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

Hi all, bit of a lurker here, but I have read many topics covering the 215 and 300 V8s here, though definitely not all of them.

I have a '52 Nash Rambler wagon, so roughly 2500lbs stock. I am looking for perky, enjoyable street performance, but do not need nor want 300hp. 5,000-ish redline and a broader torque curve would be preferable over something peaky at the 4,500+ rpm range-- so mid range torque in line with a 'streetable' engine. I'd prefer not to have to run premium, but it wouldn't be a deal killer if it was required. I'm thinking 9.5:1 max compression ratio to not need to run premium fuel?

Back story: I picked up a '73/'74 4-bbl Buick 350 for $100, as it was "previously rebuilt" and turned over freely. Needing a replacement oil pan, I subsequently picked up a 2-bbl '65 Buick 300 with a good oil pan, then went down the 215/300/350 rabbit hole. A $100 '64 300 with the aluminum heads popped up for $100, so I picked that up, too, because it's good to have options.

Most recently, I picked up a '63 Olds 215 (4-bbl block with flat top pistons w/Olds 2-bbl heads), and while I understand the limitations of the aluminum block (thank to many warnings from @Jim Blackwood 's posts), I am comfortable proceeding with the Olds 215 block. The weight savings of the Al block, heads, and intake (75.2lbs weight savings for the Al heads and intake vs. cast iron for the '64 vs. '65 300 engines) is a major factor for me, especially being on the front half of the vehicle. While this car will never see track time, weight balance and savings are important in my experience.

I am well-versed in the similarities and differences between the Buick and Olds 215 V8s, and completely went through the '65 cast iron heads (disassembled and cleaned every hydraulic lifter, cleaned valves, re-lapped them, etc.), so I feel I have a good idea of how both the 215 and 300 valvetrains work...and their weak points, especially the aluminum Buick 300 rocker arms.

Getting around to the post title subject, my 215 Olds block will need to head off to the machine shop, and odds are good it needs an overbore, as there as some lights scratches in some of the bores, and one deeper one in cylinder bore #2. I see Egge offers a piston set for various overbores, so at least there is an option to work with the stock flat-top Olds pistons. I do not plan to used the 300 crank to create a stroker build at this point, though that is a back-pocket option if needed.

The aluminum '64 300 heads I have need a full rebuild, as the valves were sloppy in the guides, and one stem tip is so mushroomed/flared it will not allow the valve to slide out of the guide bore. This engine was not well cared for, but I did fully clean them up, and saw no cracks or other obvious damage, so I feel they are very good cores.

The stock Olds 215 2-bbl heads have roughly the same (51cc) vs the '64 Buick 300 (54 cc, both volumes taken from this article: https://www.teambuick.com/reference/library/affordable_aluminum_v-8.php ), so the larger valves and intake and exhaust ports would be the main benefits of using the Buick 300 heads on the Olds 215 block. However, not being well-versed in quench and head chamber size/shape/contour in relation to cylinder size/bore, is the combo of Buick 300 heads, with their 3.750" 'bore' vs the 215's 3.500" bore (well, could be 3.530 assuming a .030" overbore) a bad idea? I have mounted a 300 head to the 215 block and taken pics looking up into the chamber, and there is very, very little quench area (well, flat pad area is maybe a better description?) with that combo. I have done some online research regarding quench and what is desirable, but I haven't seen any mention of this particular situation where there is a mismatch in the block and cylinder head bore sizes, so to speak. I understand some decking of the block and/or slight shaving of the heads (though IIRC from reading previous threads there isn't a lot of material which can be safely removed from the head surface) may be necessary to boost the compression a bit-- I think I got mid 8.-ish using the online calculator with a .040 head gasket thickness. Again, I have no desire to run a 11.25:1 compression ratio, so I am thinking around 9.0-9.5 would still be a reasonable, streetable ratio to run on non-premium fuel.

I have read and saved most of the vintage 215 articles posted on the V8Buick 'site and elsewhere ("There's Soupability...", etc), but feel free to add any which you think might be helpful, please.

Sorry for the long winded post, but feel free to add critiques, corrections, and comments as necessary. I'm not expert, but I think I have a fairly good idea of my want with this build.

