BritishV8 Forum

General Category => Engine, Transmission, & Rear Axle assy. => Topic started by: DragNut on August 20, 2015, 05:34:43 PM

Title: Oldsmobile 215 Engine
Post by: DragNut on August 20, 2015, 05:34:43 PM
Oldsmobile 215 engine.....I bought this from a machine shop in Kansas with the intention of using it in my MGB. I was told the engine has been completely rebuilt, the compression test has 100 psi in all cylinders.
Title: Re: Oldsmobile 215 Engine
Post by: DragNut on August 20, 2015, 05:35:25 PM
mgbengine057.jpg
Title: Re: Oldsmobile 215 Engine
Post by: DragNut on August 20, 2015, 05:38:31 PM
mgbengine063.jpg
Title: Re: Oldsmobile 215 Engine
Post by: BlownMGB-V8 on August 20, 2015, 10:33:58 PM
That's a poor compression number. For a fresh rebuild on an Olds 215 that would signify the use of low compression Buick pistons with the 2bbl Olds heads, resulting in a CR of about 6-1/2:1, and it'll run that way, I had one that I used for years as a spare or "mule" engine whenever the good motor was down for repairs. Figure on around 135 HP and poor fuel mileage. Unless you misstated the compression figure.

Jim
Title: Re: Oldsmobile 215 Engine
Post by: DragNut on August 21, 2015, 04:41:51 AM
These are numbers I was told from the machine shop where it came from...I haven't done a test myself...
Title: Re: Oldsmobile 215 Engine
Post by: BlownMGB-V8 on August 21, 2015, 09:25:56 AM
Very odd. You might want to do that test. I wouldn't think a machine shop would intentionally do that build. The one I had was built by a buddy even after I did my best to talk him out of it. How I ended up with it is sort of a long story, but I did get my money's worth out of that engine.

Jim
Title: Re: Oldsmobile 215 Engine
Post by: MGBV8 on August 21, 2015, 09:26:13 AM
Looks like a Buick ID number on that block.
Title: Re: Oldsmobile 215 Engine
Post by: DragNut on August 21, 2015, 04:48:54 PM
Yeah...It wouldn't make sense...Its a "HI" block...Im going to do a compression test myself....
Title: Re: Oldsmobile 215 Engine
Post by: DragNut on August 21, 2015, 04:49:57 PM
Carl....Im no expert but I don't think Olds heads can bolt to a Buick block...different bolt pattern....No?
Title: Re: Oldsmobile 215 Engine
Post by: Moderator on August 21, 2015, 10:25:07 PM
A machine shop can make it work. Olds blocks simply have eight extra holes drilled and tapped.
Title: Re: Oldsmobile 215 Engine
Post by: Todd McCreary on August 21, 2015, 10:46:47 PM
Buick cast iron small blocks and later Rover engines are 4 head bolts per cylinder.

Buick/Pontiac 215s and early Rovers are 5 bolts per cylinder.  Rover builders recommend not using the 5th bolt in order to get more equal clamping, which alleviates head gasket problems on the intake ( no bolt ) side.

Olds 215s are 6 bolts per cylinder.  

The dimensions on the '4 bolts per cylinder' from line 1 are shared by all members of the Buick small block family, so you can always use any head on any block, you might just be limited to fewer bolts than the head is drilled for.


If the unused holes in the block go into the water jacket, they need to be plugged.

http://www.britishv8.org/Articles/Buick-Aluminum-Engine.htm

fig 19 shows an Olds style block, fig 27 shows a Buick style.
Title: Re: Oldsmobile 215 Engine
Post by: DragNut on August 22, 2015, 09:12:22 AM
Looks to me that its 5 bolts per cylinder
block017.jpg
Title: Re: Oldsmobile 215 Engine
Post by: DragNut on August 22, 2015, 09:15:12 AM
Also has these numbers stamped on the side of the block
block011.jpg
Title: Re: Oldsmobile 215 Engine
Post by: DragNut on August 22, 2015, 09:27:48 AM
So  now after some more investigating  im thinking this is a Buick High compression block , but the heads are still confusing...I thought Olds heads had six bolts per cylinder...im seeing 5.....
Title: Re: Oldsmobile 215 Engine
Post by: Moderator on August 22, 2015, 02:27:51 PM
"Looks to me that its 5 bolts per cylinder. "  Nope! The sixth bolt (per cylinder) is longer and comes right up through the rocker-supporting pedestal. "I'm thinking this is a Buick High compression block."  The block doesn't directly effect compression ratio. To provide various compression ratios, Buick used pistons with varying volume dishes. Oldsmobile took a different approach: they didn't supply a variety of piston types, but instead Olds varied cylinder head combustion chamber volume.

