Hey guys. This thread really started here on post #34: https://www.v8buick.com/index.php?threads/65-special-300-rebuild.316354/page-2 So to first respond a bit to options on this swap, the MGB can and has been fitted with any later Buick engine from about '61 on up including the 215, 300, 340, 455 and V6. You'll note the exception of the 350 and there are reasons for that which I'll get into shortly. It's my position that the 300 is by a significant margin the best choice, however the 215 is the most common by far. Again for good reasons. MGB V8 engine conversions began almost as soon as the car was introduced, with a couple of early documented swaps back around '62. These early swaps seemed to be pretty evenly split between the light weight 215 and the SBF and there weren't very many of them. By the late 60's however, Ken Costello who was a UK hot rodder had started building Rover V8 conversions in the UK and as we all know by now the Rover was a Buick 215 dressed in British accessories. MG got the message and began selling the car with the Rover engine as an option by the mid '70s. Meanwhile, in 1964 Buick began selling the 300 with aluminum heads and intake, which is relevant because that engine, with an iron block and decks just 9/16" higher than the 215 and an intake that put the carb at almost the same height, weighed only 50 lbs more than the MGB 4 cylinder engine. A tidy little bit of info that we only discovered many years later. As the 300 is 80 lbs heavier than the Buick 215 you'll see that this diminuitive Buick powerplant was actually about 30 lbs lighter than the stock 1800cc engine originally fitted. Well, actually 32 lbs but close enough. Also of interest, the later Rover V8, after bulking up by a bit of displacement and an additional 30 lbs was at nearly the exact weight of the 1800. All of which is important because the MGB's forte is handling, which is considerably affected by weight distribution. Fortunately it is also a front-mid engine design making it less susceptible to engine weight changes as that weight is behind the front wheels. So because of Ken Costello and factory involvement, the MGB/V8 BOPR swap (Buick Olds Pontiac Rover) became instantly legitimate, with the result that many looked no further than the 215/3.5L BOPR and this situation persisted for quite a few years during which time the Rover increased to a limit of a full 5 liter displacement or 300 cubic inches. Along the way, one or two pioneers, in particular Mike Moor, decided to try the Buick 300 on for size and found it had much to recommend it. It was and remains much more reliable than the BOPR due to the iron block. Weight was really not an issue (only 50 lbs heavier than the late Rover or the OEM engine) so it did not affect handling, it was cheaper, and more powerful. It could use all of the BOPR swap components including mounts and headers but importantly, bellhousings and flywheels could be had for sometimes as little as 1/10 the cost of BOPR parts. And, as we now know it could be rather easily stroked and bored to a 350 cubic inch displacement. Because the cars after 1974-1/2 were built to accommodate the Rover V8 it can be a bolt-in swap, requiring only that you are careful about air cleaner height. However, the BOPR remains the #1 swap, followed by the GM V6-60 which has gained steadily now for several years but the production of which ended in 2005 and which never had significant aftermarket support, then the SBF as a distant 3rd. The Rover continued in production until 2007 and was widely considered the SBC of Europe, a claim not to be taken too lightly. Meanwhile the 300 gained a few adherents including Chris Gill's beautiful stroked 300/350 in Canada and Jim Stuart's Yellow rubber bumper (RB) late model MGB sporting an RV-8 hood. Oh yes, the RV-8 was MG's second foray into V8 territiory, built on the MGB tub but with upscale accouterments and yet again, not exported to the American market even though they did export it to Japan. Why is the 300 the best choice though? Why not the 350 or the 455 for instance, and why not the V6? Various reasons. Aside from any engine with fewer than 8 cylinders being a communist plot to begin with, (or more than 8 for that matter) it lacks headers. That's really the only reason. That and the sound. The 455, though light enough to make it work requires some ballasting to keep the weight balance within reason. We used a Jag IRS to do the trick. But it also requires TA heads to fit the exhausts in, dropping the steering to lower the engine, modifying the lower control arms to clear the steering, changes to the firewall, and a hole in the hood, among other things. Not a casual weekend swap by any means. The 340 also requires all that except the TA heads and ballast, and the 350 needs everything the 340 does AND the new TA heads for weight reduction plus custom headers. Might as well go straight to the 455. (The 340 can use the '64 300 heads. In truth, the car could handle the weight of an