*Edit* Here are a few pics of what I'm working with:

'64 Buick 300 head on Olds 215 block, looking up into cylinder:



'64 Buick 300 vs '63 Olds 215 head intake port comparison:






Head chamber comparison, Olds first:








Olds 215 test fit in engine bay:

 

Cool project. I have nothing to add as I'm not well-versed in anything but the 350. It will a conversation piece at cruise-ins for sure.

If you want more torque and run on 87 octane without issues, the SBB 350 would be the way to go if for no other reason than transmission choices. It will be 135 CID larger and at least that in HP and torque over the 215 in stock form. The machine work on any engine is going to be about the same and a Buick 350 is pretty light though not 215 light.

 

Most machine shops do not press out the valve guides from the aluminum heads for fear of gulling the aluminum around the guide. They enlarge the hole in the old guide and put a new guide inside it.Do you think you'll be able to port match the 215 manifold to the 300 heads? It seems like flat top pistons, zero clearanced with that chamber size would yield a conpression ratio aroind 11:1+.

 

I honestly do not need a lot of torque, as I'm looking at 2600 lbs vehicle weight or so, 3.55 rear gear ratio, T5 with a 2.95 first gear (I think), etc. I did a fairly deep five on he Buick 350 early on, and while not quite as light as generally mentioned, it's still a great option for a traditional V8-- just not for me and this project. The cast iron 4-bbl 350 intake manifold is an absolute BEAST, too...73 pounds or so.

I didn't mention it, but I already acquired a BOP bellhousing and WC T5 5-speed, so although I'll now need a different bellhousing for the 215, the T5 will still be used. It was out of an '89 Camaro V8 with a 2.95 first gear and .63 O/D 5th gear, IIRC.

I have a good machinist I've had do (excellent) work for me before, so I think I am good there, whatever may be required. Good to get more info, though, thank you.

The online compression calculator I used is here: http://www.csgnetwork.com/compcalc.html

Just using it again now I got 8.16:1, with the 54cc '64 Buick head chamber size, the 215 head gasket bore size (which might need to be the 300 bore size? Not sure on that one), and a head gasket thickness of .0450". I think the flat top pistons are .025" below the deck surface, but I used zero, so that'd increase chamber volume a bit, too.




If I use the '64 Buick 300 heads, I could use the Buick head gaskets (instead of Olds-specific), but not sure if I can use the 215 head gasket with the 300 heads. I guess I need to take a closer look and the 300 head's chamber shape and size and the rough "diameter' of the chamber. Shaving a bot off the head surface would theoretically decrease that max diameter at the mating surface, but that mating area between the 300 head and 215 block concerns me a bit. Head gasket cylinder bores are stated as 3.620" for the 215 and 3.937" for the 300, both Fel-Pro.

I can do some port matching between the 215 intake manifold ports and 300 head intake ports as needed. I do not have 215 intake yet, and did not want to commit to one just yet, as the Edlebrock (I think that's the only commonly available aftermarket 215 intake now? Offy is long OOP, I think...) intake might end up being a better option than the factory intake. The head intake port size difference between the '64 300 and '63 Olds 215 heads was not as great as I initially expected before I did the side by side comparison-- nothing like the much taller Buick 350 ports, at least.

Here is a post on the British V8 forum from which I gleaned some info (and the compression ratio calculator link): http://forum.britishv8.org/read.php?2,54758

"I used 300 heads years ago on a 215. I used the hi compression pistons, and 8.5 to 9 to 1 is about right. You could use a compression calculator and figure 39 cc for 215 chamber vs 54 cc for the 300. .020 for steel shim vs .040 for composition head gasket. I would deck the block .030 and skim the heads to make sure they are flat to regain some compression."

Cylinder head volumes found here: https://www.teambuick.com/reference/library/affordable_aluminum_v-8.php

CYLINDER HEAD VOLUMES
'61-'63 Buick 215.....37cc | '64 Buick 300.....54cc | Olds 2-barrel....51cc | Olds 4-barrel.....38cc

The two heads I have on hand are very close in volume, so I used the 54cc for the compression ratio calculator above. Using the .025" piston deck clearance number drops the CR to 7.73 with the '64 heads...not cool.

