Engine and Transmission Tech

I have ID my Buick 215 block as a high compression engine ..it has the "HI" stamp, but the heads have an "SO" stamp??? Can anyone help me ID these heads?

The important thing for the head is the casting number, which you probably have to pull the valve cover to see, should be 7 digits.

The problem with that being that 215 casting info is very scarce.

If they're Buick 215 heads, the combustion cavities are ~37cc. Buick got different compression ratios by varying piston dish.

I was told that they are buick heads....I am going to pull a valve cover today...the stamp on the side is SO28795

With a little practice you'll soon be able to tell Buick 215 heads from Rover heads at a glance. The exterior surfaces of Buick 215 heads are very smooth like a die casting, whereas the exterior surfaces of Rover heads have the slightly pebbled texture of sand castings. Accessory bosses are quite different too. In the photo below you'll note that there are no accessory bosses on the front surface of the passenger-side cylinder head. It's a Buick 215 head. If it were a Rover head, it would have bosses/holes there (reference). And, Buick/Rover heads can be differentiated from Oldsmobile 215 heads at twenty feet by the shape/style of their valve covers. The top surface of Buick/Rover valve covers are parallel to the road whereas the top surfaces of Olds heads are parallel to the head gaskets. If the valve covers are removed, count head bolts: 5/cylinder (14/head) for Buick 215 and all Rovers except 4.0/4.6, versus 6/cylinder (17/head) for Olds.

Buick 215:

(note: this engine was/is fitted with Buick V6 timing cover and oil pump.)

Ok...So this engine probably has Olds heads then...

Heres a better picture

Yes, that is definitely an Olds. They used different heads for different compression ratios rather than changing the pistons. There are three heads that were available, low compression on the 2bbl engines, high compression on the 4bbl engines and high compression on the Jetfire turbo engines. The 4bbl and Jetfire heads were essentially the same except for some minor chamber differences. With the engine assembled, probably the best test is to run a compression check, as the pistons may not be original.

Jim

Offenhauser valve covers and intake manifold... very handsome!

It would be an Olds block as well, unless someone went to a great deal of trouble. The numbers should identify it I'd think.

Jim

Thank You for the info Jim..The numbers on the block are...CFD-PMJO 1193724. I have been looking on the web trying to ID this block but no success yet. Theres also some other numbers stamped on the upper cylinder bank...HII6705. I got this from a machine shop in Kansas and he didn't know much about the engine...only that he thought it was rebuilt and never run. Any idea what the compression reading should be? Also is there any rebuild manuals out there I can get for this engine?

Another identifying feature - Olds valve covers have 5 retaining bolts (2 on the top and 3 for the bottom). Buick has 4 retaining bolts (2 top and 2 bottom.)



Edited 1 time(s). Last edit at 04/13/2015 12:38PM by ex-tyke.

Run a compression test and divide the result by atmospheric pressure to get your CR. So 160 psi is going to be real close to 10:1.

Jim

The numbers on the block are...CFD-PMJO 1193724. ... HII6705

On the Buick side, the 'HI' engine code would be the high output 1962 engine. Not sure if that still applies on the Olds side.


If you pull this apart, could you make a point to write down all the stamping and major part casting numbers that you find? Information for all of these early Buick/Olds engines is extremely sketchy.


We'd be looking for these casting nums:
block
heads ( probably under valve covers )
intake
R and L exhaust

The stamping numbers would be useful to fine tune the date and original application. Assuming that the block didn't get decked.



Posted By: ex-tyke Date: April 13, 2015 10:17AM
Olds valve covers have 5 retaining bolts (2 on the top and 3 for the bottom).

I dunno, mang. I'm not seeing that middle valve cover bolt for the bottom rail.



[442.com]

They do not. We need a pic of those block #s.

There is 3 mounting studs on the bottom of the valve covers....just hard to see in this picture...Is there any type of rebuild manual for these engines?

You can find old Motor's and Chilton's manuals in some public libraries still. The usual V8 guidelines apply. There really is only one special provision, pay particular attention to holding minimum bearing clearances and perform all the recommended oiling mods (a search should bring up a lot of posts on that). Studs for the heads and crank will add greatly to the reliability.

Jim

Buick/Olds/Pontiac Engine Codes:

[www.britishv8.org]

More on Olds:

[oldsjetfire.com]

Thanks Jim...

Original Oldsmobile service manuals are easy to find and cheap to buy on eBay. Mine looks like this one:
1961 Oldsmobile Service Manual for $29. How useful is it? I've looked up torque specs. Beyond that, these little engines aren't really all that exotic. A how-to-rebuild-small-block-Chevy book wouldn't steer you too wrong on general service techniques. Use anti-seize. Don't run without anti-freeze. Remove your distributor and use a drill motor to spin your oil pump until it builds pressure before you start the engine for the first time.

If you haven't already, our article archive has some good articles on these engines. Search through it. Here's a fun example: There's Soupability in GM's Aluminum V8's and here's a more generally useful one: MGB GT V8 Technical and Service Notes. (MGB GT V8 used a Rover 3.5, so torque specs are similar except one or two places... rocker shaft pedestal bolts come to mind.)

To really know what's inside your engine, you're going to have to take it apart. It's been rebuilt, so it almost certainly doesn't have original-size pistons or bearings. I'd bet it has an aftermarket camshaft. The heads may have been reworked, shaved, etc. It might have any combination of other parts. Serial numbers may not accurately tell you its compression ratio, or much else for that matter. But does it matter? You haven't really described what you hope to do with it. Maybe you should just relax, install it, and see how it runs.



Edited 1 time(s). Last edit at 04/15/2015 10:08PM by Moderator.