Well Jim, if you've got the hankerin' to try something different with a 340, this item crossed my radar screen last week. It's a single plane intake for the Australian P76 V8. It's deck height is taller than the 215 or 300 but slightly less than the 340. With some 1/4" spacers, it can be made to work on a 340. However, the ports are 215 sized. You'd have to mill them out to aluminum head 300 size. They won't go any larger than that. This version is set up to take fuel rails and injectors. Pretty neat! Greg
Bob, Thanks for the interest in my project. I do have most information on the cardomain page but if you think people on this list would be interested I could write up all the details and post them on the list. It will be a LONG post I think. I actually took the block out to it's limits at .040 over. I figured when I do it again I'm going to resleeve with bigger top hat sleeves. The final bore is 3.74" as close as I could get to the stock 3.75". Great news BTW! All of my parts are officially done. Balancing, Blueprinting, and Custom machine work. The shop said they had so much fun working on it they gave me a $300 discount! So my earlier number of $5272.57 can be revised to $4972.57. SWEET. The best part was how they listed my engine on the job order. Buick/Rover/Chevy/Ford/Pontiac/VW. LOL! Greg, I like where you're going with the suggestion of using the P76 but then he'd be stuck with the 3.5" bore. Lot's of valve shrouding... OR he could resleeve the block but that can be expensive... Good thinking though.
Here's a quote from Dan Jones, posted on the 215 list: "Engine Years Bore Stroke Main Rod Rod Deck Pin Diam Diam Length Height Height 215 61-63 3.50 2.80 2.3 2.0 5.66 8.96 300 64-67 3.75 3.36 2.5 2.0 5.95 9.50 1.831-1.842 340 66-67 3.75 3.85 3.0 2.0 6.38 10.15 1.831-1.842 350 68-79 3.80 3.85 3.0 2.0 6.38 10.18 1.800-1.855 The equation for stroker math: piston pin height = deck height - (rod length + crank stroke/2) Buick 300 with 340/350 crank: ---------------------------- deck height - (stroke/2 + rod length) = pin height 9.5 - (3.85/2 + rod length) = 1.8 rearranging and solving for rod length to use Buick 340/350 crank and pistons in a Buick 300 block: RL = 9.5 - 3.85/2 - 1.8 = 5.775 or RL = 9.5 - 3.85/2 - 1.855 = 5.720 Small journal SBC rods are 5.7" which is in the ballpark (deck block 0.020" if required). I think the stroke limitation is likely to be the rod bolts coming too close to the cam so this would all have to be mocked up and checked. I have an article about a 340 crank in a Buick 215 and also Kurt Schley has a 3.75" stroke M/T crank in his Olds 215, so I believe it is possible. I don't know what the 350 pin diameter is so they may or may not work with the SBC rods. If you choose a different piston with different pin height, you'll need a different rod length. The Buick 340 and 350 cranks are the same, the difference is bore. The 340/350 crank needs to have the mains turned down from 3" to 2.5" to fit the 300 block but that's not a big deal. With 0.050" over pistons, you'd have 350 cubes. I think the area of main concern is rod bolt to cam interference." So it looks like theoretically my SBC rods would work in a stroker 300, with stock 340/350 pistons if the skirts would clear the crank. There's 0.670" difference in rod length. Dan thinks forged pistons would be the best route. He may be right, but I'll put off that decision. D&D cut the skirts on their stroker. Sean, that link was *Awesome!* Now if there'd only been some 300 and 340 block pictures... but even without, the head and rod shots sure help put it all in perspective. That P76 intake has me thinking (dangerous, but too late now), Wonder what the stock intake looked like? See, what I did for the blower setup was to build a plenum or riser between the blower base and intake which gave me a place to put the intercooler and got the blower up above the fuel rails. The intercooler extends down into the intake plenum and there's a thick flange welded on for the riser to bolt to. The intake is an Offy dual plane with all the internal dividers removed, and the reason I used that one is because it had the largest plenum, which was just barely big enough. With a wider intake there may be