iron 340 or 350 but handling would most likely suffer somewhat.) However, the BOPR and the 300 are capable of being done in a weekend under the right conditions and given the right year of car. Why would you pick the 300 over the BOPR? Let's consider the major difference, that iron block. First, there will be no threads pulling out before reaching torque and in fact torque will be sure and firm rather than iffy and mushy. There will be no cracks at the mains or behind the liners, or liners working loose to rattle up and down. The cost for a 5 liter motor is almost exponentially lower as larger displacement Rovers claim a premium and the inexpensive limit is 5.7L instead of 5. Finally, the iron block is more rigid and gives longer life and better reliability. You can even powder coat it to look like aluminum and hardly anyone would suspect. In my own personal car I have the 340, but had I known I would certainly have done the 300 instead, most likely with the 350 crank. However it is a pretty special engine and there's a thread here that follows the build so I won't go over all that again, and I don't intend to replace it. But that's not to say I wouldn't consider building a 300 for another car if I happened to run across a particularly sweet deal. That and I like to keep abreast of any news regarding the 300 in order to pass it along to the BritishV8 enthusiasts. So with that in mind, what was it you were saying Derek, about 300 build options? I'm all ears. Jim
Nicely summed up Jim. The work on th MGB455 is awesome, but I like the reasoning here in favor of the 300. back in the 70's sometime Dad purchased an Oldsmobile with the 215 just so he could check out the engine. I've still got the 215 in my shop for "the Future" ie a swap into a light foreign car... i wanted to put it in a Manta but was told it would be too much work...by Dad, (the guy who swapped a Desoto Hemi into his 53 Corvette.) Plenty of projects keeping me busy already though. Are you tninking of building another MGB V8? Ted
I could consider it Ted. I've got a '74-1/2 sitting in the shed which we were going to use for a Chump car but that build has stalled for the time being. Presently it has a much used 3.1L V6-60 sitting in it but it's a nice straight and rust free body. I'm not so crazy about the commie engine in it but it gives the gang an excuse to show up here for a few weekends a year. It could evolve though if I found the right engine. Of course the current craze is LS this and LS that. A few of those have been put in MGs as well but so far nobody has been able to do it without hacking up the firewall. In keeping with tradition and some semblance of originality the 300 is the right choice, but there's no denying the newer engines have some appeal. Still, how much horsepower do you need in a maybe 2400 lb car? (Some weight increases are inevitable.) So it's hard to say. I do like a challenge, and the 340/AA80E/JagIRS MGB with hydraulic forward tilt bonnet and air ride has been the biggest challenge yet. It will be a tremendous relief to be able to drive it at last but there is still a lot of work to do before it is finished. A/C to be added, straightening of the body is needed followed by new paint (again) and then a completely new dashboard. Once it is finished I don't think it will ever be replaceable. So building "just another" SBB/MGB doesn't excite me the way it once did. OTOH it would be sorta nice to know all the tricks going in. Having explored all the edges of a Buick/MGB swap I can say with complete assurance and no hesitation whatsoever that the 300 is the best of the bunch. The 300 with forged pistons, 350 crank, roller cam and TA heads would be entirely exceptional. Then again, experimenting with the LS does have some appeal. Can it be done without cutting, that is the question. Scott Costanza used an LS4, considered the most compact version. But despite all I could do to persuade him to go that direction he decided he wanted the engine low and set back so he cut the firewall. Now he has expressed the opinion that it would fit, but nobody has yet taken the bait. So it's somewhat tempting. If I happened across a direct injection LS I might consider it, particularly if one of those new multi-gear automatics came with it. Not Buick, I know. But it'd be hard to pass on that, just to know. Would it be better than the built 300 above? I think that is really a valid question. What does the LS really have (not the DI version) that the 300 cannot have? Once you have the TA heads and the roller cam what is really left? Roller rockers? do-able. Good ports? ditto. Some sort of Black Magic in the chamber shape? Yet to be proven what exactly that might be worth from what I've seen. So what is it? Electronic controls? No problemo. What then? I wonder if DI could be added to a TA head? Jim
You could add DI to any head if you were motivated enough. Then you are back to carving weird shapes into piston tops and chambers to make up for lost mixture motion.
