indmar do them too.

Am I correct to assume, there would be no inherant preference for an Indmar vs. a PCM marinized engine? (other than the odd look I'd get with someone seeing PCM in that era of MC) Did MC ever use PCM?

Thanks, Dave

JimN
07-22-2007, 12:10 PM
3 left may mean just that. Ford got out of marine in about '94 and haven't made one since, although PCM bought everything they had, when they announced it.

Re: the ECM- matched to the motor is one thing but it needs to be matched to the boat, like MC does it to really be done right. Load means everything when it comes to calibrations.

"Bobtail" refers to the harness- think of dogs and having their tail trimmed, or "bobbed". Short harness that plugs into the boat's harness.

If you want to plan ahead, think in terms of having it rebuilt, unless you go and have a catastrophic engine failure.

davekro
07-22-2007, 01:30 PM
Jim N,

One reason my mind went to 'new', other than preferred reliability of a factory built engine, is that one head has a spider crack at the #1 spark plug hole. water does not visibly come from it, but there is a rust trail down the block from there. It makes me wonder if it might encroach on a water jacket inside the head one day, and cause major problems. But, to your rebuild point, this likely could be diagnosed during rebuild and replace head if an issue of concern.

Personally I have not torn a motor down and sent parts to machine shop for rebuild since my fist car (in high school), so I would not trust my skills for that task (even pulling in favors from knowing friends). Having had many reasons to question the attention to detail, or skill of many mechanics I have run into over my 50+ years... Well lets just say, factory rebuild 'feels' safer.

I suppose it is possible to ask around my area, friends and friends of friends for positive experience with rebuild shops. I would guess I might be looking at $2,000 - $3,000 (vs. $6,500 for new GT 40) for the rebuild, plus installation of maybe $2,000 +/-, if I farmed that part out too.

What do you think the (not to radical) mods one might make to this '91 351 might make, to boost HP somewhat? Ball park added costs?

Thanks for your help!
Dave

H20skeefreek
07-22-2007, 01:51 PM
I was chatting with the owner of PCM just yesterday. They have an entire warehouse full of these motors, as a matter of fact, they ship about 3 containers per year to ski boat manufacturers in Australia. I would imagine, since skidim and PCM are VERY closely related, that if they want more, they'll get more.

JimN
07-22-2007, 01:53 PM
If it's cracked, it's only a matter of time till something happens but OTOH, it's hard to even say what will or won't happen.

One route is to have it rebuilt by a local speed shop. They know all kinds of tricks and if they have a good reputation, should stand behind it. I went on a tour of Jasper's plant in Indiana and that was part of the reason the dealership started using theirs- they bore out all motors, toss a lot of the old parts due to wear and re-grind the cam. They're very thorough and when a motor is bought from them, they'll ask if it's for marine use, so they can supply the right one. They have a really good warranty on the marine versions, too.

If someone charges $2000 just to install your new motor, go somewhere else- it's not that hard and shouldn't take that long.

The usual mods will make it faster (more fun) - help it breathe better and it'll be quicker. Easttxskier and Brieod changed their manifolds and carbs, which made a definite improvement, possibly their cams, too. Roller rockers and lifters cut down on friction and add more HP/torque. Undersized pulleys can add a bit, too. Jeg's, Summit Racing and other speed sites are a good place to look for parts and advice.

bowtie355
07-22-2007, 02:31 PM
Bowtie, I guess this is 'a general cool engine suggestion', but not one that is a drop in without major mods or additions.

TMCNo1, you bring to mind some additional thoughts...
I was thinking of a motor that did not require adding an expensive 'computer'. Does fuel injection by definition, need a computer? Or not necessarily? I had not even thought of needing to buy all new bolt on stuff that a long block needs (alternator, fuel pump, water manifolds, exhaust manifolds, et al !)
1)Maybe, more realistically, would I not be looking at a long block, but a whole new (marinized) engine assembly? I wonder what price range(s) that might be? (certainly way more than the $2,500 Chevy 350 crate motor I just had put into my work truck! ;o)

2) So, if I was previously (dreaming) of using all my old 'goes onto a long block' parts, I assume I'd need to stick to another 351. In this scenario, would I be limited to another '91 (or 92-93) carburated 351?

3) Or, would a newer fuel injected 351 engine assy work?

