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Rzrryan
Ryan Lambert

(2 posts)

Registered:
05/07/2022 12:21PM

Main British Car:


Olds 215 boost
Posted by: Rzrryan
Date: May 07, 2022 01:44PM

In the coming week I'm going to look at a 62 olds cutlass with a 4 barrel 215 in it. I've been doing research on various things like disk brakes and manual swaps and the like I've been able to find limited but good info on all of that and have put together what i feel is a reasonable plan on that front. The one thing I haven't been able to find is information on is how much can these blocks and bottom ends handle as far as boost and hp and if the added flow of something like a rover or buick 300 head would be worth the decreased head gasket clamping force in a boosted application. My goal for the car would be about 300-325hp to the rear wheels but I do not want to greatly compromise reliability to do so if at all possible. Specifically what I'm trying to gather is a rough idea of what it would take to get there or what would be a more reasonable goal if im out of line with my thinking.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6218 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Olds 215 boost
Posted by: BlownMGB-V8
Date: May 07, 2022 10:58PM

Ryan.... I've been there. This is going in an MGB? Or are you restoring the Olds? If restoring the Olds most of what I can suggest is not going to make you happy, but if it's an MGB I can save you a whole lot of time, effort and money and get you to your end goal a whole lot quicker.

First off, as you reach and exceed the 300hp level the BOP 215 will be struggling to stay together. As long as it is at 200 or less it'll usually be just fine but at higher power levels the strength of the block becomes an issue, particularly in the area of the threads in the main and head bolt bosses. You don't get a 60lb block without some compromises and it really isn't that rigid. For what it takes to build the equivalent of an old F1 level powerplant to handle the power, well there is a much better way, and that is it's successor, the Buick 300.

Don't be overly concerned about the extra 80lbs. Remind yourself that this still only puts you 50lbs heavier than the stock 1800cc engine and that is not a problem for handling. A front end spring change might be desired, but those are available and not particularly expensive. Chances are you might be thinking about that anyway as part of a handling upgrade. You really have to ask, if Buick needed to more than double the weight of the 215 block's design to make it a proper V8, how could the original possibly be adequate? Well the fact is, that had to have something to do with it's short production run life. It's been well documented that they had some problems. Mostly having to do with casting porosity and most of those problem engines are long gone by now but all the same, the engine was something of a compromise and not really well suited to high power levels.

But that extra mass in the 300 block is not just weight. To begin with it is a high nickel content alloy that is rigid, long wearing, and allowed Buick to pioneer thinwall casting methods that make the SBB one of the lightest V8 packages available with exceptional power output, with potential maximums in the 700-1000hp range. You won't get that, but Mike's N/A 300 MGB dynoed 300rwhp and is a perfectly streetable car, so your goal is well within reach.

When combined with the MGB it makes arguably the best possible combination of car and engine. Even the lowly 9:1 CR 2bbl iron head 300 makes for a very nice package and I can say that because I've been driving just that for the last year. It's only taken me about 4 decades to get to this point, starting from right where you are now. Best yet, it's a package that is easily upgraded using any of the traditional hot rodding methods.

I've had a 215 Olds, a highly strung 215 Buick, an Olds Jetfire, a supercharged 215, a supercharged 340, and now the iron head 300, with an injected and blown roller cam 300 (346) stroker now on the build stand so I know whereof I speak. Starting from where you are now, ANY 300 is a great starting point. If you have the cash to build a blown or turbo 215, you can do things with the 300 like a roller cam for modern oil compatibility, upgraded rods and pistons, aftermarket heads or whatever you like and it's a great platform to start with, unlike the 215 where you are at it's limits starting out. If it turns out that the performance you get from the base engine is everything you want (a very likely possibility) think of what it's saving you while you are enjoying the car.

Jim


Rzrryan
Ryan Lambert

(2 posts)

Registered:
05/07/2022 12:21PM

Main British Car:


Re: Olds 215 boost
Posted by: Rzrryan
Date: May 08, 2022 02:59PM

I wouldn't necessarily call what id be doing restoring but I'd be staying with the olds platform but as the deal isn't finalized until cash changes hands and the cars on the trailer nothing is set in stone just yet. With that being said along with the admission that im aware any chassis specific questions are likely not going to be answered as well on a British sportscar forum what dimensionally are the differences between a 215 and a 300? And what about in the case of a 340 or 350 buick?