I appreciate the responses so far, thanks.

 

Perhaps you need to talk to the guy with the 340 that is looking to put Rover heads on his engine. The Rover heads should be a direct fit to the 215. His thread is on the first page, same as yours.

 

You would need the lower compression pistons with the later Rover heads with the 29cc chambers. I would use the 300 heads with the earlier 3.9 Rover steel shim head gaskets on the 215 block. Use copper coat spray on gaskets. You will have to cut the valve guides down for over .450 lift. SBC Z28 valve springs. If you want pushrod oiling use later Buick 350 lifters and hollow pushrods. run a wire and spray wd40 through rocker holes and plug shaft oiling holes under shaft supports. Crower 50230 cam or similar. The Buick 11 to 1 pistons will give around 9 to 1 if you take .030 off the block and about .020 off the heads. Use around a 500cfm carb like the new Edelbrock AVS or Summit. Quick fuel has a nice 450cfm carb. Edelbrock Performer intake.

 

Thanks Jim, I was pretty sure you were a member here. I have read a bunch of your posts on the British V8 forum and elsewhere, all of which have been helpful.

Using your above info with the Olds flat-top pistons (again using the .0250 deck clearance number I saw somewhere), plugged into the CR calculator, I get 8.21:1, which seems to be a good preliminary number, prior to any shaving of the heads and decking of the block.

By "early" 3.9L Rover MLS/steel shim head gaskets I should be looking at 1989 or so, like these, yes?: https://www.summitracing.com/parts/mah-54694


MAHLE 54694



MAHLE 54694 Specifications
Additional Package Contents None
Cylinder Bore Diameter (IN) 3.61
Cylinder Bore Diameter (MM) 91.61
Cylinder Head Gasket Material Multi-Layered Steel
Gasket Sealant Included No
Item Grade OEM Standard
Material Multi-Layered Steel
Package Quantity 1
Thickness (IN) 0.02
Thickness (MM) 0.41

 

This topic?: https://www.v8buick.com/index.php?threads/rover-4-0-heads.384940/ Lots of good info in there.

I want to stick with either the '64 Buick 300 heads or the '63 Olds heads. While it may seem trivial, I like the old school look of the Buick and Olds engine parts. Plus, I have both on hand, and the head chamber size seems much better suited to the CR range I want to use. The '64 heads also allow for the use of the more modern alternator bracket, and P/S if I eventually use that, too.

 

The specs for that one are for the smaller bore. You want the one for larger 94mm bore so the fire ring is not inside the combustion chamber. These are the right ones:

Head Gasket Set - V8 3.9/4.2 Litre 3 row - Tin - RB7447 (rimmerbros.com)

Head gasket only, order 2:

Head Gasket Only - V8 3.9/4.2 Litre 2 & 3 row - Tn - RB7448 (rimmerbros.com)

 

Years ago I used the 300 steel shim gasket but the closer fire ring of the 3.9 gasket will add compression . I think the Fel Pro composite is the only one available for the 300 now.

 

You aren't going to like what I have to say I expect but I'll say it anyway.
The 300 is a better choice, especially given the parts you have on hand. To begin with it fits your goals for torque and output power in the stock 2bbl format, and it only weighs 80 lbs more than the 215 if you use the aluminum heads and intake that you already have. You may feel like 80 lbs is a big deal but it's less than your girlfriend weighs. It will not affect performance since the additional displacement will offset that weight easily and if you are concerned about handling then you should be aware of how to tune the suspension to deal with it. It will not change your weight balance in any significant way. Nothing fancy, do a stock build and you are set. No mix-n-match, nothing to figure out. Easy uncomplicated engine build and the famous SBB durability that comes with the iron block.

If you haven't read it yet, read this thread:https://www.mgexp.com/forum/mg-engine-swaps-forum.40/comprehensive-300-buick-build-thread.4463289/

I'm currently running an iron head 2bbl 300 in my MG and it is an excellent combination. Very tractable and easy to drive. It's about the same weight and gearing as your car.

