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JaredOSU
10-02-2012, 10:09 PM
What is a reasonable price for remanufactured GT40 heads? Its for a 351 windsor.

1redTA
10-02-2012, 10:38 PM
I have looked for the GT 40p heads, off an explorer V8, they can usually be found on ebay rebuilt for a decent price

nkorep2
10-02-2012, 10:41 PM
There are GT40P heads for sale on ebay for 240 a piece. I dont know the difference between a regular gt40 and the p versions, but those were the ones that were suggested to me. Ill be buying heads soon for my prostar restoration.

j.mccreight@hotmail.com
10-02-2012, 10:46 PM
This pretty much breaks it down.

http://www.fiveohinfo.com/performance/gt40-gt40p.html

Cloaked
10-03-2012, 05:55 PM
My firend bought two rebuilt GT40P heads about six months ago from here:

http://www.tristatecylinderhead.com/index.php?main_page=product_info&cPath=41&products_id=40

Their web site may say they have them in stock but call first.

They build to specs (after contacting you for confirmation of specs). All you'll need to do is use the current push rods and rocker arms. Everything else comes plug-and-play. Request that they drill out the mounting bolt holes to 1/2" diameter. Heads were $300 each and shipping was $40 for two heads (UPS). Took them about 4 days to build. My friend is happy with their deliverable. He ordered a gasket kit from Discount Inboard Marine.

Your mileage and preference may vary.

.

JaredOSU
10-03-2012, 08:54 PM
I am triying to get more speed out of my 89 Prostar. I was told by Discount Inboard Marine to change my propeller and put GT40 heads on. I buy from discount inboard marine whenever possible. They are good people.

j.mccreight@hotmail.com
10-03-2012, 08:57 PM
I am triying to get more speed out of my 89 Prostar. I was told by Discount Inboard Marine to change my propeller and put GT40 heads on. I buy from discount inboard marine whenever possible. They are good people.

A new propeller will be the best bang for your money, what is on there now, I will be trying an Acme 541 this weekend on my 89.

MikeyOrange88
10-03-2012, 09:44 PM
My firend bought two rebuilt GT40P heads about six months ago from here:

http://www.tristatecylinderhead.com/index.php?main_page=product_info&cPath=41&products_id=40

Their web site may say they have them in stock but call first.

They build to specs (after contacting you for confirmation of specs). All you'll need to do is use the current push rods and rocker arms. Everything else comes plug-and-play. Request that they drill out the mounting bolt holes to 1/2" diameter. Heads were $300 each and shipping was $40 for two heads (UPS). Took them about 4 days to build. My friend is happy with their deliverable. He ordered a gasket kit from Discount Inboard Marine.

Your mileage and preference may vary.

.

I can confirm the above as I just purchased and installed GT-40's on my '88 Tristar 351 at the end of July from Tristate. Pricing was $349 per head which included machining the holes to 1/2" and brass freeze plugs per my request. The website listed them for $598/pr. but the machining added another $100 to the bill. Shipping was $21 each. The total invoice was $740 as they did not add any tax. I checked out their online page, but called them to discuss and order. Everything was great, didn't take too long to get either. One suggestion, make sure to tell them brass free plugs and also brass internal plugs (threaded), as well as the holes drilled to 1/2". I didn't mention the internal plugs and they sent regular steel ones in mine.

I ordered the complete gasket set from SkiDIM, but as soon as I click confirm, realized that I had the wrong part no. Called them and they straightened it out no problem. After discussing and realizing that I didn't need the valve seals, etc for the rebuilt heads, he put together a gasket set that contained only the items I need for my project. Saved me a few bucks over the 'complete kit' approach. Those guys are great.

MikeyOrange88
10-03-2012, 09:54 PM
Painting up the new heads. Notice the three vertical bars on the ends designates GT-40.
(4 bars is a GT-40P).

Second pic is all buttoned up and ready for some water.

MikeyOrange88
10-03-2012, 09:56 PM
The pictures worked and on the first try! I'm on a roll now.

Kyle
10-04-2012, 11:26 AM
I am triying to get more speed out of my 89 Prostar. I was told by Discount Inboard Marine to change my propeller and put GT40 heads on. I buy from discount inboard marine whenever possible. They are good people.