4) Or, I'm realistically looking at $7k- $10K+ (I have no frame of reference) for a complete new engine asssembly? My original idea had a $3k - $5k thought to it.

Dave
I convert older vehicles over to modern fuel injection engines all the time, it's part of my business. You can use external high-pressure fuel pump instead of going with an in tank pump. GM already sells aftermarket PCM (computer) for hot rodders using crate LS power plants. Programming the PCM is not a big deal. The conversion would be easy except for the water-cooled manifolds. No one makes them for LS series small blocks. Fabricating engine mounts and tying into the transmission (velvet drive) would not be hard. V-drives would be even easier. I never said this would be cheap. If you had a shop do the work, it would be spendy. This is defiantly not a job for a 1st timer. It might not be practical, but would be fun modification.

Todays fuel injection engines are all computer controlled. There were a few mechincal unit built by rodchester in the 60's, but they didn't perform very well.

I don't think Ford ever built a fuel injected 351W. They did for the 351C and 460.

Currectly PCM and others already have Chevrolet Gen 1 small blocks with port injection, processor control set up available for sale.

To have someone convert your boat over to a fuel injected engine it would be over $10k.

davekro
07-22-2007, 02:32 PM
JimN, Thanks for the good advice. I will definitely reseach local speed shops when the time comes for a new engine in my '91 PS.

H20skeefreek,
"Ford got out of marine in about '94 and haven't made one since, although PCM bought everything they had, when they announced it." I wonder what effect 13+ years of being stored in a wharehouse has on these 'new in '94 engines? I would think that amount of time period, let alone in a widely fluctuating temperature environments (hot wharehouse) might be an issue?? But what do I know. ;o)

With 1600 hours on my '91 Indmar 351, it still runs great. I wonder what range of hours skiers are getting on inboards (in fresh water).

Dave

davekro
07-22-2007, 02:38 PM
Bowtie,
"To have someone convert your boat over to a fuel injected engine it would be over $10k."

Well then... hopefully, the answer to my question of: "# of expected hours for an inboard ski boat?". Is a BIG number! ;o)

Dave

bowtie355
07-22-2007, 04:57 PM
Bowtie,
"To have someone convert your boat over to a fuel injected engine it would be over $10k."

Well then... hopefully, the answer to my question of: "# of expected hours for an inboard ski boat?". Is a BIG number! ;o)

Dave

I would stick with the 351W. I'm not a Ford guy, but I know the 351W is a good dependable engine. It's no hot rod but you don't need that type of power plant with these boats. I plane on moving up to the V-drive in a few years so I will get the best of both worlds; fuel economy and room. It's funny how the new inboards are going back to V-drives. They were popular in the 60's and 70's in drag boats and cabin crusers. I had an Howard T-deck, runner buttom years ago. Very fast, but not the best choice for a family ski boat.

rcnjson
07-23-2007, 02:38 PM
I don't think Ford ever built a fuel injected 351W. They did for the 351C and 460.

...

To have someone convert your boat over to a fuel injected engine it would be over $10k.

I'm back...

There are millions and millions of fuel injected 351W's that ford built, it was an engine offered in the most popular vehicle on the planet, the F-150 for years and years, not to mention F-250's, F-350's, Bronco's, and even a few mustangs came with factory 351W EFI. So the parts are out there and very easy to find.

The $10K figure is a little high, I did the conversion on my boat this spring and it was not too bad. Now I will say that I searched for parts and took my time planning what to do and got lucky on a deal here and there, but I did it for less than $500, and I haven't sold my old carb yet.

In an interesting side note, I still have a bunch of parts, including a 351W EFI manifold, injectors, rails, a pump, and computer if you do want to do this conversion. All you would need is a harness and that harness could be from any mass air mustang or truck ($100 on ebay), and then plumb and wire everything.

I won't tell you that this is easy, or that if you can change a tire, you can do this conversion, but it certainly can be done. I am, or more correctly my boat is waterskiing, wakeboarding, barefooting proof of that.

k

flipper
07-23-2007, 02:58 PM
I did mine for about $4k the first time, and about 5k the second. To go to Chevy it was going to be close 15k. Saved a lot of money using what old ford parts I could.

JimN
07-23-2007, 03:21 PM
You can buy a GM Performance Parts crate motor for less than $5K, complete. ECM, harness, motor and unless the transmission won't hook up immediately, it's PNP except for the throttle/shift cable bracket(s). How was $15K justified? For that price, you could buy a '94 boat and it would already have it.

