Hot Rods Let's talk Cadillac 331's, 365 and 390's

I would take that estimate with a grain of salt...

 

Nice article find. I'm interested in how they are doing the oiling for that RPM range...Interesting. In one of the last pictures there is an odd aluminum piece with x2 roughly -8An size tubes traveling the length of the block. What might that be - fuel related?

Also agree that 3000 HP is likely impossible considering the flow restriction / bottle neck that GMC 4-71 is going to make. I'll be surprised if it makes it to 8500 RPM too. But I've also never used Nitro.

 

I just wish there was a machine shop like that around here.

 

Interesting, what got my attention was the use of the sbc timing set. Wonder what modifications had to be done to get that to fit...

Also I rebuilt the oil pump for my 331 and tested the relief valve today. Using the original valve and spring with a .135 spacer gave me 40 psi and with a .270 spacer it opened at 60 psi. That's about what I wanted, but may play with it a bit more tomorrow.

 

I picked up on the timing set deal also. I’ve been wondering about that for a while.

 

About what I figured... too much trouble for this old guy to deal with.

 

I assumed this was due to the SBC crank snout change?

 

Yep. I am guessing so, since the chenged it for the 4-71.

 

Good article but 3000hp and a 8500 redline, yeh right oh. LOL!

 

Does anyone know the difference between an AC and non-AC equiped harmonic balancer for a '55 331?
I believe the AC equiped cars had a double pulley groove (?) but not sure why the balancer itself would be different? They are always listed seperatly with the suppliers.

 

I wanted to add a little info here to maybe help someone in the future. I bought a Schneider cam and valve springs part number 6710. To get the install height pressures correct they would have needed an average of .110- .125 worth of shim. The machine shop had a set of SBC retainers and tried them and because of the design they made up for .110 worth of height difference alone. Also the caddy keepers fit the Chevy retainer.
Stock 365 caddy retainer on the left and the SBC retainer on the right.

 

Anyone know of a source for good, made in USA lifters for the 49-55 331 engines? Just bought a set of Elgin lifters from evil bay and they are "Made in China"... I used Hylift-Johnson in my 390, but they don't make anything for the earlier engines.

 

I was planning on just using all SBC stuff on mine. I am going to changed the guides and cut them for a positive umbrella style seal. Those clunky Caddy retainers have to go. I just need to see what springs I can make fit. What was the diameter on your springs?

 

My guides are cut down 1/2” in height and also cut for umbrella seals. I don’t know for sure, but think they are a “z28” style spring, 1.26 OD

 

Also in that picture I posted those are the original style springs I used to brake the cam in, The ones I’m running have thicker wire and a flat damper spring.

 

Still looking for usable lifters! Sent the Chineseium Elgins back to the vendor. Have found a set of "lightly" used Perfect Circle lifters but am just as afraid of using them as I was of the new Elgins...

Was hoping to have this engine back in my roadster this week but am hung up due to the lifter issue.

 

Lightly used is still used. That's just as bad. No way I would try that. You have too much invested.

I'm sure you have done this already, but I sent an email to Caddy Daddy asking where his are manufactured.

 

And what was Caddy Daddy's answer? I honestly don't trust anything from Egge, Caddy Daddy, Kanter and the rest regarding their lifters anymore.

 

Nothing yet. I just sent it after reading your post.

 

I sent my lifters for my flatcad to Oregon cam and had them resurfaced I figured the original ones were better than any new ones you might give them a call they were real nice and done great work in a timely manner for a reasonable cost

 

Here is the response from Caddy Daddy.

Our manufacturers do not share with us actually where they are made once in a while we get NOS or NORS but if it’s not on our website now we don’t have it chances are they are made overseas because I don’t think that any manufacture in the US or Canada makes these.

 

Yeah, I think that's what I'm going to have to do. Sending e-mails regarding this to both Oregon and Delta now. I have a spare cam laying around that I'll have re-ground at the same time.

 

Question about 331, 365, and early 390 Cad oiling. Do we know if the oil pressure coming from the block to the external oil filter is still under decent / significant pressure? I need a pressurized engine oil source.. I'm thinking of using this as a supply prior to filtration to the TP oil filter.

- Alex

 

It's under sufficient pressure to make it hard to get the lid of a stock canister filter to seal, no matter how tight the center bolt is. I finally put a restrictor in the fitting at the oil gallery to reduce the pressure on the filter. ala flathead Ford...

 

Anyone have any luck finding main bearings in .010 or .020 for a 331 (he really needs .010). I have a friend that's looking for them and can only find .030 and doesn't want to grind a good crank that low, since the crank was ground to .010 already.

 

Thanks for this info. This is what I was hoping for.

 

what engine? They take different bearings. I have 331 .020 rods and mains. And a freshly ground crank

 

Yeah, I spaced....it's a 331.