You will want a cam too. Your cam is not the HO cam. Also you will need to freshen up the bottom end. New bearings and rings maybe even having a shop bore the bottom end.

I have built my engine and 2 other TT members engines. Do it right. Just changing the heads is not going to give you what you want.

I've met James in this thread before and he knows his stuff. He also has a modified 351w in his Tristar. He and I discussed props at length a week ago. If you are on a budget then I would prop it.


Oh and a set of heads can be had $400-$500. Call your local machine shops.

Dino Don
10-05-2012, 12:31 AM
Got mine from a local salvage yard and pd 80.00 for the pair, GT40P's. Had a machine shop go thur them and all is well. Did bore mine .030 over---flat tops and cam change and balanced the rotating assy. Runs real well-----

sam196370
10-06-2012, 11:24 AM
It seems like putting these heads on a 351w woudln't be that difficult but how difficult was it to get the old manifolds off the stock heads? Any tricks? It seems that many of my exh manifold studs/bolts are frozen and would like to make sure getting them out won't be a pita.

j.mccreight@hotmail.com
10-06-2012, 12:07 PM
It seems like putting these heads on a 351w woudln't be that difficult but how difficult was it to get the old manifolds off the stock heads? Any tricks? It seems that many of my exh manifold studs/bolts are frozen and would like to make sure getting them out won't be a pita.

Soak the exhaust bolts with penetrating oil for a couple days before you try removing them.

Kyle
10-06-2012, 12:28 PM
It seems like putting these heads on a 351w woudln't be that difficult but how difficult was it to get the old manifolds off the stock heads? Any tricks? It seems that many of my exh manifold studs/bolts are frozen and would like to make sure getting them out won't be a pita.

It's easier than you think. Yes you can soak them but I have had no issues with removing the manifolds.

thatsmrmastercraft
10-06-2012, 01:52 PM
Removing the bolts with an impact wrench turned down low and slowly increasing the pressure is a good way to remove bolts that have been in place for a while. I haven't had any problems with the exhaust manifold bolts. A good (not old and stretched out) 6 point socket is always a good plan on old bolts.

cmc87
10-07-2012, 03:02 PM
This pretty much breaks it down.

http://www.fiveohinfo.com/performance/gt40-gt40p.html

Hi guys, I'm the guy that wrote the article above ^^.
I was checking my site traffic and noticed some was coming from this site so I decided to check it out.

For those of you thinking of paying $700 for a set of GT40 heads... think again. That is a crazy price! If you go to a local scrap yard, you can grab a set of GT40/Gt40P's for no more than $100. Have them cleaned up at a good machine shop, new springs if you need (not sure what the cam is like in a marine 351W, but the stock springs aren't very good) and you'll still be out the door under $500, everything included. Another great place to look for these heads is on automotive enthusiast forums (namely ford ones, specifically mustang related). Quite often you can pickup a set for $300-$400 where the previous owner has done all the work, had them cleaned, milled, new springs etc.

What I am so surprised to see however, is that a GT40 head is actually considered an upgrade! What are the power increases you guys are seeing? For a stock 5.0, power gains are typically 30HP, but we're talking 351W here (right?). The GT40 is such a small head for a 351W and moves only a fraction of the air the engine is capable of. Most car guys would laugh at a GT40-headed 351. Does anyone ever use aftermarket heads? Trickflow, Edelbrock, AFR, Ford Racing? Throw some AFR 205's or Trickflow FAC 190's and I'd bet you'd see a world of difference (talking 50+HP gain).

Anyways, I spoke a lot of about cars... just found it really interesting that GT40's are sought after in the marine world too.

I am a boat guy as well (by boat guy, I mean I like boats). I don't have a MasterCraft, mostly cause of $$, but I do have a Seadoo! :) I do wakeboard behind it lol.

Cheers fellas

j.mccreight@hotmail.com
10-07-2012, 04:31 PM
Hi guys, I'm the guy that wrote the article above ^^.
I was checking my site traffic and noticed some was coming from this site so I decided to check it out.