TRBenj
07-23-2007, 03:51 PM
Unless you have a lot of time and knowledge (like rcnjson) I dont think going to EFI is a cost effective modification. Either having someone convert your current motor or dropping in a prebuilt unit will be pretty costly. If you want EFI that badly it might make more sense to sell your boat and shop for another one that had EFI from the factory.

If you decide to hold onto your current boat, your existing motor can be rebuilt with more power for a very reasonable amount of money. A full rebuild or new shortblock can be had for $1500-2500. Another $1500 (parts only) worth of top end upgrades (heads-intake-cam) will add an easy 70-80 hp. Add a new or rebuilt carb, and have it dialed in by a pro- and you'll have the next best thing to EFI.

Personally, I love the 351w. It always felt to me like it had more torque than the 350 Chevy. With the upgrades Ive done, my boat will run with the best of them (and outrun pretty much anything new). If something goes wrong, I can fix it- its much simpler to work on a motor with a carb and an 8-pin engine wiring harness.

flipper
07-23-2007, 03:56 PM
You can buy a GM Performance Parts crate motor for less than $5K, complete. ECM, harness, motor and unless the transmission won't hook up immediately, it's PNP except for the throttle/shift cable bracket(s). How was $15K justified? For that price, you could buy a '94 boat and it would already have it.
Where have you seen a complete marine engine for $5k? You can get an car engine for that price, haven't seen. The price below is a PCM 5.7L. Indmar's go for more.

Price of Bobtail engine (No Trans.) MPI $7395.00 a marine

rcnjson
07-23-2007, 04:45 PM
TRBenj knows what he is talking about. I have seen pictures of his project here and on the CC forums and that boat is put together well. From what I've read it really rips too. The rebuild on the bottom end and a H/C/I upgrade that TRBenj suggested are big bang for the buck. The only reason I converted is I hate carbs. I have always worked on EFI cars and that is what I am comfortable with, they seem so much easier to me. I had all sorts of fits with the carbs (yes I ran 2) last year and I was just sick of it. So I wanted to change it out. Plus, at least the way I perceived it, there were some people who thought it couldn't be done... and I don't like being told no.
k

BrianM
07-23-2007, 06:07 PM
I don't think Ford ever built a fuel injected 351W. They did for the 351C and 460.

.
The first generation Ford Lightning truck used a MPFI 351W. With wate cooled manifolds that would be a nice swap.

bowtie355
07-24-2007, 12:05 AM
I'm back...

There are millions and millions of fuel injected 351W's that ford built, it was an engine offered in the most popular vehicle on the planet, the F-150 for years and years, not to mention F-250's, F-350's, Bronco's, and even a few mustangs came with factory 351W EFI. So the parts are out there and very easy to find.

The $10K figure is a little high, I did the conversion on my boat this spring and it was not too bad. Now I will say that I searched for parts and took my time planning what to do and got lucky on a deal here and there, but I did it for less than $500, and I haven't sold my old carb yet.

In an interesting side note, I still have a bunch of parts, including a 351W EFI manifold, injectors, rails, a pump, and computer if you do want to do this conversion. All you would need is a harness and that harness could be from any mass air mustang or truck ($100 on ebay), and then plumb and wire everything.

I won't tell you that this is easy, or that if you can change a tire, you can do this conversion, but it certainly can be done. I am, or more correctly my boat is waterskiing, wakeboarding, barefooting proof of that.

k

I stand corrected, It's obviously I'm not a Ford fan.
The $10K + figure is to have a shop convert over to a complete power plant not just a FI unit. I think less than $500 to convert over to a port injection is a bit misleading for most people. Most OBD1 or OBD2 computers would have to re-program to map out certain parameters or sensors. That can be $500 by itself. You seemed make it work without programing. I wonder have many error codes your running with?

TRBenj
07-24-2007, 10:30 AM
The first generation Ford Lightning truck used a MPFI 351W. With wate cooled manifolds that would be a nice swap.

The Lightning motor was a basic 351w with GT40 heads. Not sure what the specs on the cam were, but Im guessing it wasnt too aggressive as it was only rated at 240 hp.