Jim

 

Thanks, both Jims. I measured the '64 Buick 300 head's maximum chamber diameter in four places, and 95mm is the widest point, so with some material removed the 94mm bore gasket sounds just right.

@Jim Blackwood , I understand your viewpoint. It makes sense to stick with a stock-ish build of the '66 300 2-bbl engine I have now, especially since I have one almost entirely back together (although worn and tired) and ready to drop in, but...it's not what I truly want. I realize that means additional cost, difficulties, and challenges ahead, but I'm fine with that. I enjoy the challenge of figuring out what works and why, and with all of the excellent help and advice I've been reading and collecting over the last few months, I feel this is the right path forward. I do have the benefit of not facing a firm deadline to get this project running, and I still have structural repair work to do (in addition to finding and sorting out a different front suspension), so I have time to collect what I need.

Here are the head chamber diameter I mentioned above:








And the '66 300 I cleaned up and reassembled:

 

Look at Speedway Motors Mustang II suspensions.

 

Sure, you do you and make no apologies for it. Just saying, I started out with the 215, built and ran quite a few of them before being persuaded to try the 300 and I REALLY wish I'd started out with the 300. For one thing it's entirely possible I could have the same engine in the car I started out with and avoided all that effort spent to get where I am now. I'm just trying to help you out a little here. That doesn't necessarily mean you should do what I suggest.

Jim

 

I measured the intake ports on both the '63 Olds 215 and '64 Buick 300 heads last night:

'63 Olds 215 cylinder head intake ports: 15/16" W x 1-9/16" H
'64 Buick 300 cylinder head intake ports: 1" W x 1-23/32" H

So, they are very close. 1/16" wider and 5/32" taller on the '64 Buick versus the '63 Olds. Some material will be removed from the bottom of the head, so that will shift the ports down slightly, but I don't foresee any issues with enough head material remaining to provide a good sealing surface for the intake-to-head gasket. There's currently 5/16" of material from the base of the head to the bottom of the intake port on the Buick head, but I've only seen the steel turkey-pan style gasket for the 215, so not sure if there are other options on the Rover side of things?

I also measured the exhaust ports on both heads:

'63 Olds 215 cylinder head exhaust ports: 3/4" W x 1-3/16" H
'64 Buick 300 cylinder head exhaust ports: 7/8 " W x 1-1/2"" H (port is P-shaped, 3/4" W at top, 7/8" W at bottom)

Headers would be nice, and will be something I'll look into down the road, but for now, I'll be using the stock cast iron manifolds.

I would love to know the port measurements of the Edelbrock 2198 intake manifold if anyone happens to have one laying around. I don't see the port specs listed on their website, but really didn't expect them to be, either.



I mounted the '64 Buick head to the Olds 215 block again and took another (better?) pic for reference. Still unsure how that overlap area at the sides of the chamber is going to affect things, but I realized the '64 Buick exhaust valve head is actually .05" smaller in diameter than the 215 Olds exhaust valve while doing this. I've been reading and watching many videos (yes, some with a grain of salt) regarding chamber design, flow characteristics, valve sizes, etc....there are so many factors involved that it's difficult to get a firm, specific idea of how the head is going to work before it gets bolted on. I suppose that's why trial and error, as well as others' experiences, is so valuable in finding out the best combination for our specific applications. I am very much enjoying learning about all of the things which factor into cylinder heads, so it's time well spent for me.

Thanks for all of the comments, suggestions and advice so far.

 

Thanks. I was reading some online articles about valve guide refinishing/replacement, and found this one to be helpful. I will find out what the machine shop has to say when I bring the heads in.

https://www.enginebuildermag.com/2003/12/valve-guide-reconditioning/

 

Are you planning on using the Egge Olds high compression pistons. They are flat top with valve notches. The Olds heads have quench pads and may be better with those pistons. If you mill .020 off the 300 heads there will be little to no overlap.

