327 Engine Rebuild - need advice

[Mark P.]

I am planning a to build a stock long block 1965 300HP 327 and could sure use some advice for a vendor to source my parts. I want a vendor that can recommend the right parts but don't want to overdo it too much. Can Summit give this kind of advice ?

For my 283 build I went with Eagle SIR I beam rods, a Cloyes timing chain and gear, ARP head and main cap bolts and a Melling 10553 oil pump. Is this still a good choice ?

Any cam recommendations ? Need a manufacturer and part number.

The block has no main caps. Any good aftermarket caps I should buy ? Should I go with aluminum or steel ? Should I machine for 4 bolt mains ?

Should I go with the thin Felpro head gasket sealed with coppercoat to maintain compression or just use the standard gasket ?

I am starting with a block without main caps, 2 heads and a crank. I am building a car to drive but still trying to to get to a chapter Top Flight level. I have correct valve covers, timing chain cover, oil pan, manifolds, carbs, etc. from my other engine which has been through judging.

Thanks,

Mark

[Richard G.]

Re: 327 Engine Rebuild - need advice

IMHO Their is no need to go with 4 bolt mains. However, without the original caps the block will require a line bore.
The eagle rods are a good choice. Migrating from stock will also require a balance.
Is this project to look stock or is it a Matching Numbers Build?

[Mark P.]

[Duke W.]

Re: 327 Engine Rebuild - need advice

Eagle SIR 5700 press fit pin rods are a good choice as is the KB156 piston, and target a true CR of about 10:1. Beyond that you can buy OE replacement parts from NAPA or any other source that offers Sealed Power (Federal Mogul) OE replacement parts. Simply go to napaonline.com, input the vehicle data and pick your parts. Use the OE replacement truck roller chain (manufactured by Cloyes). As far as the oil pump is concerned, it's likely reuseable unless it had injected debris. It's easy to disassemble and inspect. No Melling off-the-shelf oil pump will have the correct pressure relief spring, but it you decide to buy new you can use the old spring or buy a new one from GM, which is still available from GMPD.

If you are interested in "more power" and useable revs, and are willing to spend the time/funds to massage the heads, consider the McCagh Special cam as discussed in the "Tale of Two Camshafts" article (easy Web search), and also the Compression Ratio Explained article co-authored by me and John McRae.

The quality of the final product will be directly proportional to the quality of planning that goes into the project.

Duke

[Mark P.]

Re: 327 Engine Rebuild - need advice

Thank you Richard and Duke. I'll start researching the parts I need and planning the build. Will try to maintain the compression ratio based on Duke's article.

[Bob W.]

Re: 327 Engine Rebuild - need advice

Mark, The GM part number for the oil pump spring Duke spoke about is 3814903.

[Gene M.]

Re: 327 Engine Rebuild - need advice

If you don’t have the main caps you will need a special timing chain. If this is not the original block that came in the car it’s not worth the trouble to rebuild it. Find a good block with the original caps.

Use the original GM oil pump or the pressure will not be right. Also stay away from any goofy cam and use the one that belongs in it. A bit of head porting and clean up with good quality one piece valves is all this little engine will need.

[Mark P.]

Re: 327 Engine Rebuild - need advice

Gene - Thanks for raising this issue as I was not aware how challenging this is. After talking to a few rebuilders I can now understand what you mean. I think I found a correct block that works even better for my car for about the price I was going to pay for the line bore and replacement caps.

I also bought a GM NOS oil pump.



Mark

[Troy P.]

Re: 327 Engine Rebuild - need advice

Align boring is always a good idea even with original caps. Balancing too of course.

I may be stupid but I always jump to the max overbore to increase the displacement. I figure I'll drive the car so little that it will never need a rebuild again.

[Gene M.]

Re: 327 Engine Rebuild - need advice

Align boring is always a good idea even with original caps. Balancing too of course.

I may be stupid but I always jump to the max overbore to increase the displacement. I figure I'll drive the car so little that it will never need a rebuild again.

None of that is necessary for a street driven engine other than rebalance.

[Craig S.]

Re: 327 Engine Rebuild - need advice

If you are striving to PV your car.......you will want a cam grind like stock. They will listen to the engine in a PV for any cam modifications.......

[Joe L.]

Re: 327 Engine Rebuild - need advice

Gene - Thanks for raising this issue as I was not aware how challenging this is. After talking to a few rebuilders I can now understand what you mean. I think I found a correct block that works even better for my car for about the price I was going to pay for the line bore and replacement caps.

I also bought a GM NOS oil pump.



Mark

Mark------


Does the pump body and cover have GM casting numbers on them?

[Mark E.]

Re: 327 Engine Rebuild - need advice

Align boring is always a good idea even with original caps. Balancing too of course.

I may be stupid but I always jump to the max overbore to increase the displacement. I figure I'll drive the car so little that it will never need a rebuild again.

Maximum overbore in a 327 is what? .060"?
This buys you 10 cu inches in a 327. Will that make a noticeable difference in performance?

Downsides include machining cost, greater vulnerability to overheating, less life in the block, fewer choices for rings.

I'd choose the minimum honing/boring needed to clean up the cylinders.

[Duke W.]

Re: 327 Engine Rebuild - need advice

Align boring is always a good idea even with original caps. Balancing too of course.

.

NOT TRUE! The first thing to do is measure alignment with a machinist's bar and .0015" feeler gage... same with the head surfaces. Contrary to popular believe most blocks DO NO need to be align bored, and this operation will raise the crankshaft centerline, which affects timing chain geometry and deck clearance. Head surface flatness should be measured with the same tools, and if they are flat, do not surface.

Many machine shops with align bore, deck the block, and surface the heads without taking any measurements. It's a revenue generator. Owners must vigorously manage the machine shop, and INSIST that metal be removed only if ABSOLUTELY NECESSARY!

Duke

[Troy P.]

Re: 327 Engine Rebuild - need advice

Good advice. I'm pretty sure you are not a fan of my approach to bore out to the max allowable if boring is needed, even in a car rarely driven.