The basic EFI components would certainly swap on to a carb'd 351w (intake, etc) but it would be difficult to tune without the right computer programming. Automotive motors are able to tune air/fuel ratios based on readings from an oxygen (o2) sensor in the exhaust- not an easy retrofit for a wet exhaust system.

pilot02
07-24-2007, 10:36 AM
The Lightning motor was a basic 351w with GT40 heads. Not sure what the specs on the cam were, but Im guessing it wasnt too aggressive as it was only rated at 240 hp.

The basic EFI components would certainly swap on to a carb'd 351w (intake, etc) but it would be difficult to tune without the right computer programming. Automotive motors are able to tune air/fuel ratios based on readings from an oxygen (o2) sensor in the exhaust- not an easy retrofit for a wet exhaust system.

The lightning motor was supercharged, correct?? At least my neighbor's was from the factory.

davekro
07-24-2007, 11:17 AM
TRBeng,
I like your idea. EFI is not a top priority, keeping my boat (and slalom wake ;o) is a priority.

Specifically, what changes did you make to your PCM 351W to get 350 HP out of it? That must be a ripper out of the hole with your gear reduction transmission! Was your cost in the range mentioned in your post? DOes the 'another $1500 (parts only)' include new heads? If so, that would be a plus, as one of my heads has a crack at #1 plug hole back towards the head bolt. Has caused no problems, but a rust stain down the block. A grind and weld may fix it, but a new head would give more piece of mind if you are doing a complete rebuild anyway.

Beautiful boat you have!

Dave

TRBenj
07-24-2007, 11:35 AM
TRBeng,
I like your idea. EFI is not a top priority, keeping my boat (and slalom wake ;o) is a priority.

Specifically, what changes did you make to your PCM 351W to get 350 HP out of it? That must be a ripper out of the hole with your gear reduction transmission! Was your cost in the range mentioned in your post? DOes the 'another $1500 (parts only)' include new heads? If so, that would be a plus, as one of my heads has a crack at #1 plug hole back towards the head bolt. Has caused no problems, but a rust stain down the block. A grind and weld may fix it, but a new head would give more piece of mind if you are doing a complete rebuild anyway.

Beautiful boat you have!

Dave


Dave, thanks! Im pretty happy with the way the boat is running. It is very strong out of the hole- I put a few boatlengths on my dad's 196 (330hp) which is no slouch. Top speed is pretty close to 50, but I havent GPS'd it yet. To get to where I am now, I did the entire top end:

-ignition (Performance Distributors DUI)
-intake (Weiand Stealth)
-heads (GT40p)
-roller rockers (FMS 1.6)
-cam (Cam Research custom grind)
-exhaust (Hi-tek SS headers and custom dual conversion)

If you havent upgraded your prop yet (Acme or OJ XMP) then I would do that first- that was the single biggest upgrade I did (and the best bang for the buck).

Last year I was running around with just the ignition, intake, heads and cam and I was running 95% as strong as I am now. I figure I had to be pushing ~320hp. The $1500 I quoted was for all those parts, plus gaskets, bolts, etc. The upgrades can be done for a very reasonable amount of money if you know where to look. Shoot me a PM when you start to make plans and we can get into specifics. Just a note- it is only marginally more expensive ($200-300) to upgrade to HO heads as it is to have a valve job performed on your old ones. I wouldnt even consider fixing the cracked ones you have since the upgrade is so cheap.

I think that is the most cost effective way to go. Roller rockers are not an expensive upgrade, but I cant attest to their worth alone, as I added them at the same time as the exhaust. The exhaust manifolds gave me a nice boost, but they arent cheap (well over $1k), so I wouldnt even consider them unless you have done everything else and want more power (and have money to burn). A friend of mine has a '94 with an LT1 and the thing drives and skis very nice, so I like the idea of keeping your hull.

Pilot, the 2nd gen Lightning did have a supercharged 5.4L motor. The 1st gen (1993-??) had the NA 351w.

davekro
07-26-2007, 10:18 AM
TRBeng,
Thanks for all the info.
On the Prop... What did you change 'from' that you noticed a big difference going to CNC (3blade Acme?)?

Years ago (pre CNC days), I noticed a big plus going from 3 blade OJ 13x13 to 4 blade OJ 13x13. Is there still another significant performance increase from 4 blade non-CNC to CNC? From what I hear, the Acme 3 blade is the one of choice.

Dave

TRBenj
07-26-2007, 11:07 AM
On the Prop... What did you change 'from' that you noticed a big difference going to CNC (3blade Acme?)?