more options. For one, with the fuel rails moved out there is more width, but that doesn't necessarily mean I can lower the blower any because of the angle the intercooler works at. However it'd sure make the rails easier to work with at the very least. The big thing would be to see how big the plenum is. Guess I need to go looking for a photo of one. Well, that's the biggest problem with the 340 short block. I am pretty sure I can put slight bends in the header tubes to match up, using my welding bench and an old steel 300 head I have, and that's an attractive option if I can stay pretty close to stock. With a 300 block there's less work on the intake and exhaust but more on the crank and pistons. Also since D&D had to grind the rod bolts to clear the cam and the pan, it makes me wonder if the interference with the SBC rods would be more, or less. Could be a problem there. Looking at the heads I see what Dan was referring to with the water passages on the steel heads and intake. Looks like you could use a steel intake with aluminum heads but not the other way around. The ports would have to be matched, but it looks feasible. Not that I'd want to, but if that's the only difference there should be no problem using the '64 heads on the later blocks. When the weather clears up I'll start beating the bushes for an engine. By then I hope to have decided which one to look for. That intake could make all the difference though so I guess it's time to contact some of the aussies. Jim
Better than picking my nose. I have been building an Excel sheet listing displacement, bore/stroke, rod length, deck height, combustion chamber type, etc. of every (Domestic) OHV engine I can think of. I've worked on it on and off for a half-dozen years, and at this point, I think I have it about half-done. In fact, I spent yesterday updating the Chrysler Polyspherical section... That was supposed to be background information for a book I wanted to write. But since I'm having so much trouble finding the info myself, I don't suppose I'll ever get the book done. So, yeah--ask away. If I know the answer, I'll tell you.
Jim, Rerun those numbers for the SBC rods. I don't think they will fit. In that monster motor article you linked to us they used the stock 300 rods (5.96) and still had to releave the pistons. I don't think the SBCs will work... All the references I found put the 300 deck at 9.54. I know 40 thou might not add up to that much but better to have it right for calculation sake... The Jeep pistons they used have a compression height of 1.632 or 1.581.
Oh well, I'm leaning towards the 340 short block anyway. I dug out the heads and intake and had another look and I don't think it'll be that bad to make up the spacers. Of course that'll raise the blower up about 1-1/2" from where it is now, making the hood a little more tricky to open, but I have work to do on that anyway. I'm really thinking that'll be the best way to go. Probably have to trim an accessory boss off the back of the driver's side head, but don't see any other problems, except... How did they deal with the different strokes when it came to engine height? Just leave more space under the smaller engines, or locate the mounts higher on the block? Jim
I think the area of main concern is rod bolt to cam interference. exactly correct. the 340 / 350 are considered maximum possible stroke for this block design because of interference with the cam. anytime there's a rod failure with one of these engines it almost ALWAYS results in contact with the cam and a destroyed block. cam to crank spacing is the same from 215 to 350 and all of these engines as well as the Buick v6's and Rovers can swap timing covers. How did they deal with the different strokes when it came to engine height? Just leave more space under the smaller engines, or locate the mounts higher on the block? eh? all added deck height adds to how tall or short the engine is in the bay / subtracts from hood clearance. clearances from the engine mounts to the front crossmember are the same no matter what block you're working with. think of it this way; the engine mount to crank dimension is a constant. it's the crank to the top of the aircleaner that's changing.
