odd ball cadillac 331-390 speed equipment

Technically not repoping, offy just started making them again a year or 3 ago.

 

when I was a dealer for Offy over 10 years ago, I would still get Nailhead log manifolds and other oddball stuff from them.They had them in the warehouse collecting dust.They told me they could make anything that was in there old catalog if they got a big enough initial order .

 

I have an oddball piece...it was bolted to a '52 Cad 331 full house stock car motor that I bought years ago....it was used as a belt idler/tensioner in place of the generator...looks like they made it out of an original generator front pulley, very well made even has a zerk fitting in it to grease it....

 

Do you have pics or info on the stock car motor? Pretty clever setup.

 

Im gonna have my set of 4x2 cast logs for the 331-365 avail again in a month... waiting on foundry right now ... will have 15 pairs ready for those interested

 

Wow it's even on a '49 engine!!

Now that would look cool on my 331 in my model a!!

 

I got the motor years ago from an old timer in St. Lois area...a friend of his and fellow stock car racer had passed away and he bought all the old equipment from the wife. He said there were all these small block Chevy's lined up and this one lone motor he wasn't even sure what it was...somebody had painted it Chevy orange years ago.
It was a neat motor with the factory cast iron dual quad manifold, Isky 5-cycle cam, Isky springs, adjustable rockers, etc....ported/matched intake and heads. It was .125 over with huge domes on the pistons (Jahns)...musta been like 12:1. Had an old chrome water pump, thermostat housing, pulleys, chrome harmonic balancer etc....Scheifer aluminum flyheel...they had balanced the pressure plate by welding on little pieces of threaded rod. Some of the work was slightly crude but somebody had put a lot of time and effort into this thing....I'll bet it really barked. Also had a little hydraulic slave cylinder on a home made bracket mounted to the side of the block to actuate the clutch...Offy Rocker covers...

that's about all I can rememeber....I just sold it about 6 months ago to a buddy up in Massachusettes who is going to try and get it running again....


>>>>...I just remembered one more interesting thing about it....when I pulled the oil pan it felt heavy ...almost like it was cast. It was coated with some sort of galvanize plating...not the rough crap you see today on the bolts at Home Depot, but like the old shiney trash cans with the smooth surface and a pattern in it that looks like big flakes. It was painted orange outside but you could clearly see it on the inside and where the paint was peeling....I had never seen a pan like this before.

 

If your buddy gets it running or would share pics. Id like to see them. Finding competition caddys is rare and this one sounds pretty neat.

 

will do...all this talk about it is making me wish I didn't sell it...!!

 

picked up a early cadi mallory magspark distributor and matching coil today.

jeff

 

Nice!

 

what carbs are those on the Nicson? I have a Nicson and need to add the carbs.

 

The last Offenhauser 3X2 for the early Cadillac to go ebay this sunday.

Sadly I will have to part with one of my all time favorite hot rod manifolds soon, but it was either this one or the injection set up so off to evilbay she goes to hopefully find someone with a hot rod that will use her as intended and not hang her on a wall.

A good friend of mine worked for Offenhauser in the early 80's and this manifold was the last of the old Cadillac stuff sitting on the shelf when he left, 1981.
Since then they have obviously been recasting the old lines but the 3X2 Cadillac manifold has never been reissued because according to him the pattern was lost long before he started there in the mid 70's.

 

I'm finally starting to get my 331 back together and ready for install in my 49 Mercury

The quick rundown:
-53 blocked bored to 4" using vintage jahhns pistons
- the block has been decked .120
-55 heads milled .050
-isky cam & springs
-smith brothers adjustable pushrods
- solid sbc lifters
-edelbrock tri carb intake topped w/ 97's and hellings air cleaners
- Hildebrandt vc's

Im using a 50 olds bell housing (so I can use mid mounts) and running a Lasalle shifted via a "King Shift" shifter.

I could really use a good performance distributor if anyone out there has one they'd come off of.
That's going to be the cherry a top my Cadillac powered shake

 

This Caddy porn is driving me bonkers! Keep it coming, I am like a 16 year old who finds a box of porno's! Cant,...stop,...looking,....

 

JJ, what kind of CR do you think you'll end up with?

 

Gonna be beautiful.

 

We ended up right at 10:1 if I remember correctly.
The stock CR was super low and was even lower than what the manufacturer claimed when calculated.
My good buddy and club member Shawn put the engine together for me (he's the most dialed engine builder I've ever met). We went back and forth on how much we wanted to build it and what we could get away with in a daily driver.
We finally decided we needed to get the compression up and opted to deck the block rather than offset grind the crank and get all sorts of carried away.
It took a whole lot of machine work, but it ultimately was the easiest path to good compression numbers and zero deck.

 

Thanks Dreddy!
The other JJ sent me a pic of a few of your chrome cad pieces the other day on the way back from the chrome shop/ chrome shed.
I need to do the same and get
A few pieces plated. Your stuff looked to have turned out pretty nice!
Same guy did my water pump..... Not so awesome... But cheap.

 

Why did the block need to be decked so far? Were the pistons right?

 

The pistons were the same hight as factory pistons with the same pin location just oversized. When assembled my pistons were .120 In the hole and my compression was going to be around 8:1.
At that point, I could either start lookin for a blower set up or deck the block. Decking my block was the cheapest way to higher compression.

 

They were rebuilt 20 years ago, I seem to remember that they are matched pair off of an El Dorado. I do not remember what kind of carbs but the tags that are screwed on to them gave the rebuilder all the info he needed.

 

Lovin this post...Picked up my 390 Caddy engine from our very own "Royalshifter" it will be replacing the Flathead in the 34 this Winter.

 

Went the wrecking yard last week and they recieved some early buicks with the small base 4bbls, so i was able to nab 2 rochestors 1 carter and 2 stromberg 4bbls. so i stuck the rochestors on my detroit racing intake.

JEFF

 

That's so awesome. I'm super excited!

 

The 331-390 Caddies have the pistons way too far down the hole for good performance.

http://racingarticles.com/article_racing-10.html

A quench distance of between .035 and .060 is considered optimal. If you set the pistons flush with the deck of the block, your quench distance becomes your compressed head gasket thickness.

It is much cheaper to deck the block than to order custom pistons that are taller.

 

You sure about that? The CR on the later motors is like 10:1. I know it's more than my skinny little tires can handle..

 

Yes, the chamber volume is smaller in the later cylinder head castings.

There is another thread on Caddy engine building where I posted the chamber volumes and what the results are from swapping different casting number heads:

http://www.jalopyjournal.com/forum/showthread.php?t=8282&page=2

 

That's awesome, I havent seen that yet. I have another motor I need to build too.

 

I haven't been inside a 390 to measure, but The 331's and 365's actual compression ratios were much lower than what the manufacturer advertised them to be.

The 390s have longer stroke than the 331's and 365's. Their stroke is 3.875 compared to the 3.625 stroke of the earlier engines.
That's probably where the 390 get it's 10:1 CR.
If anyone has the heads off a 390 I'd love to see how far in the hole those pistons are.... I'm guessing not very far