Ive tried a lot of props. On our former boat, we went from a 3-blade Federal to a 4-blade OJ Legend, then to a 4-blade Acme. Each was a significant improvement.

On my boat, I went from the same 4-blade OJ Legend to a 3-blade Acme. Ive tried the 3-blade Acme back to back against the 4-blade Acme on 2 different boats... and the 3-blade held a clear advantage in both holeshot and top end.

davekro
07-26-2007, 01:10 PM
Was the improvement from 4 blade OJ Legend (what I have too) to the Acme 3 blade still another noticeable improvement? (worth the $400?).

Thanks, Dave

TRBenj
07-26-2007, 02:33 PM
The biggest improvement was going from the Legend to the 4-blade Acme on our old boat. On my boat I went straight to the 3-blade Acme (also from the Legend 4)- and its the single biggest improvement Ive made (even with all the engine mods). The difference between the 2 Acme's was smaller, but the performance advantage held by the 3-blade is definitely measurable.

FYI, you should be able to find a 3-blade Acme for closer to $300-350. Dont buy directly from Acme, as they charge full retail in order to protect their dealers. Ive had great luck with Delta Propellor.

davekro
08-20-2007, 08:09 PM
I bought the Acme 541 3 blade 13dx 12p to replace my 4 blade OJ. I was surprised not to notice much difference in measurable specs:
Avg. top end Acme 43 vs. 42.35mph (using perfect pass paddle wheel)
WOT both ran at 4300 RPM!
Initial hole shot rpm was the only significant difference:
Acme 2600
OJ 2900

The Acme did seem to 'bite' better. In very sharp turns, it held well. IF it did cavitate, it as just for a second and re- grabbed (without needing to back off throttle (like I had to with OJ when it cavitated).

If I did not incur the 10% re-stocking fee plus return shipping, I may have returned it. But I think it will grow on me.

Dave
'91 PS 190 240HP

davekro
08-20-2007, 08:24 PM
Leaky head...
After the WOT prop testing, I finally found the mysterious source of extra water in the bilge. I have an ≈1" long horizontal crack on the rear of the left/port head. it goes back from about 1/4" away from the edge of the rear spark plug valley (not near actual threaded plug hole), back around to the freeze plug on back of the head.

With nothing to lose by trying, I dremel stoned around the crack and applied JB Weld, on the off chance that may stop the leak. Actually, if it just the leak, It would not be an issue, as it might let in 1- 1 1/2 gallons during a ski day (not enough to even activate the auto bilge pump).

IF I need to fix this by replacing the head, one friend suggested just bolting on new GT40 heads (which I think I saw recently new for ≈$550 each on line). I have some concern about putting new (or rebuilt) heads on a lower end with 1600 hours on it. That it could cause rings to fail or worse, extra stress to the crank bearings and cause them to fail.

This is all pre-worrying as I won't test last night's JB Weld patch until tomorrow, giving it plenty of time to cure (36+ hrs).

Dave

TRBenj
08-21-2007, 09:56 AM
IF I need to fix this by replacing the head, one friend suggested just bolting on new GT40 heads (which I think I saw recently new for ≈$550 each on line). I have some concern about putting new (or rebuilt) heads on a lower end with 1600 hours on it. That it could cause rings to fail or worse, extra stress to the crank bearings and cause them to fail.

GT40 heads will be harder to find and more expensive than GT40p's. The p's also hold a performance advantage (they flow better and have smaller combustion chambers, which boosts the CR). They can be found fully remanufactured for $350-550 for the SET.

Adding HO heads will not comprimise the engine's internals. The only difference will be the marginally higher RPM that the motor can turn (~300-400). I did all my top end work with 1200 hrs, and have no issues turning 5200RPM all day long.

davekro
08-21-2007, 06:19 PM
TRBenj,
Did you add remanufactured or new GT40(p?) heads to your engine mod? I like the idea of that relatively easy, bolt o fix and performance +.

Just curious of the difference between stock, GT40 & GT40p heads.
If a pair of remanufactured GT40p heads would just bolt on, would a new manifold (cost range?) add more performance/be worth doing too? ( I have a rebuilt Holley 4160). East Texas skier had talked about needing a low profile spark arrestor and maybe cutting away some insulation due to the higher intake manifold (I assume he does not use the plastic cover over spark arrestor).

davekro
08-21-2007, 06:40 PM
TRBenj,
I noted from another post that you have 'p' heads.

