View Full Version : Engine refresh/rebuild success!

03-15-2005, 11:17 AM
This might be long and it's been slow around here lately, so here goes.

A couple of years ago I bought a remanufactured marine long block from a good source to repower my 84(pics have been posted of it here before). The engine itself was fine and has worked very good for 100 hours, however a mistake I stupidly made prevented 3 of the cylinders from sealing properly. Essentially it overheated on break in, good for the cam, not so good for the piston rings.

Long story short, I installed the raw water pump on backwards, so instead of pulling water in, it was pushing water back out. Once I installed the pump, the right way, the temperature came down and it seemed to settle in. It made good power, but I was consistently oil fouling 3 plugs over the course of a season. I knew what the problem was and I knew I would have to fix it eventually, so I decided to go ahead and bite the bullet this off season and tear it apart, rehone the cylinders and re-ring the pistons. I figured I would replace all the bearings as well too, since I would be in there anyway.

Once I got the engine apart and could see what had happened, it basically confirmed what I had originally feared. Glazed cylinder walls, caused from overheating. I checked out the bearing surfaces and they a looked brand new! That was great news! The block is essentially at the end of it's serviceable life as told by the overbore at 4.060, which is fine on a 351. I knew the deglazing wouldn't take too much material, if any, and I was going to use a good set of Sealed Power file fit rings to fit them to each cylinder perfectly. By the way, the cylinders had almost no taper to them what so ever, even more good news! So the honing began. The cross hatch pattern was not as difficult to master as I thought it was going to be with the honing stones. Actually very easy and fast. It was nice when I was done to see the cylinders look brand new.

I figured since I had it apart, I would also put a set of GT-40 heads and some nice FRPP roller rockers from my 94 Cobra on it I had lying around. Took the heads to a machine shop to clean and inspect, valve job, mounting holes drilled to accept 1/2" head bolts and brass freeze plugs installed. The heads checked out, so all was good.

Once I had everything I needed, I cleaned the block completely and set out to reassembled everything. I checked tolerances as directed, checked tolerances as directed some more and o yeah, did I mention checked tolerances? It really isn't that hard to do if you have the right tools, measuring instruments and most important of all, PATIENCE! I took about a month to completely assemble it, working on it a few hours a week. No stress was my motto when going about it. I had plenty of time and a warm garage to work.

You don't know how happy I was when I laid all the new bearing inserts, lubed and torqued everything down, that it spun very freely and smoothly. So, flash forward to the moment I go to turn the key last weekend to see if all my hard work paid off. It fired right up, no leaks, no overheating, oil pressure was over 40 psi at start up and would rise and fall with engine rpm! The hotest it got was about 160. I did a few happy jumps and shut her down after about 15 minutes. I won't be able to give it a true test until I can get her out on the lake, but I think it should be fine.

It sounds very different now too, which was a very nice side effect to this project. It is very racey sounding and it revs very easily. Sounds mean. I didn't have time to tune it, set timing or anything. That will be the next thing that I will do.

All in all, I would do it all over again and it was fun performing everything on my own. I learned alot and I think I am going to rebuild that 94 Cobra motor I have and turn it into a marine engine as well. Possibly sell it. We will see. Anyone in the market for a 302!

If you want to ask me questions about things I did not include or you want to know about, just ask. I'll try to answer your questions as best I can. I'll post pictures of my build from start to finish as soon as I can get them off my camera.

Long time lurker, recent poster. Have a great day!

03-15-2005, 11:30 AM
I'm glad everything worked out for you. Thank goodness that you were able to have "no stress" time to do everything right. Sounds like you did a good job.

east tx skier
03-15-2005, 11:39 AM
Sorry Brian, but Martini may have just gotten by you on the winter projects. :)

Great job. Keep us posted on your lake test.

03-15-2005, 11:46 AM
Great work, hope it runs fine in the water.

03-15-2005, 12:00 PM
I forgot to list the components installed and specs. 351w overbored .060, GT-40 heads, 1.60 FRPP roller rockers, stock intake, MSD coil, electronic ignition, 1" inch carb spacer(to prevent heat soak and it works), Edelbrock marine carb, all fuel lines plumbed with AN fittings and hoses, adjustable fuel pressure regulator and fuel pressure gauge(Edelbrocks are finicky about PSI). And a newly aqcuired Acme prop.

03-15-2005, 12:14 PM
you'll love the acme prop!!!!!!

03-15-2005, 12:47 PM
Very impressive. Sounds like a good learning experience. I would enjoy doing something similar but I don't have any excuse to take mine apart since everything works well. Guess I shouldn't complain too much about that!

I have heard so much about the GT40 heads that that alone might be a good project. Probably not for awhile though.

03-15-2005, 12:58 PM
that is love and dedication. how long did it take to do the whole project?

03-15-2005, 01:04 PM
Anyone know if the aluminum GT-40 heads would be ok to put on the boat motor?

Jegs has them for about $100.00 cheaper than SKIDIM.com

03-15-2005, 01:35 PM
Thats great. I just bought my boat and the starter had died from having a leaky water pump. Had the starter rebuilt and a new water pump and everything was great! This weekend I took it out to find that at the end of one of the risers has a leak in the rubber tubeing towards the end of the boat. Well I didn't think it was that bad so I keep the bilge pump on and off I went. Came back to the ramp in line with all the other club boats after the show to put it back on the trailer. Made the mistake of turning her off to go get my car. Big Mistake!!! It wouldn't start!!! Found out the I still had enough water for the fly wheel to pick up water and kill my brand new starter. So I had to pull the boat on the trailer which made me so mad. I havn't taken it apart yet myself to see if I can get it to work or have it rebuilt again! Sad Day!!!