For those of you thinking of paying $700 for a set of GT40 heads... think again. That is a crazy price! If you go to a local scrap yard, you can grab a set of GT40/Gt40P's for no more than $100. Have them cleaned up at a good machine shop, new springs if you need (not sure what the cam is like in a marine 351W, but the stock springs aren't very good) and you'll still be out the door under $500, everything included. Another great place to look for these heads is on automotive enthusiast forums (namely ford ones, specifically mustang related). Quite often you can pickup a set for $300-$400 where the previous owner has done all the work, had them cleaned, milled, new springs etc.

What I am so surprised to see however, is that a GT40 head is actually considered an upgrade! What are the power increases you guys are seeing? For a stock 5.0, power gains are typically 30HP, but we're talking 351W here (right?). The GT40 is such a small head for a 351W and moves only a fraction of the air the engine is capable of. Most car guys would laugh at a GT40-headed 351. Does anyone ever use aftermarket heads? Trickflow, Edelbrock, AFR, Ford Racing? Throw some AFR 205's or Trickflow FAC 190's and I'd bet you'd see a world of difference (talking 50+HP gain).

Anyways, I spoke a lot of about cars... just found it really interesting that GT40's are sought after in the marine world too.

I am a boat guy as well (by boat guy, I mean I like boats). I don't have a MasterCraft, mostly cause of $$, but I do have a Seadoo! :) I do wakeboard behind it lol.

Cheers fellas

Generally these inboard engines don't do very well with aluminum heads with cool lake water and hot iron blocks. Personally I put iron windsor sr. 200 on my 351w, flow more air than gt40p but not as much as aluminum aftermarket heads. Another reason for the gt40 its a direct swap for the e5ae or e8jl heads that came stock on our engines and gives a nice little boost in hp and torque that you can feel out on the water, with most owners able to do the work themselves in a weekend.

MikeyOrange88
10-08-2012, 09:20 AM
Hi guys, I'm the guy that wrote the article above ^^.
I was checking my site traffic and noticed some was coming from this site so I decided to check it out.

For those of you thinking of paying $700 for a set of GT40 heads... think again. That is a crazy price! If you go to a local scrap yard, you can grab a set of GT40/Gt40P's for no more than $100. Have them cleaned up at a good machine shop, new springs if you need (not sure what the cam is like in a marine 351W, but the stock springs aren't very good) and you'll still be out the door under $500, everything included. Another great place to look for these heads is on automotive enthusiast forums (namely ford ones, specifically mustang related). Quite often you can pickup a set for $300-$400 where the previous owner has done all the work, had them cleaned, milled, new springs etc.

What I am so surprised to see however, is that a GT40 head is actually considered an upgrade! What are the power increases you guys are seeing? For a stock 5.0, power gains are typically 30HP, but we're talking 351W here (right?). The GT40 is such a small head for a 351W and moves only a fraction of the air the engine is capable of. Most car guys would laugh at a GT40-headed 351. Does anyone ever use aftermarket heads? Trickflow, Edelbrock, AFR, Ford Racing? Throw some AFR 205's or Trickflow FAC 190's and I'd bet you'd see a world of difference (talking 50+HP gain).

Anyways, I spoke a lot of about cars... just found it really interesting that GT40's are sought after in the marine world too.

I am a boat guy as well (by boat guy, I mean I like boats). I don't have a MasterCraft, mostly cause of $$, but I do have a Seadoo! :) I do wakeboard behind it lol.

Cheers fellas

For my situation, I wasn't replacing the heads on mine strictly as an upgrade modification, I had a leaking head that was dumping water into #8 cylinder, hence the replacement. As for the cost, I didn't like the risk of trying to obtain that type of part from an unknown source, especially Craigslist type, since any issues with the heads would not be necessarily visible until a machine shop gets into them. I was pleased with the quality, just had to paint them and put them on. They were completely remanufactured with new stainless steel valves, springs, seals, etc. Putting them on a 351W also requires that they be machined for 1/2" headbolts, which they did as well. I suppose you could save some money by going about another way, just wasn't for me.

cmc87
10-08-2012, 03:28 PM
Generally these inboard engines don't do very well with aluminum heads with cool lake water and hot iron blocks. Personally I put iron windsor sr. 200 on my 351w, flow more air than gt40p but not as much as aluminum aftermarket heads. Another reason for the gt40 its a direct swap for the e5ae or e8jl heads that came stock on our engines and gives a nice little boost in hp and torque that you can feel out on the water, with most owners able to do the work themselves in a weekend.