Well, my JB Weld did not stop the head crack leak. (no real surprise there. Aside from spraying some water on the interior of engine cover and bilge, I wonder if there is any risk in running as it is? (at least thru this season)

JimN
08-21-2007, 07:22 PM
davekro- anything you can do that will allow the motor to breathe more and better, will help. The exhaust needs to be able to keep up but you're not likely to have any problem with that unless you put a blower or turbo on it. There are some manifolds that will help but they tend to be higher than stock. Look at Jeg's and Summit Racing for ideas and if you need, call them to ask questions.

davekro
08-21-2007, 07:37 PM
Great education for me on GT40p heads at...
http://www.tmcowners.com/teamtalk/showthread.php?t=17963&page=4&highlight=gt40p+heads

Makes me WANT to tear the top end off my engine! (but prefer to wait until winter ;o)
Dave

TRBenj
08-22-2007, 09:12 AM
TRBenj,
Did you add remanufactured or new GT40(p?) heads to your engine mod? I like the idea of that relatively easy, bolt o fix and performance +.

Just curious of the difference between stock, GT40 & GT40p heads.
If a pair of remanufactured GT40p heads would just bolt on, would a new manifold (cost range?) add more performance/be worth doing too? ( I have a rebuilt Holley 4160). East Texas skier had talked about needing a low profile spark arrestor and maybe cutting away some insulation due to the higher intake manifold (I assume he does not use the plastic cover over spark arrestor).

Like you noticed, I did add the P heads. If I had to do it again, I would have bought a remanufactured set. I bought a used set for cheap, and by the time I had a valve job done and new springs installed, I way outspent a reman'd set. Oh well, live and learn.

This article (http://www.stangpro.com/html/articles/gt40p_files/gt40p1.htm) has good info about the P's. To make a long story short, the GT40p's have a smaller exhaust valve than the GT40's (intake valve is the same size), yet the P's outflow them due to a superior design. They also have smaller combustion chambers, so they bump compression about 1 point (to ~9.5:1), which also gives them an advantage.

An intake manifold upgrade is cheap and very easy if you have the heads off. An Edelbrock Performer should give you a noticeable improvement, and is only marginally taller than stock (1.5"). I think Summit sells it for ~$160 brand new.

alp
08-22-2007, 10:10 AM
I discovered the same problem (cracked GT head) in the same location on our 92 PS 190. not much water leaking though. JB didn't work either. It's at 1,160 hours. I'm going to run it easy for the kids skiing for a couple more weeks.

Then comes decision time - rebuild or new long block? Any recommendations? Also planning to have the power slot trans' rebuilt too.

JimN
08-22-2007, 10:24 AM
If the head is cracked, I don't see any reason to rebuild the whole motor unless it was running badly before. A gasket set and some labor is all you would need. 1160 hours isn't a lot.

TCrate
08-22-2007, 09:03 PM
I had three cracks in my GT40 heads. 92 Prostar with 900 hours. I replaced them with RHS heads with larger valves, RPM performer intake. Cost me about 2000 including some labor to have someone help me. I kind of wish I had gone to a different cam while I was at it. it would have been about another $700 bucks. Oh well. next time. Evidently these GT 40 heads have a history of cracking. I have a friend with a 95 nautique, less hours, same problem.

alp
08-27-2007, 10:50 AM
It's running fine. No performance issues at all. We put about 18 hours on it since discovering the crack.

Can the GT heads be replaced with the standard heads from the 250 hp motors? Will the stock intake be ok. Any recommendations on where to get new or remanufactured heads, GT or standard?

Thanks

davekro
08-30-2007, 06:25 PM
I have the standard heads on my 240hp '91 PS 190. The crack/leak recently discovered, actually does not leak that much now. Running at WOT many times for my prop tests did have it spraying enough to wet the carpet out side the motor cover. Now under normal skiing/boarding conditions (≈ 3300 rpm and less), it seems to only dribble.

I have had a long term crack behind the front spark plug on the same (left-port) side. Though I have never 'seen' or noticed extra bilge water from that crack, it does have dry rust streaks down the block.

So If GT40 AND standard (240 hp) 351W heads commonly crack, I wonder if the 'P' heads will have the same problem?