03-15-2005, 01:53 PM
Sounds like a great winter project! I would like to do the same.

If you don't mind me asking, how much did all this cost?

03-15-2005, 02:39 PM
Jay, it has not stopped since I bought it in February 2002, LOL! It is really an ongoing project and fits my "tinkering" needs. It's not a car that is my only transportation, so that alone takes the pressure off of getting everything done quickly. Also, it is very easy to work on. Time will tell when I will consider it "done".

Powerslot, This most recent engine improvement/upgrade/repair cost me about $500 for everything. That includes machine shop fees, hardware, piston rings, bearings and gaskets(head gaskets alone were $50). Of course that includes oils, assembly lube, thread sealer, gasket sealer, etc. I did have to buy a few engine assembly tools and measuring instruments, but I don't count that, as I will be able to add them to my tool inventory. They were also mostly Christmas presents anyway.

03-15-2005, 02:46 PM

Why not try and pick up a set of GT-40P iron heads? These are cheaper than the aluminums and they will work perfectly on our boats. They have a slightly modified spark plug location, apparently making them a little better the original GT-40 heads. They were originally sold on Explorers and I know they are readily available. Just a thought.

03-21-2005, 03:02 PM
What is the difference in the gt-40, and the gt-40p heads?

Are the Brass freeze plugs the only difference in the marine heads, and the standard automotive?

My heads had small water leaks in them. Causeing the water to seep out when it is running. Nothing in the oil yet. Motor runs fine.
I sealed them with liquid steel. so far so good.

I feel I need to change the heads soon though.

03-21-2005, 03:27 PM
The "P" head was designed for the Explorer's that had the 5.0 installed in them. Their sparkplug location is different than on the original GT-40. Basically the "p" spark plug will be sticking straight out of the head, instead of the angle it currently does on the regular GT-40. This would pose a problem if you were installing these heads on a late model mustang, where the headers would cause interference with the spark plug. Since a boat has an exhaust manifold that angles up instead of down, there is no interference. Brass plugs are the only real difference between a marine and auto head.

03-24-2005, 04:18 PM

04-22-2005, 08:45 PM
Well, as promised here are the pictures of my rebuild/rering project over the winter. I'll post more pictures of the short block build when I can find the memory card from my camera. The pictures start from the shortblock and go from there.
Break in was no big deal, except for the fact that it likes to drink the GAS alot faster than it did before! ;) Hole shot is second-to-none and it revs very fast now. All cylinders sealed, no oil burning no leaks either! The time it takes to reach top speed is very, very quick. I wimped out at 47mph, but think it could reach 50 very easily. We'll see. So enjoy.

04-22-2005, 08:46 PM

04-22-2005, 08:47 PM

04-22-2005, 08:48 PM

04-22-2005, 08:51 PM

04-22-2005, 08:52 PM

04-22-2005, 08:53 PM

04-22-2005, 08:54 PM

04-22-2005, 08:54 PM

04-22-2005, 08:55 PM

04-22-2005, 08:58 PM
Let's see if this works.

04-22-2005, 08:58 PM
And last but not least.............

04-22-2005, 09:00 PM
Looks great,

How near complete are you? It sure looks ready to go, :toast: ..

04-22-2005, 09:03 PM
She's done.................................for now.

04-22-2005, 09:09 PM
Sweet!! Well get it wet..:headbang:

04-22-2005, 09:43 PM
I think I will do just that, tomorrow.

04-22-2005, 11:39 PM

04-22-2005, 11:56 PM
Now that is really neat Martini.

Thanks for sharing. Looks really nice.

04-23-2005, 12:32 AM

I must have missed something on his last post????

04-23-2005, 10:50 AM
no you didn't miss anything erkoehler, I was giving it a bump to the top. Just like I am now! jk

04-23-2005, 11:13 AM
got it, ttt

04-23-2005, 11:13 AM
Got any pics of the whole boat?

04-23-2005, 11:25 AM
Great looking engine Martini!
Hope your hard work will pays off in good time on your boat.

04-23-2005, 11:28 AM

Did we get the shots of your boat yet??

JK man, My Team Talk membership may have come a few days before my Mastercraft purchase.

04-23-2005, 06:10 PM
Took this shot this afternoon.

04-23-2005, 06:34 PM
I will give you some shots of our NON-mastercraft on memorial day when it comes out of hibernation.

Then some shots of the club boats later in the summer.

east tx skier
10-14-2005, 03:49 PM
Martini, can you reload the pictures? Such a great project.

10-14-2005, 03:57 PM
Sure. I will reload them again tomorrow.

10-14-2005, 04:01 PM
I have a picture of the completed engine on my work computer so enjoy.

east tx skier
10-14-2005, 04:04 PM
Can't wait to see them.

Oh, wait. I see one. Ooooooh, pretty!

Just found a source for Taylor wires a block from my house. How convenient for me. Contemplating a color other than black.

10-14-2005, 04:15 PM
Thank you, I will probably go ahead and replace the heads on this new-to-me boat this winter and paint it in the same scheme. I will rebuild the carb at that time as well.

10-18-2005, 01:02 PM
I have posted this project's pictures in my profile, under 84S&S.

10-18-2005, 01:08 PM
That's an awesome job Martini! I imagine it runs just as good as it looks! :steering:

10-18-2005, 03:26 PM
It certainly did. Sadly that boat and engine are with someone else now.