Good point, did not consider open cooling. Stuck in car mode I guess :P Yes then like you did, Windsor Sr's will be miles above GT40's.

For my situation, I wasn't replacing the heads on mine strictly as an upgrade modification, I had a leaking head that was dumping water into #8 cylinder, hence the replacement. As for the cost, I didn't like the risk of trying to obtain that type of part from an unknown source, especially Craigslist type, since any issues with the heads would not be necessarily visible until a machine shop gets into them. I was pleased with the quality, just had to paint them and put them on. They were completely remanufactured with new stainless steel valves, springs, seals, etc. Putting them on a 351W also requires that they be machined for 1/2" headbolts, which they did as well. I suppose you could save some money by going about another way, just wasn't for me.

The only thing that matters at the end of the day is that YOU are happy with what you got. I agree, CL has deals, but you don't always know what you might be getting. However, a great source for cheap GT40's is corral.net classifieds. Most guys there selling stuff are reputable and know what they are talking about. In the case of a bad transaction, the guilty party will literally be roasted by every other member on the site. Usually paypal will cover you too.

Just another perspective :)
Out of curiosity, does anyone port their stock heads? I am unfamiliar with the E8 variety mentioned above, but do know E5's. I presume the E8 is the marine coded version of the E7?

TRBenj
10-09-2012, 02:41 PM
Not worthwhile to port the stock low compression, low flow heads (E7's, etc). Definitely not worth it to pay someone either. Not when P heads are available for $400 (fully rebuilt). Its not really cost effective to buy used GT40p's and have them gone through either... unless you can snag a pair for <$100. Valve jobs are $300+ around here.

GT40's did come stock on the "HO" marine 351w's, to the tune of 285-310hp. They were much stronger performers than the 240hp non-HO versions. While GT40 and GT40p heads are largely considered too small for an automotive build, the typical upgrades on these boats are significantly milder. Max RPM's (prop limited) are usually in the 4400-4600rpm range on the non-HO boats, and 4800-5000rpm on the HO versions. Cams for both set ups are pretty small (~.450 lift) from the factory... so the better Ford cast iron heads work well.

A 300-325hp 351w makes for an extremely competent ski boat, and is likely why few people push the hp limits beyond that. In direct drive form (tournament inboards), hull is going to be the limiting factor if top end speed is a major concern (and it usually isnt anyways).

That being said, no other reason not to use nicer heads like Trick Flow, AFR, RHS, etc. other than the additional cost- especially when a higher performance build is planned. Corrosion isnt really a factor unless youre running in salt (many people have aluminum intake manifolds, after all). A handful of people have utilized better heads and have pushed these water tractors well beyond their intended speeds. Funny things can start to happen from a handling perspective though- not for the feint of heart.

Dino Don
10-10-2012, 11:07 PM
A handful of people have utilized better heads and have pushed these water tractors well beyond their intended speeds. Funny things can start to happen from a handling perspective though- not for the feint of heart.

This is true--have found out they dance on the tail when the speeds get up. :D

TRBenj
10-11-2012, 11:45 AM
This is true--have found out they dance on the tail when the speeds get up. :D
Thats a term I havent heard before... can you describe?

Phntmski
10-11-2012, 01:30 PM
Don't remember ever hearing of Windsor SR's. Just looked them up online, interesting. As I just finished an overhaul I won't be making any changes soon but I am wondering what I left on the table. I'm guessing I'd need a more aggressive cam with them over the GT40p's I did use, which set me back about $350 complete.

Dino Don
10-11-2012, 01:57 PM
Thats a term I havent heard before... can you describe?