---

I'm surprised no one has commented about the first photo in the thread. At some point, someone purchased Offenhauser valve covers, an Offenhauser intake manifold, and I think a Mallory distributor. (Verify this, and determine which one.) They were spending money freely. There's no telling what parts they put inside the engine. And what machine work. They may have ported the cylinder heads. I think you'll have to take this engine all the way apart and inspect carefully to know what you have.
Title: Re: Oldsmobile 215 Engine
Post by: DragNut on August 22, 2015, 02:49:19 PM
Oh...its hidden!! Yup....That's a Mallory....
Title: Re: Oldsmobile 215 Engine
Post by: Todd McCreary on August 22, 2015, 06:31:35 PM
They were spending money freely.


They weren't spending money freely on the the oil filter.  That's a junk Fram unit.

I'd get a Napa Gold,  AC-Delco or Wix on that before I fired it up.  You also want to prime the engine, either with a pump priming tool or by spinning it on the starter after taking all spark plugs out.



Also has these numbers stamped on the side of the block


Being nitpicky, but those are casting numbers.  Stampings are the "HI" numbers you posted earlier.

Which, by the by, "HI" should indicate a 1962 hi compression Buick long block assembly.

The block casting number also shows up in the Buick lists:
http://www.buicks.net/shop/reference/smallblock_casting_numbers.html


But I agree with Curtis, given how much money DID get spent on this engine, you really need to tear down to see what you have.

First step would be to do your own compression test though.

Second, if you continue to get those junk 100psi numbers, would be to hook the compression test plug up to an air compressor and see if you can hear air leaks in the intake/exhaust.  This will tell you if the valves are sealing or not.   If they really did put Olds heads on a Buick block, the rocker geometry is different and they may have used the wrong set of pushrods.
Title: Re: Oldsmobile 215 Engine
Post by: BlownMGB-V8 on August 23, 2015, 08:57:17 AM
There is a serious problem with putting Olds heads on a Buick block. Now I'm not by any means saying that it can't be made to work, but my understanding is that the Buick deck does not have the internal bosses cast in place to allow proper drilling and tapping of head bolts in the top row. That's what I've always heard, but it's been so long since I looked carefully at one that I wouldn't want to go by memory on this, but would ask someone with a bare Buick block to confirm it.

But if indeed that is the case, it means the threaded hole those pedestal bolts go into is only something like 5/16" thick. That MAY be enough to anchor the rocker pedestals but it certainly will not secure the head bolts and since on this engine the rocker pedestal bolts are also head bolts they will never accept full torque. Perhaps the builder torqued the top and bottom rows to a lower figure.

In any case, despite the money spent on externals, given the head mismatch I would really have to question the internal assembly. Sorry to say that, and first step would be to verify the bolt boss question, but based on what I think I know them's the facts.

Jim
Title: Re: Oldsmobile 215 Engine
Post by: Todd McCreary on August 23, 2015, 11:29:24 AM
but my understanding is that the Buick deck does not have the internal bosses cast in place to allow proper drilling and tapping of head bolts in the top row.


while this is true of pretty much every pic of a Buick 215 block i've ever seen, what would prevent you from counter sinking a nut into the bottom side of the head?

after all, if 4 bolts / cyl is all that's really needed, especially in a non-boosted application, all you really want to do is hold the rocker shaft down with the top row of bolts.
Title: Re: Oldsmobile 215 Engine
Post by: MGBV8 on August 23, 2015, 04:14:34 PM
It looks to me like a Buick block could easily be drilled & tapped to match the Olds block.

Buick 215:

(http://www.britishv8.org/MG/MikeAlexander2/MikeAlexander-MG-MGB-32.jpg)

Olds 215

(http://www.mgexp.com/phile/40/174195/clean_engine.JPG)

I'm not convinced that they are not the exact same castings.
Title: Re: Oldsmobile 215 Engine
Post by: DragNut on August 23, 2015, 05:55:24 PM
Just looking at this picture of the block...The lower bosses at the bottom head mounting holes are the exact same shape as my block...also the block seems to have Buick numbers...HII6705...and the heads are Olds heads...3 valve cover bolts on the bottom and 2 on the top....
Title: Re: Oldsmobile 215 Engine
Post by: BlownMGB-V8 on August 23, 2015, 09:42:32 PM
Yeah, it sure looks to me like in that picture there would be metal where you'd need it.