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6218 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Olds 215 boost
Posted by: BlownMGB-V8
Date: May 08, 2022 04:59PM

For the '62 Cutlass you have a wide range of engine choices. First, aside from the iron block the major difference between the 215 Buick and the 300 and the 340 Buicks are deck heights and of course by extension engine height and intake width. The Buicks use a noticeably different valve cover and they are not interchangeable. However the 300 and 340 valve covers are not THAT different. Still, anyone who knows will spot it. So if you want a "stealth" build what you might do is put Olds 215 heads on a 300 block and silver paint or ceramic coat the block to disguise it. That and a decent cam and good headers will get you reasonably close to that 300hp mark though it will suffer a bit on the top end.

Now if you don't care about disguising the engine there are two branches you can pursue: Buick or Olds.

If you choose to go Olds for brand loyalty, and I can't say that's a bad idea, the Olds 350 is a very fine engine. It has a 4.057" bore size (3.385" stroke) and in stock 4bbl trim for 1970 put out 310hp with a single exhaust. Most feel that engine was under rated. It is a bit heavy but in the '62 Cutlass would make for quite the little monster. Very likely the engine mounts would be a bolt-in proposition and other parts salvageable from later F85s. I have a soft spot for that engine, with performance points in the distributor it would hit 6 grand and do it all day long.

Because the major difference between the 350 and 455 Olds is again, deck height, it would also be feasible to install the 455 and the weight shouldn't be much different. (about 45 lbs) The bore is 4.125" and stroke is 4.250 so it is undersquare. The BBO heads fit the 350 and have bigger valves so what you have with the 350 is basically a destroked 455, and where the 455 cars were about what you would expect, the 350 cars were surprisingly quick.

The weight advantage of ditching brand loyalty and going to the Buick engine can be as great as nearly 200lbs but is likely to be less. As a practical matter it is likely to be in the 100-150lb range and 80-130 lbs more than the 215 although both big blocks weigh about the same. Your choices here are the 300, 340 or 350 as well as the 455 with either iron or aluminum heads but the 300/340 has more choices. The 455 is also a short stroke oversquare engine at 4.3125 x 3.9" bore and stroke. We have put one in an MGB and have been very happy with the results. (see Roadmaster threads)

The aftermarket alloy heads available are expensive, heavy and very very good. There is a wider range of choices for the 455 than for anything else. But, due to the Rover variants there is a very good selection available that will fit the 300 and 340, and the late Rover heads use the same chamber volume as the TA/Rover performance heads so a straight swap is possible. The 350 has one alloy head choice and it is a good one, but currently on back-order and others are not interchangeable.

So where does that leave you? Sort of depends on what you can find. The 300 came with both alloy and iron heads. With alloy it weighed 400lbs or about 80 lbs more than the 215. Those engines were just made for one year, are hard to find and expensive when you do find them. The iron head 300 weighs 50 lbs more and has bigger valves and ports, is more common and much less expensive. The 340 was used for only a year or two before the 350 came out but it is a good engine. Weighs only a couple pounds more than the 300 but has a taller deck so it is a larger engine. The 350 is by far the most common and easiest to find. It is well supported by TAPerformance with the aforementioned heads and at least 2 aluminum intakes and any other parts you might want.

You could also consider the Buick V6 and the late Buick 3800, also available in a supercharged version from the factory.

But you have some decisions to make about which direction you want this to go. Any of the above would be feasible with minimal changes to the car itself and things like headers, mounts and radiators should be easy enough to find.

Jim



Edited 1 time(s). Last edit at 05/08/2022 05:02PM by BlownMGB-V8.


joe_padavano
Joseph Padavano
Northern Virginia
(152 posts)

Registered:
02/15/2010 03:49PM

Main British Car:
1962 F-85 Deluxe wagon 215 Olds

Re: Olds 215 boost
Posted by: joe_padavano
Date: May 09, 2022 03:10AM

Personally, I'm going with a cross-bolted 4.6 Rover block and Buick 300 crank for my 62 F85 build. I'll be using ported Olds heads for optical reasons (and yes, I'm aware of the valvetrain and oiling differences). I've got a T5 with a D&D bell for the trans.