True, but I'm concerned with the distance from the crank centerline to the OD. As the stroke increases this distance increases so with the 340 crank it's 1/2" more than with the 215 crank. Guessing that the crank to pan distance on the 215 was some standard distance, using the same distance with the 340 means the pan has to be 1/2" lower or the crank has to be 1/2" higher. The motor mounts could determine which way it went. If they stayed at the same position on the block the pan goes down 1/2" For me that would be an issue I'll have to deal with by modifying the engine mount standoffs, basically moving the engine up another 1/2" to get clearance. Does that make sense? I probably have less clearance under the pan than factory cars do. Jim
That makes perfect sense, Jim. Buick left plenty of room in the cars these engines came in. We run in to the same problems you are having when building the Vega. When my 215 was swapped in the actually cut a notch out of the pan, reducing the oil capacity, to clear the crossmember. There is currently enough room in my spare (unnotched) 215 oil pan to clear the extra 0.3" increase in crank centerline so I'll be using that one. I could have technically used the notched pan that came with my Vega but I don't particularly like the idea of reduced oil capacity (not quite 4 quarts! DUMB), and I am converting from a gearbox to rack steering. I needed more crossmember support so I'm building my own out of mandrel bent tube. The stock crossmember in the Vega was made of toilet paper and bolt in to aid in easier plant assembly. It's totally worthless. I don't know much about the MGB but the crossmember clearence is a factor to consider. I'm pretty sure the only reason I would caution against raising the engine is adjusting the pinion angle. Also the intake level but that isn't a factor for you. I'm planning on fabing my own headers too. Do you have any advice? So the cam to crank distance is the same for the SBB? I always assumed that the 340 and 350 had to raise the camshaft... Thanks for the info, Bob.
IIRC the crossmember isn't quite as much of an issue as the steering rack on my car. At one point the rack dented in the pan enough to cause the rods to hit, but I raised the standoffs after that. Looks like I'll have to go more. I think the newer conversions move the engine back and down and the rack is just enough forward to clear. Nick, what I did was to buy parts from "Headers by Ed", Ed Henneman: https://www.headersbyed.com/ Quality parts and comprehensive instructions on all aspects. Can't go wrong there. Also, some header manufacturers sell kits. For measuring the runners you take the outside length, the inside length, and the average is the actual tube length, but you have to do each bend separately and add them up. I incorporated swirl scavenging in my collectors by using the firing order to arrange the tubes. Ed was very helpful in deciding tube diameter, length, and collector diameter. It's real easy to go too big. Jim
That's cool. I'm really impressed that you were able to get the lengths so close. That combined with the overall length (as in 'Long' headers) must make them really perform well for you at lower RPM. Ed's shop is near me in MN! I was planning on buying his header flanges. THey look really nice. I think he's got a really nice website info wise. A little tough to navigate but informative. I was wondering about some things like how do you weld the collectors on? I can't figure out how you get the welder into the middle... Did you use a MIG welder? Thanks for the input, Jim.
I had a built Buick 215 with the hottest cam I could find (hydraulic) and a 600 holley double pumper, and it just SCREAMED up to 7 grand which was my redline. The primaries are 34" which is just about right and 1-3/8" diameter. The blown Olds 215 has valve spring issues (don't they all) and won't rev very high but it doesn't seem to be at all limited by the headers. I think I'll get as much power out of it as I want with the 340, even if the tubes do turn out to be a smidgen small. Jim
For me that would be an issue I'll have to deal with by modifying the engine mount standoffs, basically moving the engine up another 1/2" to get clearance. Does that make sense? ah, i understand your issue. how about a 3 or 4 stage dry sump system? you can practically eliminate the oil pan and it functions as a vacuum pump for the block at the same time. less oil aeration, cooler oil and more consistent pressure is just icing on the cake.