Probably so, you have to wonder how you could get anything close to a homogeneous mixture with DI. But apparently it can be done. How good is it? Probably not nearly as good as is claimed, but time will tell. I have no doubt it will get better. Better enough to supplant all prior designs though? Well maybe but the jury is still out. One thing Buick did that I've spent some time trying to decrypt, is the use of tall compression heights. Comparing Buick pistons to more current designs we see a great deal of room between the piston pin and crown, and large diameter, heavy wrist pins. What I've learned is that the longer compression height reduces wear on the piston and the large wrist pin stabilizes the ring package by stiffening the piston itself. It was quite interesting to learn that piston makers are evolving back to steel pistons for the stiffness and durability needed to endure the pressures and heat of 135 upwards towards the anticipated 175 hp/L of modern engines. A 5 liter engine with 875 hp? Stock? Well alright then! But I digress. It is quite evident by now that Buick was concerned about cylinder life. Otherwise why spring for so much nickel in the block? Why use so much compression height? And their details paid off, as Buick engines hold up well over lots of miles. At the time they were combating the effects of lead in the gasoline which we do not have to deal with today and the benefit for us is durability not really so far behind today's quarter million mile engines. That's not something you could even hope for from most 60's era engine designs. You hear plenty about micro-honing but the real advance came from cleaner gasoline, just the same as engine life improved dramatically with the advent of the intake air filter. Anyone who lived through filthy oil at 2000 mile change intervals will see the truth in that. But back to the compression height. Modern pistons are stronger, stiffer, and more friction resistant so the need for compression height is reduced. How far? JE Pistons has gone on record as claiming that a 1" compression height is enough for a NA engine. Obviously wrist pin diameter influences this as a relatively small 3/4" wrist pin leaves less than 5/8" for the ring package if it sits below the oil ring. But the CH of the Buick 300 is a whopping 1.81" IIRC (1.825 according to TA) so even using a more conservative 1-1/4" CH leaves an easy 5/8 of an inch of usable distance in the reciprocating assembly. Why is this important? Simply because the deck of the 340/350 is exactly 0.644" taller than the 300, meaning that with the right pistons a 300 can be built with the reciprocating assembly from a late 350, and retain all the advantages of the stock rod ratio while remaining reasonably conservative in piston design. So in short, Buick's concern for engine life means we can now build a 300 based 350 which is possibly the smallest, lightest, most durable (and powerful?) 350 available. No mean feat for this particular application. I think you can see why I like this engine. But the key to it all is in choosing the right pistons. Jim
If the Buick 300 is a tall deck variation of the 215, how much can it be decked to extreme? Can I make it into a iron 215, or close?
How thick is the deck and why would you want to? Technically... you could braze a new deck to the cylinder sleeves, it's done in a similar manner for diesel/industrial gas engines.
I want to build a short stroke version. The stock 300 has a very tall deck, long stroke, long rods, & huge compression height (as Jim mentioned). It all adds up to too much to overcome for a short stroke engine. With modern pistons, 6" rods & a 3.03 or 3.22 stroke the piston will be waaay down in the hole. Unless, I can shave half an inch off the block. :eek2:
I'm aware of all that (except the fact that you WANT to). The machining aspect is fairly simple with access to the right stuff, just curious if you are looking for some kind of performance edge or chassis fitment?
If the short stroke is a must, I'd keep the rod as short as practical and the piston long (modern design though). Don't want to slow down piston speed too much or you NEED ridiculous rpm to make things work. All else equal, the benefits of a short deck are better than simply lighter weight in a longer package.
I encourage people using the basic castings as "raw material" to do whatever they want to, no holds barred. There's no satisfaction in bolting together cookie cutters, for me anyways.