MGBV8
Carl Floyd
Kingsport, TN
(4284 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB Buick 215

authors avatar
Re: Olds 215 boost
Posted by: MGBV8
Date: May 09, 2022 08:45AM

Most will never know, Joe. ;)


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6218 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Olds 215 boost
Posted by: BlownMGB-V8
Date: May 09, 2022 10:36AM

I honestly think If I was doing one of these I'd go with the 4bbl 350 Olds engine. It's a straight upgrade within the Marque and would turn it into a little rocket. If I could find them I'd fit a set of big block heads and look around to see if there was a mild roller cam I could use for modern oil compatibility. It's a very rugged engine and very well made.

Jim



MG four six eight
Bill Jacobson
Wa state
(318 posts)

Registered:
10/23/2007 02:15AM

Main British Car:
73 MGB Buick 215, Eaton/GM supercharger

Re: Olds 215 boost
Posted by: MG four six eight
Date: May 10, 2022 01:27AM

Ryan,

The 215 will handle boost as long as you don't get to crazy will the boost pressure and RPM. I think Jim was probably pushing the envelope more than I am, by running higher compression and higher boost levels.

I run 11 PSI of boost with 8.5 to 1 compression ratio, ported heads and a custom ground camshaft. While it's good power for a light sports car, it's probably not the 300-350 hp at the rear wheels that your looking for. To get to those power levels reliably you'll need more cubic inches such as the examples Jim suggested above. Or even the cross bolted 4.6L Joe mentioned

For supercharging/turbo applications a 215, I do recommend using ARP main studs, head studs, rod bolts as well as having the block line bored along with the usual oiling system mods. IMO forged pistons are highly recommended. I tried using cast pistons originally, but had sealing issues with them while under boost.
Additionally running an oil cooler is a good idea. With boost, the pistons can get much hotter and they are cooled primarily by oil spray from the rod bearing weep holes. By keeping the oil temperatures in check it helps cool the pistons better, which in turn helps reduce detonation while under boost.

Bill



Edited 1 time(s). Last edit at 05/10/2022 01:31AM by MG four six eight.


Jim Stabe
Jim Stabe
San Diego, Ca
(818 posts)

Registered:
02/28/2009 10:01AM

Main British Car:
1966 MGB Roadster 350 LT1 Chevy

authors avatar
Re: Olds 215 boost
Posted by: Jim Stabe
Date: May 10, 2022 11:44AM

As another data point I ran a 215 Olds with just under 9:1 compression with a Jetfire turbo at 15 lbs boost then later with 12 lbs boost for 10 years with no problems. Engine then was sold and put into a dune buggy and continued to run (lost track after it was sold).


joe_padavano
Joseph Padavano
Northern Virginia
(152 posts)

Registered:
02/15/2010 03:49PM

Main British Car:
1962 F-85 Deluxe wagon 215 Olds

Re: Olds 215 boost
Posted by: joe_padavano
Date: May 12, 2022 04:13AM

An iron small block Olds weighs just about twice as much as a BOPR motor. Add the weight of the stronger trans and stronger rear axle, and you've bumped the 2700 lb Y-body 1962 car to a 3500 lb 1964 A-body, and paid a significant premium for that. Add the cost of larger brakes to stop this behemoth, and beefed up suspension to carry that mass, and you might as well just start with a 64-up A-body car.

On the other hand, a 4.6 Rover-based build can easily get over 275 HP without increasing the weight of the car. Now you've got less than 10 lb per HP, which is better than a 1970 Olds W30. Why spend the money and time to cut up the car for an iron block motor, and completely screw it up in the process. What matters is power-to-weight. Raw HP numbers just impress the uninformed, who aren't worth the bother.


roverman
Art Gertz
Winchester, CA.
(3170 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Olds 215 boost
Posted by: roverman
Date: May 17, 2022 07:23PM

Just how " original" must you have ? A cross-bolted 4.0/4.6L is a good platform to start with. I pc. rear main seal, stronger
crank/rods/ main caps/ etc. With skilled cutting/ welding, you can put Olds rocker covers on the Buick/ Rover heads. What trans ?
Don't bother with stock Olds hydro under ANY circumstances. T5 stick or AW4 auto will work. Don't expect stock rear to hold
300+ hp at rear. No gears or posi available. 8" Ford would work.
Good Luck, Art.


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