215 Buick/Olds V8 & '64 Buick 300 Heads Combo Thoughts?

Huh, interesting. Thanks!

 

Just for kicks, here's what the Buick 300 rocker assemblies look like on the Olds 215 heads. Other than the rocker offset appearing correct, nothing else lines up. The stands need to be shortened 1/2"(?) to allow the rocker tips to contact the tops of the valve stems, and the stands' bolt holes would need to be be bored larger for the top Olds head bolt to pass through.

 

Advertised compression from GM was optimistic and usually about a 1/2 point lower actually. Measure the pin height of the flat top and the notched pistons, then use a calculator to figure true compression. You could check the cc's of the valve notches after you clean the carbon off. Probably 2-3cc.

 

Just to be clear, the pics of the engine with the valve notches in the pistons is not mine, so I only have the flat top 215 pistons with the tiny dimple on hand.

 

Just re-read the "Modifying GM's Aluminum V8's" article from 1961 when these engines were new, and they also noted that: 135hp on the dyno instead of the advertised 155, and 8.6:1 CR instead of the advertised 8.75:1 CR. Granted they poured mineral oil into the chamber through the spark plug hole to measure chamber CC, so maybe not the most accurate, but...Here's the article I'm referencing: https://www.seight.com/images/tech/magreps/1961hrm.pdf

It's interesting reading, as it appears they only has access to the 2-bbl Olds heads (maybe the 4-bbl head version was not available right off the bat in '61?) and the Buick 2-bbl version with the dished pistons. Most interesting to me is the final test, and although they did it with slightly modified (they seem to have tapered the quench pad a bit) 2-bbl heads-- which they fully admitted to not being an improvement over the stock heads--they still got 203 hp with all bolt on mods. The dual carb Edelbrock intake was a separate twin 2-bbl carb deal, so not sure how close or equivalent that'd be to the currently available Edelbrock 4-bbl manifold...I'm guessing the 4-bbl version is slightly better in most areas. Sounds like the typical mods to increase engine breathing on both the intake and exhaust sides are what gave the net increase in power, and headers seem to have helped quite a bit throughout the rpm range. Food for thought at least.

 

I decided to check the piston to deck clearance tonight, and found it was very close to the . 025" I saw mentioned by Dan Jones(?, I think?) at . 026" on my engine. My measurements are likely off a few thousandths, as I measured off a non-cleaned up block deck, but I managed to find clean spot or two. Piston tops were also not spotless, but I can use the fairly close number for now.

Speaking of those pistons, they have an interesting crown texture/surface finish. I would describe them as circumferential, as it doesn't appear to be a continuous spiral to me. One piston, with the number '4' stamped into the crown (first two images below) has much less of the surface texture still visible, while the other has no stamps I can make out, but the surface texture is much more pronounced.









Maybe the few I have been able to see clear images of have been carboned up, making the rings essentially disappear? It's not critical, as I'm still thinking an overbore will be needed, but I just found it interesting.

 

Those pistons have had the tops faced on a lathe, that is where the spiral pattern came from. Part of the manufacturing process.

As far as swapping the 300 heads onto the 215 block goes, there is one detail worth mentioning, and that is the difference in the upper corners of the block and heads which can cause a crankcase leak if not addressed. The 215 block has the corners going straight up where the iron blocks angle them inwards. Look at the head gaskets and it's obvious where the problem is.

Jim

 

Thanks for mentioning that difference, @Jim Blackwood. Here's a shot of both '63 215 and '64 300 blocks in that area:





It looks like there is enough material on the '64 300 aluminum heads to provide a good seal in that area. Here are some shots of the '64 300 head in place on the 215 block, highlighting the areas you mentioned:









The Rover gaskets @Jim Nichols recommended (and which I purchased) have straight upper tips, so I should be good there. The end seals of the valley pan/intake gasket should seal the small wedge that remains 'open' at the very top, I think.

 

Use a bit of RTV in the corners. I think the later Rover valley gasket is better than the 215 one. How does the 3.9 Rover head gasket look on the 300 head?

 

I ordered them a few days ago, so I will post a few pics once they arrive stateside.

I hadn't even thought about using the Rover valley gasket, so thanks for the heads up. I will look into it.

While inspecting all of the cam bearings with the block on my workbench, I discovered the front one has some...roughness,. Looks like some metal bits made it through:



The remaining bearings were much better, but, new cam going in anyway, so they'll be replaced.