Jim
Title: Re: Oldsmobile 215 Engine
Post by: MGBV8 on August 24, 2015, 12:01:36 PM
Here's a pic of the earliest Rover V8, the P5. Rover eliminated the bosses for the extra head bolt from the very beginning.

Now we have another quick spotters guide to differentiate a Rover V8 block from a GM.

RoverP5engine.JPG
Title: Re: Oldsmobile 215 Engine
Post by: Todd McCreary on August 27, 2015, 08:29:20 PM
Yeah, and Buick also got rid of the intake side bosses when they went to the cast iron 300 ( I've got one ) as well ... the sorry bastards.

This page has a good overview of the various heads.  Say thanks to Jimbo for diggin it up for me.

http://www.roversd1.nl/sd1web/capacity3.html
Title: Re: Oldsmobile 215 Engine
Post by: MGBV8 on October 07, 2015, 10:11:57 AM
Okay, it can be done cause it has been done. here is a 1961 Buick 215 that has been drilled & tapped for the 6th head bolt.

http://www.mgexp.com/phorum/read.php?40,3099017

Curtis,

I found a couple of website with more Buick 215 id. info.

http://www.buicks.net/shop/reference/smallblock_casting_numbers.html

http://transmissionadapters.com/buick_casting_number_id_chart.htm
Title: Re: Oldsmobile 215 Engine
Post by: BlownMGB-V8 on October 07, 2015, 11:18:50 AM
Ah, but the real question: Are the newly tapped holes in the deck blind holes? Or are they open to the water jacket?

Jim
Title: Re: Oldsmobile 215 Engine
Post by: MGBV8 on October 08, 2015, 01:03:41 AM
He says blind.
Title: Re: Oldsmobile 215 Engine
Post by: 88v8 on October 08, 2015, 04:59:59 AM
Just to throw in a thought - could it be that this was built for supercharging? Hence the low cr.
The cam spec might give a clue.

Ivor
Title: Re: Oldsmobile 215 Engine
Post by: pcmenten on October 08, 2015, 06:35:52 PM
Is it possible that this was done at the factory due to a shortage of Olds blocks?

As I recall, the flywheels were slightly different from the Olds to the Buick. Looking at the balancing pins pressed into the flywheel might help clarify which factory this came from. Likewise, Buick varied its pistons, so if there's a dished piston under the heads, that will imply a Buick short block.
Title: Re: Oldsmobile 215 Engine
Post by: joe_padavano on October 10, 2015, 10:46:33 AM
"Is it possible that this was done at the factory due to a shortage of Olds blocks?

As I recall, the flywheels were slightly different from the Olds to the Buick. Looking at the balancing pins pressed into the flywheel might help clarify which factory this came from. Likewise, Buick varied its pistons, so if there's a dished piston under the heads, that will imply a Buick short block."

The block castings are dimensionally the same between Olds and Buick 215s.  The only difference is whether or not the sixth bolt holes were drilled and tapped.  

The Olds and Buick FLEXPLATES are different due to the differences between the RH5 trans and the Dynaflow.  The Olds RH5 used a fluid coupling internal to the trans, not a conventional torque converter.  The front of the RH5 simply has a splined input shaft, similar to that on a manual trans.  The Olds "flexplate" really looks like an MT flywheel with a separate hub plate with springs that looks like the center of a clutch disk.  This is to make up for the lack of a torque converter on the RH5.

The Buick and Olds MT flywheels are the same, except that Buick used a flywheel with an additional inertia ring outboard of the clutch area to increase rotational inertia on certain heavier models (like wagons) to make for a smoother clutch engagement from a stop.  The Buick and Olds flywheels can be swapped.
Title: Re: Oldsmobile 215 Engine
Post by: Todd McCreary on October 17, 2015, 12:48:17 AM
Do you take apprentices, Joe?

You're like an encyclopedia.
Title: Re: Oldsmobile 215 Engine
Post by: quietone on November 28, 2015, 05:11:00 PM
Olds and Buick castings are identical is my understanding, only the machine work is different.
Title: Re: Oldsmobile 215 Engine
Post by: BlownMGB-V8 on November 29, 2015, 11:20:23 AM
It seems this could be true. The outline of the lug is there and it would make sense to eliminate it if you were eliminating the metal the stud screws into. So I'm inclined to agree that the old statements that there was no support under the deck for the top row of studs may have been an uninformed guess by someone who was not an engineer.

Still just a theory until someone drills one out though.

Jim
Title: Re: Oldsmobile 215 Engine
Post by: MGBV8 on November 29, 2015, 07:39:52 PM
QuoteOlds and Buick castings are identical is my understanding, only the machine work is different.

That and the casting numbers.  ;)