Not sure if you remember me Derek, I've been on this board a long time, just not so much lately. There's a multi-page thread about my 340 on here somewhere if you want to look for it. Anyway, thanks for the post. I'm sure it will be useful to someone. But where you and I don't mind going to extremes to build the engine we want, I suspect most would prefer to keep it as simple as possible. That's the beauty of using the 350 internals. In the first place, the crank and rods are cheap and very common, and all they'd have to do is have the main journals cut down. No crank grinder is going to complain too much about that so that part is really simple. And really, that just leaves the pistons and that is just about as simple a plan as it gets. So I was wondering if you would mind if we could discuss piston choices for that build? As you know there are a lot of details about the pistons that should be discussed but by using the 350 rods we limit ourselves in terms of possible wrist pin sizes which cuts down the choices some. Also since quench is sometimes referred to as "Free octane" that is something we should insist on. Then of course compression height, static and dynamic CR, skirt design, coatings, cast or forged, and of course, price. Then it would be good to look at all the other options in terms of stroke and how to get there. Probably what most want would be satisfied with the Olds 307 pistons Sean suggested. I know Carl has been Jonesing for a good short stroke motor and we looked at the 300 but he didn't think he could get there with that. But what if we put the 350 rods in a 300 block with 300 pistons and a 215 crank? Would that do it? I haven't looked that combo up yet, just wondering about it. Any ideas? Jim
Derek, I hate to call you out on this but you were very rude to Carl. He is serious about what he wants and just because you don't understand is no reason to ridicule him. Really, an apology is called for. Jim
That wasn't overlooked when I said it's just a matter of motivation. Solutions are not that big of a deal when you look at other engine types and how they assemble. Plenty of them run long bolts down into the lower part of the water jacket or have wet decks. You could do anything you wanted to if so inclined. Many of these non popular platforms aren't practical from many standpoints. It's not uncommon to bronze braze broken main caps on Caterpillar blocks that are 8 feet long (or bigger) that move huge amounts of weight and trust that it holds when there are $100's of thousands of dollars on the line in down time, repairs, replacement castings, etc. The reason you don't see this with automotive blocks so much is that they are cheap throwaway castings. We did this for rare iron Hemi, BBC, or whatever, but really didn't want to bother with 'that' clientele either. [BTW, industrial casting repairs guarantee the entire cost of the repair, including related failures beyond the work piece involved. You get what you are willing to pay for...assuming you don't have the skill to do this in-house]
Definitely not trying to push the idea, just pointing out proven things that have been around for 50+ years. One OEM CNC shop I was at made new decks from blanchard ground steel that we silver soldered rough honed iron cylinders to, then finished on the sunnen hone after straightening. They were meant to be replaced at rebuild with new stock pistons. Maybe one failure out of tens of thousands and difficult to pinpoint cause...not likely a manufacturing defect.
I guess I thought that these forums were for information sharing? MGBV8 has a dream. Although it may seem difficult for some to fathom, I can assure you that this level of work is being done every day, and to a much larger scale than you suspect. The work itself is quite simple. This is no different than anyone explaining how to offset grind a crank to someone unfamiliar...their world goes from flat to round. Starting with a block is going to be much easier than a solid piece of stock. Like anything else in the world of hot rodding or machining, you either take things on because you have the skill or pay the premium price. I might assume that some members might be quite skilled in trade but are maybe unfamiliar with aspects of performance or racing. I'm not here to generate business or 'hook anyone up'. If you have something going on here, I won't ruin your flow. I know this reads like arguing, but the comments are crossing. Sorry if it seems like I'm partaking in hostile discussion, just leaving information. :TU:
Seems to me that this thread really went sour in a hurry, and Derek, to me it appears that you are solely to blame for that. I haven't seen you act up like that since you first showed up here, but are you making a habit of this? I hope not because if so, I'm outa here for good. You apparently started out by calling my supercharger a "boat anchor" but I let that pass. Looks like that was a mistake. Then you badmouth anything that doesn't go straight down your own narrow little street. Let me tell you something kid, very few people indeed have any desire whatsoever to follow the path you have blazed so your best bet is to just pull in your horns and learn some manners. I can hardly believe you have gone so far to embarrass me in front of my peers after I went to the trouble to post links to this thread on two different forums, and were it not for the information in these posts I would have already taken steps to remove the entire thread. I foresee that as being the very next step unless you post a sincere apology and then conduct yourself in a manner befitting a civilized human being. Even then this thread may be too damaged to be worth saving. Jim