Some photo's to slog about in your brain... Pic 1: Stock 340 intake next to an Austrailian Wilpower P76 intake with adapter plates. Pic 2: Stock 340 intake next to Australian Wilpower P76 intake with no adapter plates. Pretty close but needs help. Pic 3: Stock 340 intake next to Australian Wilpower P76 intake with adapter plates. Pic 4: Stock 64 300 intake gasket on the P76 intake port. If you're going to use 64 300 heads... it could be made to work.... Greg
Nick, what you do is weld the centers of the tubes first and then slip the collector over and weld the outside. It's pretty easy that way as all you have to do is hold the tubes together (a big hose clamp might work) and then heat the tubes and pinch them together in the middle with vise-grips to close the gap. It helps to tack them together first where they touch. Then you just weld the edges together and remove the clamp and the collector is ready to go on. It'll be obvious once you're doing it. Another thing is that if the tubes don't come out exactly right on length (which is difficult) you can be off a little and have staggered ends inside the collector. Don't want too much though as it'll be hard to get the collector on. A couple of options here. Depending on tube size and room between them there might be room for a vacuum tube for the crankcase, or even a fitting for O2 or EGT sensors. But if you do that make sure to use plenty of the best available anti-seize on the sensors cause they'll be a little hard to get to. At this point it looks like my best bet on the intake is going to be to make up some spacers for the 215 blower/port injector intake I'm using now. I'm still a little concerned that the bolts don't seem to go through at a 90* angle but I should be able to deal with it. In those photos they don't look as steep as I remembered. The spacers will have to be 1.190" thick if the manifold flange is at the same point on the 300 and 215 heads relative to the bore centerline. I sort of hate to add that much height but it looks like the easiest way to get acceptable results. A dry sump doesn't buy me anything because it's the rod to steering rack clearance that is the issue, not rod to pan. I could maybe adapt the blower to a Wilpower intake but I'd lose the intercooler in the process. On the heads I figure I'll just put oversized exhaust valves and maybe lightly port the exhausts but leave the intakes alone and use a stock cam, but most of the component selection can wait until I get a short block. There may be lots of things there I will re-use. Speaking of that, is there a stock short block that would give about 10:1 compression with the 300 heads? I have heard different figures for chamber volume. Is 54cc correct? If a stock short block will work I might be able to find a reman at a reasonable price. Also am I right in thinking that a 215 pan isn't going to fit the 340? Jim
Wish I had some coin... http://cgi.ebay.com/ws/eBayISAPI.dl...MEWA:IT&viewitem=&item=290077698240&rd=1&rd=1 About $3400 worth of alloy... Greg
Thanks, that helps. So the plan is to go with a 340 short block, '64 300 heads, and the existing blower intake with spacers. I need to cc the chambers and spend some quality time on piston selection, but there are plenty of choices. There are also reman short blocks available, and as I'm not building a race engine they can be considered. So on to head work and cam selection. The head work is going to be asymetrical because of the blower and although this runs counter to conventional wisdom, I've already explained the reasons but if anyone wants more clarification I'll be happy to go over it again. Suffice it to say that the inlet tract is being used to restrict high rpm boost and keep cylinder pressures in check, and with boost levels being adjustable with a belt and pulley change, I'm inclined to leave the inlet side alone. Exhaust is an entirely different matter. I want to get the exhaust out of the cylinder as efficiently as I can, so I plan to fit oversized exhaust valves, do whatever amount of porting seems most appropriate, and with the good headers I already have I think I should get good results. Exactly what type of port work I don't know yet, but I'm assuming a cleanup below the valve seat, a little work on the guide, and a general smoothing and blending without removing any great amount of metal from any one area. Any tips or tricks here would be most appreciated. And that brings me to cams. I'm not that familiar with what is currently available for these engines, so I'm looking for help with it. My thinking is that I need a mild cam that is balanced towards exhaust flow. Is anything like that available? Thanks. Jim
Well it turns out I'm going to have to look for another 340 block, the rust had gotten to this one. Everything was fine until they turned it over to magnaflux the crankcase and found a hole into one of the lifter oil galleys. I stuck a flashlight in the lifter bore and saw a bunch of itty bitty light specks around it too. No way that's going to hold oil pressure and not a good place for any kind of weld, braze or patch. Too bad, the rest of it was fine. But, just goes to show why a proper cleaning and magnaflux is a good idea. I could just see building that engine without finding that. It'd never have good oil pressure and I'd never find out why. Kind of a bummer but worth the money to find out. Looks like I'm putting out feelers again for another block. Jim