My 190 when the speed gets up and you hit a little chop the thing feels somewhat unstable. My Dad had a marine business and we could take a lite weight boat and over power it and it would do the same thing. The other post talking about "water tractor" sort of addressed the issue. These boats are power boats for pulling and apparently don't repond very well at higher speeds. Maybe jack plates would help but I perfer just pulling back on the throtle in choppy water. Also my boat isn't as heavy as the newer ones are.

DooSPX
10-11-2012, 02:14 PM
Heck, Dino, my 91 can get a little tail happy in decent chop at 45mph and its stock. It requires more wheel input, where as smooth water, nothing at all.

TRBenj
10-11-2012, 02:44 PM
My 190 when the speed gets up and you hit a little chop the thing feels somewhat unstable. My Dad had a marine business and we could take a lite weight boat and over power it and it would do the same thing. The other post talking about "water tractor" sort of addressed the issue. These boats are power boats for pulling and apparently don't repond very well at higher speeds. Maybe jack plates would help but I perfer just pulling back on the throtle in choppy water. Also my boat isn't as heavy as the newer ones are.
I understand instability at high speeds and have experienced it many times. Ive piloted several inboard ski boats that flirt with the 60mph mark. Just not sure what is meant by "tail dance" or "tail happy". Can you be a little more descriptive?

Generally speaking, a light wind chop is the safest water condition- and fastest. Glass calm water may cause some weird stuff to happen sooner, and rogue wakes or heavy chop can be downright dangerous.

LYNRDSKYNRD
10-11-2012, 03:10 PM
Funny things can start to happen from a handling perspective though- not for the feint of heart.

What types of "funny things that start happen" Can you be a little more descriptive?

cbryan70
10-11-2012, 03:10 PM
Maybe chine walking? the prop is pushing the back end of the boat up out of the water and at the higher speeds it gets worse.

TRBenj
10-11-2012, 03:18 PM
Ive seen chine lock happen, and have experienced what I believe to be rudder stall... the former can take the boat and abruptly push it in a new direction (without steering input). The latter results in a loss of rudder control- which Ive heard can do scary things, but when it happened to me, it was a slow degradation and never resulted in a dangerous maneuver. Some boats boats will nose steer, which may or may not become scary and dangerous.

Not sure if "tail happy" or "tail dancing" would fit under any of those categories... doesnt seem quite the same to me.

j.mccreight@hotmail.com
10-11-2012, 04:57 PM
With my new found power in my 351w after my engine work I was experiencing maybe this, chine walking, cavitation, rudder stall, nose steer call it what you want. My boat would start to pull very hard to starboard the faster I went kinda unsettleing at 46mph. I felt like if I released the steering wheel it would throw me into a hard power turn, I could control the pull and the boat but had to apply quite abit of port steering to maintain straight ahead. I thought I might had been cavitating the propeller so I ordered a new Acme 541 and the pull was still there albeit maybe 75% as strong I was turning 4750 rpm @ 46 mph. Another prop will be here tomorrow and we will see how it goes.

TRBenj
10-12-2012, 11:11 AM
The speed and power levels youre talking about are generally pretty safe. The unsettling behavior usually starts in the mid to upper 50's, at least on the hulls I have played with.

If your revs were climbing out of control and not translating to forward motion, then that is what would make me suspect cavitation... 46mph @ 4800 rpm would not lead me in that direction. Those numbers seem typical of a 300-325hp 351w.

j.mccreight@hotmail.com
10-12-2012, 01:13 PM
The speed and power levels youre talking about are generally pretty safe. The unsettling behavior usually starts in the mid to upper 50's, at least on the hulls I have played with.

If your revs were climbing out of control and not translating to forward motion, then that is what would make me suspect cavitation... 46mph @ 4800 rpm would not lead me in that direction. Those numbers seem typical of a 300-325hp 351w.

I don't know why you always come on this forum and degrade others for their engine modifications, I am happy with my changes, I was not asking for a hp rating for my engine. Yes I asked you about a prop recommendation but I also asked 5 other people the same question including both propeller manufactures. All I know my boat is traveling 46 mph which is what MC claimed in the owners manual as the top speed, and pulls hard to starboard with a 3 blade propeller, the original federal and the acme 541 but does not pull with either oj 4 blade propeller. I have tried 4 props on my boat to date. I have another propeller that arrived this morning and will be trying it out tomorrow. The federal has been reworked once before as well as the oj's the acme is new.

