You guys with the 215 Buicks and Olds engines

[MECHANIST]

What do you do about the intake manifold gasket? Are new ones available somewhere? How about reusing one that looks good? Anyone have one std piston for an olds block I could get? I could use a distributor, complete or just the body.

[NixVegaGT]

Are you talking about the tin valley cover? I got an OEM stock replacement. I think they sell new ones for Rovers on RockAuto.com or the like. I gave a bunch of spare parts to one of my H-buddies up here in MN. Tony? You out there?

[Moderator]

The steel valley pans are still available from Fel-Pro. You should be able to get them locally through Carquest or NAPA... but possibly not the discount places.

Rover dealers offer a "composite" valley pan, which costs twice as much but which is reportedly much quieter. (I used Fel-Pro.)  

I keep my old Delco-Remy distributor as a spare, and I used a Mallory Unilite. A Pertronix conversion for the Declo would've been cheaper. I think the Rover versions came with different advance curves over the years. A little more useful info may possibly be here:
Rover distributor: http://www.britishv8.org/Articles/Curving-Rover-Dizzy.htm
Buick distributor:http://www.britishv8.org/Articles/Mechanical-Ign-Advance.htm

[BlownMGB-V8]

That Rover valley tin is the only thing I would consider using. Much better sealing properties, well worth the cost.

Jim

[Phillip G]

Machinist,

Bill Lunbom,

I just broke down an Olds 215 engine.

Bottom end looked like new - and probably standard, though I can't guarantee it.

I'm using the block and head and pan for mock-up work on the engine compartment of my ... B chassis to SCCA RV 8 project.

I would be happy to mail you several of the pistons and rods and rod ends - still together - at no charge.

Let me know.

Phillip G

[MECHANIST]

Phillip,
   
   I would be delighted to get 2 assemblies. I also need the set of the 8, 6" head bolts and a distributor.
   
   I can initiate payment with PayPal when you know the cost, if that is suitable.

   Yours truly,

   Bill Lunbom  at 25411 79th ave SW, Vashon, Wa, 98070
   206 463 3259

[Phillip G]

Bill,

I mailed to you today 2 Olds 215 rods and pistons from the engine I recently broke down for parts.

They are yours at no charge.  I hope they are of use in your project.

Do let me know that they have arrived and, later, that they have been of any use to you.  

The Olds 215 engine looked fine except for the cam.  Seems we always find flat cam lobes.

Phillip Leonard

[MECHANIST]

Philip,
I t was swell of you to send me those pistons but unfortunately they are not Olds pistons. You have a Buick block apparently. So I still need one or two pistons. Thank you for your generosity.

[Phillip G]

Bill,

Sorry about that.

Are the Olds pistons any different than the Buick pistons in the 215 blocks ?

Could you use 8 Buick pistons in the Olds block ?  If you can, I would trade you all 8 (6 more)  of the Buick pistons for your 7 Olds pistons - if that would help.

FYI - I am using the completely bare and light weight Olds block for a mock up of my Rover block while assembling the RV 8 chassis.

Again, I am sorry the Buick pistons will not work for you.

Phillip G

[Moderator]

Buick (and Rover) 215 pistons are "dished", wherease Olds 215 pistons are flat-topped with recesses into them for valve clearance. Here's an excerpt from an article that will run on our next issue. It explains the design differences further:

Buick and Olds differ drastically in combustion chamber design. Olds has a wedge type chamber, flat top pistons, and a port configuration which largely resembles that of the larger Olds engine. Buick has a machined chamber of comparatively small volume and dished pistons. The valves on the Olds are angled to line up with the slant roof of the combustion chamber. On the Buick, they are placed almost straight up, and the port design is of course closely akin to that of the larger Buick engine. Even valve cover placements are distinctively those of their larger engine counterparts.

Buick claims a more favorable surface to volume ratio at combustion time, together with a central plug location and very short flame travel through the major portion of the compressed air fuel mass. The squish area is distributed all around the piston and combustion chamber, creating a favorable turbulence. These dished pistons are quite reminiscent of those which enabled GM Research to run some very interesting tests at compression ratios ranging from 10:1 all the way to 25:1, or six points higher than with most diesels.

The use of a dished section makes compression changes quite simple, and we might add that the use of a flat olds piston in a Buick 215 would result in a compression ratio of 11:1. Where a dish is very deep and falls below the ring belt, some distortion can occur at operating temperatures and added heat is transferred to the piston. However, here the dish is so shallow as to have no practical effect.

[Phillip G]

Curtis,

Great info.

With that in mind, Bill Lunbom could use the Buick pistons in place of the Olds pistons. - living with a slightly higer compression ratio.

Curtis, how can these Buick cast pistons hold up to the extreme compression ratio (25 to 1) like a diesel and not fail in blowing out at the top of the piston ?  I thought that was why forged pistons were necessary.

I love this stuff.

Phillip G

[bplus]

Bill, I have a set of olds pistons. I've got to go
out of town on business tomorrow. Please send
me a PM with your contact info. We can coordinate
delivery when I get back in about a week.

Tracy

[castlesid]

Alternatively you could use the Buick pistons with composite head gaskets to bring the compression ratio down to a resonable level.

D&D would have what you need.

kevin.