 

I haven't decided on specific pistons yet. I now think I'd be fine with a CR above 9.0:1, but not sure I could achieve something in the 10.0:1 range using either the 54 cc '64 Buick or '63 Olds 2-bbl heads with the stock type Olds 215 flat-top pistons. I think the factory (slightly overrated) CR for the 4-bbl version was 10.25:1, but in reality 10:1 or maybe a tad less? I'm assuming I'll need to have the block overbored, so probably looking at new/different pistons anyway. I should have measured the piston to deck clearance while the engine was still assembled, just to have that firm number, but I didn't. Looks like around $600 for a set of Egge pistons for the 215, regardless of bore size, so I'm sort of keeping that number in the back of my mind as a rough piston cost.

I think I would need to have .020(?) removed from the block deck surface, too, in order to get the CR up enough to make using the (milled) '64 300 heads worthwhile? 54cc going down to the 38/37CC (Olds 4-bbl/Buick 215) range is quite the jump, but it seems I'm starting out with the two worst possible cylinder head options for a high compression build here. I'm all for using the '64 Buick heads and not buying something else if I can get to 10:1 or so without anything too exotic. An extra 30 hp with a smaller combustion chamber is a worthwhile change, even if it means premium fuel. This isn't going to be a daily driver, and I live in a major metro area where access to premium is never an issue, so despite me saying earlier non-premium and 9.0:1 CR is ideal, the more I've learned about detonation, chamber shape and configuration, etc. I think I'd be comfortable and happier with the additional potential power output of a higher CR from the start.

So, yeah, still a lot to think about and decide on.

 

I'll admit I'm having a little trouble reconciling statements like saying an extra 30 hp would not go amiss with this thread in general. Let me try to explain that if you would. The 215 was innovative, and it was also limited. At the time 1 hp per cu/in was fairly serious performance territory and very few engines were at that level, really probably none in standard production except special models or exotics. What this meant is that engines at that level and above were not considered suitable for the average driver and would cause headaches for the manufacturer. It's kind of important to keep that in mind. If I've interpreted it correctly the stated intention here was not to wander into that territory.

The 215 and 3.5L Rover variants output a range of power from a maximum high of 210 hp down to a low of 137 hp as used in the MGB. Most common was probably around 180 so an extra 30 hp represents the difference between the average 215 and the turbocharged version, or perhaps the 11:1 variant found in a small number of Buicks. In going there you are certainly bumping up against the territory that was to be avoided, yet oddly enough the engine that can easily handle this is not to be considered. Because of weight? OK have a think about that for just a second. In a 2400 lb car with 200 hp you are at a 12:1 power to weight ratio, very nice for most cars and not quite into the hot rod range yet. Another 30 hp bumps you up to 2760 lbs at the same ratio. Is it beginning to make any sense why I think the additional weight of the 300 is not an issue? To offset the extra weight of the 300 (with aluminum heads and intake) requires less than 7 additional horsepower.

That is well within the performance envelope of the engine at standard factory specs. Easily achieved by any variant, in fact the base engine, the iron head 2bbl version produced 210hp/310tq at 9:1 compression. So right off the bat the hp target is reached or exceeded with the most basic build imaginable, but look at that torque number. Torque is the thing that makes a car easy to drive. In general the higher the torque is the easier it gets. Fewer concerns about clutch release, less issues with idle, and instant smooth acceleration. Such an understressed engine gives a longer service life as well, no small concern when compared to an engine that had a well deserved reputation for reliability issues. (Note, the late Rover versions are about 30 lbs heavier due to extra metal in the block and heads and still had issues.)

As much fun as it is messing around with different heads and pistons and compression ratios to build something that is beyond it's original design targets (and remembering that GM was competing in the horsepower wars at the time) and thereby increasing maintenance and reliability issues while bumping up against the practical limits of the design there is a great deal to be said for taking a more sensible approach that will yield more comfortable and inexpensive results while providing a path to easy power gains in the future if desired.

Remember the 7 hp figure needed to offset the additional weight? How about 50 instead? Well within reach and now you ARE into hot rod territory with a p/w ratio of 10. It's not always all about reducing weight.

Jim

 

I agree, and it’s not always about running a deeper gear.
I say make the engine as powerful as you can afford, and that right there puts the 300 in the winners circle compared to the 215.