If your saying that pulls don't start until the mid 50's, how do you explain it on my boat at 46 and only with 3 blade propellers.

TRBenj
10-12-2012, 01:47 PM
Pulling in one direction might have something to do with rudder tune? Maybe a little bow steer mixed in? That can happen at slower speeds on nose-planted hulls. The unsettling behavior I was talking about had more to do with loss of control and/or abrubt, unplanned maneuvers- which usually occur at speeds and power levels well in excess of the common 300-325hp GT40 head type packages.

Not sure what comments you took as degrading, they certainly werent meant as such. My best all around ski boat puts out similar performance numbers, and I dont consider it a slouch.

j.mccreight@hotmail.com
10-12-2012, 01:52 PM
My rudder has not been filed, my boat drives straight with oj 13x14 4 blade at 45 mph and pulls with either 3 blade both do 46mph. I just dont understand why with such a small window in terms of mph it pulls starboard...

cmc87
10-12-2012, 02:36 PM
Don't remember ever hearing of Windsor SR's. Just looked them up online, interesting. As I just finished an overhaul I won't be making any changes soon but I am wondering what I left on the table. I'm guessing I'd need a more aggressive cam with them over the GT40p's I did use, which set me back about $350 complete.

Yeah with a proper matching cam there's easily a 50HP/tq difference. $350 for a set of GT40's is a good deal when all said and done. Does the marine world change the springs on the GT40ps? I know the Mustang world (where I am from, the ford 5.0!) the stock springs won't handle a stock Mustang cam (lift of .444, 266/266 @ 0.06" duration)

TRBenj
10-12-2012, 02:43 PM
Everything Ive read indicates that the stock P valvesprings are good for lifts approaching .500. Stock 351w marine cams are in the .450 ballpark and dont require new springs.

cmc87
10-12-2012, 10:10 PM
Everything Ive read indicates that the stock P valvesprings are good for lifts approaching .500. Stock 351w marine cams are in the .450 ballpark and dont require new springs.

Interesting. All car guys will say, including myself, the stock springs are junk. What is max RPM of these marine 351ws? My Stang will churn out 6200 rpm. At these higher RPM's, I'd say 5500+ is asking to first float, than drop some valves. I see from a post above that most of these boats max out around 45MPH at 4800rpm. I suppose red line is 5000?

Oddly enough, I am now looking for a wakeboarding boat lol. Been intending to pick up a used bow rider for some giggles next year, but now I keep finding myself searching up info about a real inboard. :o

j.mccreight@hotmail.com
10-12-2012, 10:25 PM
Interesting. All car guys will say, including myself, the stock springs are junk. What is max RPM of these marine 351ws? My Stang will churn out 6200 rpm. At these higher RPM's, I'd say 5500+ is asking to first float, than drop some valves. I see from a post above that most of these boats max out around 45MPH at 4800rpm. I suppose red line is 5000?

Oddly enough, I am now looking for a wakeboarding boat lol. Been intending to pick up a used bow rider for some giggles next year, but now I keep finding myself searching up info about a real inboard. :o

4400-4600 is usually max rpm on a stock engine depending on how its propped, a modded engine will reach 4800 maybe a tic above, alot of variables in engines, transmission, hulls, and propellers, which is my woe at the moment, trying to find the perfect prop for my application for my mods.

TX Wind
10-14-2012, 02:10 AM
What is a reasonable price for remanufactured GT40 heads? Its for a 351 windsor.

It's my understanding that the GT 40p is the one you want.

cmc87
10-19-2012, 03:40 AM
It's my understanding that the GT 40p is the one you want.
GT40, GT40P - basically the same thing. Performance wise, not much of a difference (MAYBE 5hp). Mind you, GT40P has different spark plug placement and thus can require special headers - not sure about the OE headers on a marine 351W, whether they work better with the P or regular GT40's... If they work with the P heads, they ought to work with the regular GT40's.

