57 250 HP Fulie Engine Rebuild

[David C.]

I am restoring my 57 and before I get into rebuilding the engine I have a few questions.

1) If it requires boring, what pistons should I use?
2) Should the original rods be used? Rod bolts?
3) I want to keep it fairly stock with hydraulic lifters and cam. Who makes a replacement cam and lifters? Part Numbers??
4) Anything special about rebuilding the heads? - Seals and etc?
5) Higher pressure oil pump?
6) What Timing Chain manufacturer?
7) Gasket set supplier?

This car will never be raced or anything like that, so original horsepower will be fine!

Thanks

[Joe R.]

Re: 57 250 HP Fulie Engine Rebuild

I am restoring my 57 and before I get into rebuilding the engine I have a few questions.

1) If it requires boring, what pistons should I use?
2) Should the original rods be used? Rod bolts?
3) I want to keep it fairly stock with hydraulic lifters and cam. Who makes a replacement cam and lifters? Part Numbers??
4) Anything special about rebuilding the heads? - Seals and etc?
5) Higher pressure oil pump?
6) What Timing Chain manufacturer?
7) Gasket set supplier?

This car will never be raced or anything like that, so original horsepower will be fine!

Thanks

David,

This is a bit out of my league, but I will at least get you bumped back up to the top of the heap. You can probably use Federal Mogul (Sealed Power) parts for most of the parts, available at NAPA and elsewhere. I would not reuse original rods or rod bolts. It will cost about the same or maybe less to buy new. Better to buy peace of mind here. What cam do you have? If you have GM part numbers you can punch them into NAPA's web site. I think it's napaonline.com. I would not recommend a higher pressure oil pump. There's a reason the General set up the oiling system the way they did. Fel-Pro gaskets are good.

You probably already know this, but don't let the machinist deck the right side of the block. I would manage the compression ratio (CR) to get the most power out of the engine on high octane pump gas. That means taking some measurements once the engine is apart. You may not want extra horsepower, but I wouldn't let the machinist talk you into dropping the compression ratio very much either. That will turn your engine into a real dog. If it doesn't detonate now, you don't need to drop the CR. I would show up at the machine shop with all parts that will be installed already in hand. That way you will know what's in your engine.

Does your engine have any known weak points? For example, the early 327's had weak rods. You can find the answers here. Lastly, I would search the archives to see who has recently been down this path. Ask them for guidance.

Good luck and may the force be with you!

Joe

[Duke W.]

Re: 57 250 HP Fulie Engine Rebuild

I am restoring my 57 and before I get into rebuilding the engine I have a few questions.

1) If it requires boring, what pistons should I use?
2) Should the original rods be used? Rod bolts?
3) I want to keep it fairly stock with hydraulic lifters and cam. Who makes a replacement cam and lifters? Part Numbers??
4) Anything special about rebuilding the heads? - Seals and etc?
5) Higher pressure oil pump?
6) What Timing Chain manufacturer?
7) Gasket set supplier?

This car will never be raced or anything like that, so original horsepower will be fine!

Thanks

1. Go to www.napaonline.com and use the online catalog to find all the correct Sealed Power OE replacement parts. As far as pistons are concerned, the OE advertised CR is only 9.5:1, and you can go higher to 10:1 on modern premium. Also google Keith Black pistons and see what they have to offer. See the Fall 2009 Corvette Restorer to learn how to MANAGE the CR.

2. The original rods are weak. You can either buy a set of Eagle SIR rods or a cheaper alternative is a set of used SECOND DESIGN 327 rods. A lot of guys replace these when rebuilding their SHP/FI 327s to 7000 rev screamers, but they will be fine for a 5500 rev 283 - much better than the OE 283 rods. There should be sets laying around out there. This rod issue has been discussed here many times including photos to both first and second design, so you can recognize them. The second design went into production some time in the '66 model year. Of course you will have to have the cranktrain precision balanced.

3. The OE cam is long discontinued and has some design deficiencies. It was replaced by the 3896929 in 1966 - Sealed Power CS-274.

4. Since you are not looking for "more power" all you need to do is rebuild the guides and grind the valves. Talk to your machine shop about what guide rebuilding technology they offer and make sure the seal technology is compatible with the guides. Cast iron guide inserts with the OE type O-ring seal are perfectly adequate. DO NOT have hardened exhaust seat inserts installed and DO NOT surface the head if it measures flat with a machinists' bar and .0015 feeler gage.

5. Disassemble the OE pump and inspect it. There's about a 99 percent chance that is is perfectly useable. DO NOT increase the OE oil pressure. (See the nearby thread on this subject.)

6. Use the inexpensive Sealed Power OE replacement silent chain. You DO NOT need and expensive "roller chain".

7. Any name brand gasket supplier is fine, but there are some judging issues with the visible manifold gaskets if you are chasing points - many discussions on this subject and there are some that judge well. The OE head gasket is a .018" shim type, and the Felpro 1094 .015" coated shim type will be fine if the head and block surfaces are flat as described above, and most will measure flat. Most rebuilders like to use a thick compostion gasket, but this will cost nearly half a point compression - fine if you want to give up the torque/power and use regular fuel, but not something I would accept.

The most important part of engine restoration is PLANNING - know what you want and generate a written list of replacment parts BEFORE you start the project. Remember, YOU are the project manager. The machine shop is just a vendor that performs the specfic work you order. If they insist on doing it their way instead of your way, find another shop that understands what you want, will listen, and do only the work you order.

It is best if you do the disassembly and assembly assuming you have the mechanical knowledge/skills/tools to do so. If you just give the complete engine to the machine shop you will be at their mercy, and the result may be anything from disappointing to a disaster. There are many horror stories in the archives.

Duke

[David C.]

Re: 57 250 HP Fulie Engine Rebuild

Joe,Duke

Thanks guy's, the info you provided is just what I was looking for!!

Dave

[Joe R.]

Re: 57 250 HP Fulie Engine Rebuild

Dave,

You're welcome! I should mention another tip. Before the machinist unleashes the beaver on your block, I would recommend posting a list of what machine work is recommended on here. Some shops have expensive machines to pay off. They will try to sell you unnecessary machine work. I know, hard to believe!

Joe

[Joe L.]

Re: 57 250 HP Fulie Engine Rebuild

I am restoring my 57 and before I get into rebuilding the engine I have a few questions.

1) If it requires boring, what pistons should I use?
2) Should the original rods be used? Rod bolts?
3) I want to keep it fairly stock with hydraulic lifters and cam. Who makes a replacement cam and lifters? Part Numbers??
4) Anything special about rebuilding the heads? - Seals and etc?
5) Higher pressure oil pump?
6) What Timing Chain manufacturer?
7) Gasket set supplier?

This car will never be raced or anything like that, so original horsepower will be fine!

Thanks

David-----

I would use Keith Black-Silvolite hypereutectic pistons. If you use KB 165 with your heads it will produce a compression ratio of about 9.4:1 which is very close to the original compression ratio. KB 166 will produce a compression ratio of about 10.6:1, but I would not go that high. It might work out ok, but it might not. It's not worth the risk.