Did GT40p heads come as OEM on tournament boats? Anyone seen this cracking issue on OEM 'p' heads?

TRBenj
09-04-2007, 10:48 AM
I know many people who have 351w's (both stock and GT40 headed)and I dont know anyone who has cracked a head. I wonder if the aforementioned cracks resulted from improper winterization.

The P heads never came on any boats. They only were installed on the '97+ Ford Explorers and Mercury Mountaineers with the 302 (5.0) motor.

davekro
09-04-2007, 08:32 PM
Tim,

Interesting on the 'p' heads, thanks.

Though I rarely get temps below 32 sustained, I always drain the block, risers and heater core as well as (usually) keeping a thermostatically controlled heater wedged under the motor cover ( boat cover on), when Dec/Jan cold snap comes. I guess it is still possible water remains in that rear water jacket and I got a cold snap slip by me. Makes me wonder if forcing c mpressed air thru a water line to the block might be worth doing, trying to lessen any 'pudling'. But then, if there is air space for ice/water to expand to, cracking should not be an issue??

TRBenj
09-05-2007, 11:09 AM
Tim,

Interesting on the 'p' heads, thanks.

Though I rarely get temps below 32 sustained, I always drain the block, risers and heater core as well as (usually) keeping a thermostatically controlled heater wedged under the motor cover ( boat cover on), when Dec/Jan cold snap comes. I guess it is still possible water remains in that rear water jacket and I got a cold snap slip by me. Makes me wonder if forcing c mpressed air thru a water line to the block might be worth doing, trying to lessen any 'pudling'. But then, if there is air space for ice/water to expand to, cracking should not be an issue??

Not sure. Sounds like you would be fine- I know many people simply drain their motors without incident. Refilling the block with antifreeze is a safer bet though- in addition to diluting any water that remains, its good for preventing corrosion.

pdiprete
09-08-2007, 11:19 PM
I know many people who have 351w's (both stock and GT40 headed)and I dont know anyone who has cracked a head. I wonder if the aforementioned cracks resulted from improper winterization.

The P heads never came on any boats. They only were installed on the '97+ Ford Explorers and Mercury Mountaineers with the 302 (5.0) motor.
My original motor (just repowered) had a crack on the port side near the rear of the head. I live near Dave, very rare for us to have even a light freeze let alone a hard freeze that would be required to crack a head. Having said that, it was cracked when I bought it, so I really can't confirm that it wasn't from freezing. Still, freezing in the SF Bay Area?

Cheers,
Peter
PS: Dave! I have 2 more props to test. When you coming out?

davekro
09-14-2007, 04:19 PM
Peter,
How many years and hours did you run with that head crack? I am hoping it is a non issue and I run many more seasons! :o)

Dave
PS, have not pulled the 541 yet... gotta get out there

wade95
09-15-2007, 08:31 AM
Wish I woulda joined this site earlier. I had a GT40 crate motor from ford in my stang and when I upgraded to a different head, cam, intake package I gave away the GT40 iron heads. (They were true gt40 iron heads, had the three bars cast onto the front of the heads and everything. Hell, I woulda given them to you. Sorry.

I think you should just upgrade to a good set of aluminum heads (will drop 50lbs out of the boat) some good 1.6 roller rockers and get back out on the water.

TRBenj
09-17-2007, 11:10 AM
I think you should just upgrade to a good set of aluminum heads (will drop 50lbs out of the boat) some good 1.6 roller rockers and get back out on the water.
Whether aluminum heads on a raw water cooled motor is a good idea is debatable. Unlike an intake manifold, heads are not a cheap part to replace if they succomb to corrosion due to electrolosis or salt.

There are many good sets of iron heads that would be cheaper and more durable in a marine environment.

davekro
10-01-2007, 05:41 PM
My leak (crack) in the head (std 240hp E7 heads) seems to cause no problems so far in my '91 PS190 with 1685 hours. Since I noticed the crack ≈ 9 weeks ago, I have been skiing many times. The only thing I notice is 1" or at most 1 1/2" of water in the bilge at the end of the day. Not even enough to actuate the automatic bilge pump float.
Good thing as I do not have the time or cash to upgrade the motor at this time. But I am extremely thankful to those on this forum (esp. TRBeng) for the education on what to do when I have to. I will definitely go with the 'remanufactured GT40p heads , new cam, new intake manifold' upgrade I have learned so much about!

Thanks to all.