TRBenj
10-19-2012, 10:00 AM
GT40, GT40P - basically the same thing. Performance wise, not much of a difference (MAYBE 5hp). Mind you, GT40P has different spark plug placement and thus can require special headers - not sure about the OE headers on a marine 351W, whether they work better with the P or regular GT40's... If they work with the P heads, they ought to work with the regular GT40's.
They may share some very basic design aspects (both being factory Ford Windsor cast iron heads) but they are not "basically the same thing". P's have smaller exhaust valves, smaller combustion chambers, different spark plug angle, and flow better both intake and exhaust up to ~.500 of lift.

Power levels will be *similar*, but the P's will have an advantage in a ski boat application. Few 351w's have cams larger than .500 of lift (and thus the P's will flow better), plus the low compression marine long blocks get a nice CR boost with the smaller chambers (~9-9.5:1 from low 8's).

GT40's are more highly sought after on the automotive side because they flow better with bigger cams and dont require special headers due to the spark plug angle (a non-issue for upswept marine manifolds). That higher demand (plus lower supply since GT40's were never used in high volume production vehicles) keeps their (used) prices higher. P's are better, more readily available, and cheaper. Win/win/win.

clrussell
10-19-2012, 01:07 PM
So on the Marine side if a guy was going to install gt-40p heads would a cam change be recommended? And what about intake?


Sent by the new iPhone 5!

Kyle
10-19-2012, 01:39 PM
So on the Marine side if a guy was going to install gt-40p heads would a cam change be recommended? And what about intake?


Sent by the new iPhone 5!

I added heads cam and intake.

I would do it again in a second if I had a 240hp engine that was factory in the older boats.

I gained 5-6 mph, more efficient, way more hole shot, etc.

So HE|| yes add cam and intake. It made mine BADA$$

TRBenj
10-19-2012, 02:38 PM
So on the Marine side if a guy was going to install gt-40p heads would a cam change be recommended? And what about intake?


Sent by the new iPhone 5!
From a performance aspect, absolutely. A higher flowing intake to match the higher flowing heads, and a cam that ties everything together will optimize your performance. Its not an absolute requirement based on reliability or parts interchangeability though.

clrussell
10-19-2012, 03:13 PM
Where would i find the right cam? Aren't marine cams different than automotive? And I don't run mine much on top end so would like a performer intake be better than a performer rpm?


Sent by the new iPhone 5!

Phntmski
10-19-2012, 03:28 PM
Cam Research in Denver is a great source. Not only are they Ford guys they're skiers to boot! They understand we're looking for hole shot and mid-range torque, not necessarily speed. I've dealt with them and not only do.they have great product, the service is second to none.

I'm sure there are other good sources but I have had good experiences with CR.

clrussell
10-19-2012, 03:55 PM
Thanks! I'll check em out and see what they say!


Sent by the new iPhone 5!

Phntmski
10-19-2012, 04:09 PM
Let us know what you find out. And for the record, yes, Performer intake reache and maintain peak performance at lower rpms than the Performer RPM. Again, when I did my engine I wanted low to mid-range torque, not WOT crazy speed. That's not what these boats are designed for. Don't know about all boats but with my PS, the faster she goes, the more resistance to more speed she produces.....but the wakes and solid pull are 'oh so nice".

:D

clrussell
10-19-2012, 05:00 PM
Well it's either a tear down on a good boat or a good 71 engine this winter! Both about the same work, wanting to do a cam swap on my 71, wanting to do heads, intake and cam on the boat! Why not do the boat I say, I havnt had that engine apart yet


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Dino Don
10-19-2012, 10:23 PM
I added heads cam and intake.

I would do it again in a second if I had a 240hp engine that was factory in the older boats.

I gained 5-6 mph, more efficient, way more hole shot, etc.

So HE|| yes add cam and intake. It made mine BADA$$

Mine too!!! Like it!

j.mccreight@hotmail.com
10-19-2012, 10:40 PM
Mine too!!! Like it!

Yep, I picked up ~500 rpm and ~3 mph.

clrussell
10-19-2012, 11:29 PM
Well y'all have made up my mind.. Tower, ballast, and engine work should make for a completely different boat next year!


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