There you go Jim, all cleaned up. I was just joking around with the boat anchor remark by the way, that's why I said to put it on the stroker to make even more power. o No: The joke being that the blower is a crutch to get to the power level you could get to without one with a sbb 300 stroker. I will delete this post after you read this too as to not clutter up your thread. Now you can discuss away cutting decks off of blocks and brazing them back on all you want. I understand that the things discussed can be done as well, if someone wanted to spend thousands of dollars to have it done, could buy an LS crate motor for what it would cost to have something like that done to just the block but its your thread so, carry on. I'll even go as far to say that if Carl really wants that done to a sbb 300 block I can do that for him for $8,000, that would only be $1,000 per hole plus materials. That would include installing the custom shouldered sleeves that he purchases, newly machined deck brazed on and all the hardware, pressure testing and machine work to have the block ready to be machined for his pistons. Sonic testing probably wouldn't be necessary when cutting off the decks to the water jackets to see how far it can be bored to know how to order the custom sleeves and know what size piston he can get to. But more than likely would be lucky to get back to a 3.75" bore size. So not only do I understand something like this, I can actually make something like this happen, instead of mentioning it and back peddling about the subject. IIRC the newer Rover block cranks have the 2.500" mains, so perhaps Carl can source one of those cranks to have a shorter stroke. If not I'm sure I could make spacers to fit that crank in the altered sbb 300 block if he needs those as well. Of coarse spending that kind of cash on the block he'll probably want a billet crank anyway. I can also make billet main caps for the block as well if he wants that as well? My apologies Jim, don't leave because of me. Like I mentioned above, I will delete this post for you as well. Derek
My avatar is my Buick 215 JN block that has been in my '79 MGB for almost 16 years. Sweet li'l engine that fits my engine bay well. IMO, a free-revving short stroke engine is a great match for a sports car, especially for my style of driving it. I don't need nor want a long stroke, big torque muscle car engine. Just a few more cubes. Maybe 265-280ci. The 215 has a stroke of 2.8", the Rover 4.2 stroke is 3.03" & the Rover 4.6 is 3.22". Buick 300 is even more at around 3.4" I have two Rover 3.9 engines & a 4.2 crank. Problem is I do not trust the Rover aluminum block. Way too many slipped liners, blocks cracked behind the liners. & stripped threads. Boring one to use Chevy 305 pistons is risky. With the Buick 300, I can reuse my engine mounts & headers & gain that iron block that Jim is so fond of. I have juggled the numbers with the 4.2 crank & the 4.6 crank along with longer rods & different pistons. I could make it work if that block wasn't so tall. I didn't realistically expect to be able to lop a half an inch off the block. Just kickin' around ideas.
Like you probably figured out that what was discussed can be done, but not really practical, but I will do it if you want that done. Sorry for saying what you were asking about might of been ridiculous, I wasn't sure if you were serious or not. o No: Not a really common thing to do to a cast iron block for a car, maybe more common and perhaps cost effective for industrial applications, not so much for this type of engine though. Hopefully there are no hard feelings, none of it was meant that way. Anyway, with the current deck height of 9.543" and a piston with a 1.933" compression distance you can run the 3.22" crank. The AutoTec pistons that were posted could be made to that spec for a whole lot less than cutting the deck down. Oh yeah, these pistons with a 1.855" compression distance weighed 2.8 lbs for the set of 8 less than the "stock" replacement hypereutectic pistons that they replaced, so with an extra .078" more compression height I would still think that they would still be lighter than the pistons that the factory originally put in the sbb 300 when it was new. Also, just because you build a sbb say 350 out of a sbb 300 doesn't mean you have to cam it to have low end grunt, which you could. But you could also cam it(solid roller would do it) to start making power above 3,000 RPM all the way to 7,500 + if you wanted. A milder gear ratio can be used as well to keep the power in check in the light car, probably a 2.56:1 rear gear could be used and still be able to take off like a bat out of he!!. That would require Aftermarket rods(sbc rods are inexpensive and easily altered to work in a sbb) well ported TA Rover heads or equivalent and a custom intake unless you can adapt one of the Rover offerings to make it spin to there, but still less than having the mentioned block work done. GL Derek