I'm planning to use a modern, rear crank seal (two-piece, offset overlap Ford part is the suggested replacement, IIRC?), so this is the area which needs to be polished, correct?:



Do I need to do anything about the / / / grooves (assuming those are to provide steady oil to the old rope style seal), or does the new style seal not touch that area on the crank?

 

Get the TA grooved front cam bearing and in addition to the rear seal area polishing, look at the Damper in front. I think the 200 Ford six neoprene seal fits the rear, after trimming and offset 1/4" from the parting line. 80's Buick V6 front seal works in the front cover from the inside.

 

Yes, the hashmarks have got to go but just take enough to remove them. Should be less than .010"
I also checked the 300 heads and you are correct, those do have enough metal to seal the corners. It's going the other way that the problem comes up as Rover and TA did not close off the angle inside the corner. Hopefully TA will correct this in the next casting run. BTW TA carries both the front and rear seal as well as most other small parts. Large parts too for that matter. I like buying parts I know are going to fit. It's possible to fit a redi-sleeve to the damper but I suspect that might stretch the lip a bit more than is ideal.

The later Rover valley pan is much nicer, coated in neoprene. Not sure if it seals any better but it does look good. Cost about $40 last time I bought one though.

The Rover multilayer stainless steel exhaust gaskets are dope. Re-usable and last forever, and do not leak. Now more widely available at a lower cost (check ebay and amazon) but not properly sized for the 300 ports. I ported and re-beaded a set to use with my 340 that was equipped with alloy 300 heads and will do the same for my TA heads. Re-beading the ports requires a shaped wire and two plastic stamping pieces used in the hydraulic press (nylon is good). A little tricky to line up but does the trick quite nicely.

Jim

 

Was watching this YT video (again) last night, and noticed the lugs in the chambers of this '64 300 head are wedge/keystone shaped, not rounded (and smaller) like those in the 300 heads I have on hand. Just thought that was interesting, considering these were not in production for very long.





For comparison, the smaller, rounder lugs:

 

Here is one with square bumps, looks like iron heads:

 

I received the N.O.S. Trans-Dapt HE-25 cast aluminum bellhousing I purchased a few weeks ago, and it fits the 215 block very well. I will have to check the runout to determine if the center bore is off center, and order new dowel pins as needed. A test fit of the starter shows a some interference between the bell and starter nosecone, so I need to remove a small amount of material.

The IBR of the '88 T5 I have fits nicely into the bore, so now I just need to source a pivot stud, clutch fork, boot... Just glad to have this part in hand, as it will allow me to do some in-place mocking up to figure out where space us needed.

 

As requested... looks good, with one small overlap nearest the intake valve:

 

A few shots of the gasket resting on the block deck:







The only area where I could see the head gasket protruding a bit, on the exhaust side:

 

Looks good! I see it has the extra bolt holes for the older Rover and 215 heads.

 

With the steel shim gaskets, the surfaces have to be perfectly flat. You mentioned decking the block and milling the heads. I always spray them with Copper coat and retorque after cam break in.

 

Yes, I will make sure the machinist and I are on the same page with the thin steel shim head gasket being used. I should call him and get something set up soon. It would be good to know for sure the block and heads are sound and how much overbore will be necessary.

I think the chamber volume needs to be redced quite a bit since I'm using the 54cc '65 300 heads. The Egge flat top pistons only seem to be available with the valve clearance notches, which, if I use the Crower 50232 (.490 max lift), should work together fine. I don't really want to have a set of custom pistons made, especially a set without the notches to save 4 cc of volume. Not sure I want to get into flat head valves vs. dished to save 1.5cc per cylinder, but I suspect the valves I have are best replaced. This engine was run hard and didn't appear to have great oil supply up to the heads. We'll see.

I did read a few older posts/topics elsewhere about the Silv-o-lite Ford 170 I6 pistons...:https://www.mgexp.com/forum/mg-engi...baker-266-stroker-recipe-anyone-have.4496884/

...and I see they are still available, and not terribly expensive, either: https://www.summitracing.com/parts/uem-1119-020/make/ford

More of a back pocket option at this point, as the Egge pistons are probably fine for my needs, and the need to re-bore and bush the rod ends is only going to add more expense anyway.

I should find some checker/lightweight springs and check the valve to piston clearance as it sits now.