Everyone has their own ideas about the best way to build an engine but since I'm building a 340 I thought I'd start a thread. You other 340 guys, feel free to hijack away. It seems to me the heart of any 340 build is going to be the pistons. Once that decision is made, everything else flows from that. In my case it was a tough choice because I had a fresh reman short block with 10-1/4:1 cast pistons and the sensible thing seemed to be to just use them. I would have too if the rods hadn't been such a mixed up mess. But since they were I began to look at options. Somebody suggested Venolia for pistons and when I called them they gave me a price of $73 each and I thought that was reasonable enough to go with. Rods to go with those turned out to be $359 a set for aftermarket forged H beam flathead ford rods that use the V6 Buick bearing shells and are 7" long with a 3/4" piston pin. They are Scat brand with 7/16" ARP bolts, I just hope they clear the cam. If all that works out the bottom end should be pretty bulletproof for a street engine. I'll drill out the oil pickup journals, use neoprene crank seals and maybe do a little work on the front cover if I get energetic. I've heard relocating the cam bearing oil passages is a good idea, don't know if I'll do that or not. As far as the block, it's .030 over and looks fine, but the yahoos who did the rebuild boogered up the cam bearings and apparently grabbed the wrong bucket of main caps because the fit is just a little off. So I don't trust anything else they did. I'll have the block align bored, decked and honed square with the crank, new cam bearings natch, and probably need to sonic check it since it'll probably be at 350 bore size by the time that's all over. If I manage to build the short block for under $1800 not counting the cost of the reman I'll feel pretty happy about it. The heads meanwhile are finished. They are a set of '64 300 aluminum heads with new stock size valves, bronze lined guides, teflon seals, and the springs Comp Cams used to sell with their hottest hydraulic SBB cam about 20 years back. I seem to have misplaced the specs but they handled 7 grand just fine in a 215, we'll see how they work in these heads. With about 20K miles on them and then sitting for years with only seated pressure I think they'll be fine. That pretty much leaves exhaust and intake, and the exhaust is a set of custom fenderwell headers with 1-1/2" x 32" primaries equal within 1/4" on all 8 tubes, dumping into 2-3/8" by about 20" collectors and then into glass pack cartridges and out the side. The intake, also custom, will be an Eaton M-112 blower off a Ford Lightning truck, with port injection controlled by MegaSquirt and most likely an intercooler of some sort, though not necessarily the experimental heat-pipe IC that is on the 215 in the car now. Static compresssion will be a little over 10:1, most likely MLS head gaskets will be used, especially if I can find them in stainless at a reasonable cost, but there's also a neat pressurized tubing ring that can fit just inside the gasket cutout that I want to look into. I think they are *very* expensive though. Valve covers are Rover cast items, and boost will be limited to something in the neighborhood of 8 lbs, just to get enough pressure to overcome the restrictions of the aluminum heads at higher engine speeds. The cam will have a mild grind on the intake side and an aggressive exhaust lobe with minimum overlap. Not sure about the lobe separation yet, and the engine will go in a 2500 lb car with a 2004r automatic and set up for road courses. This I think will be a pretty potent package, so there's the plan. At this point there's not much left that is subject to change and the plan is to have the 340 finished next spring sometime. I don't expect the engine to be any 700 hp drag motor. I do expect to exceed 300hp by a bit and be capable of 7000rpm, with good durability and very good economy. Some day when TA makes their SBB heads I may even consider a set of those if I have won the lottery by then. So that's my plan, what'y'all think? Jim
Jim can you explain how you will set up the blower. What will that sit on. What will you have to fab up??
Actually with the aluminum heads I'd like to be up around 11:1 but we'll see. Olds did it with a turbo, no intercooler and 6lbs of boost, but they also used water/alcohol injection. Still, if it worked for them... The intake will be the same but different. Since there's no aluminum intake to cut down I'll have to build that out of plate but that's probably a good thing, more flexibility that way. The base on the M112 is wider and I need that for the intercooler but I still haven't run the datalogs to see how well the old one is actually working so it may or may not use the same experimental design. Also the M112 has a better inlet, an oblong opening at the rear that faces straight up. That will make fabrication of the enderlie style scoop/throttle body a lot easier. I may or may not angle the port injectors. A few years back pointing them at the valve head was all the rage but maybe not so much now. I haven't heard much about that lately, maybe it doesn't make that much difference. One thing for sure, vertical is easier to package. Jim
I agree with Sean.I think static compression should be 8 maybe 9 to 1. It's better to have lower static compression then use more boost presure. How are you going to adjust the timing when the boost comes in?
If I was building a drag motor I'd agree. But I'm not. I've run lower compression (doing it now in fact) and what it does is reduce economy and reduce torque coming off idle, both of which are a big deal in a daily driver. So in this case I think it's better to run higher static compression and lower boost. Fact is the car wouldn't be underpowered even without any boost, but my entire purpose with the blower is to overcome the breathing problems of the '64 heads. Well that and maybe add a *little* power and extend the rev range a bit. Timing is easy. The MS-II allows me to map timing on the fly so with the wideband O2 and EGT I can get pretty close. Pulling advance is just a few clicks away. I'm running a crank trigger EDIS so I'll carry that over to the new engine. I've not noticed any misfires under boost so it must be working pretty well, the 215/M90 runs 16lbs+ at full tilt-n-boogie. Jim
Guess I must have missed the post button after the preview. Oh well. The rods came in and they sure are purty. But there are three issues. First, they don't have an oil spurt hole to spray the cam. I think I can drill a hole across the parting line and through the alignment tube and fix that, say about 1/16" or smaller. Second, there is no oiling hole on the top, but a center drill would fix that. I'll have to look at the stock rods, I can't remember if they had one or not. But the big issue is interference with the cam. Has anybody dealt with this? I'd think that with some of the big cams you 350 guys are running it would have come up. How much clearance is needed? I'm finding that the shoulder of the rod just grazes one of the cam lobes. I can grind back the shoulder but it seems like that would limit my cam choices a lot since this is on a stock cam. Anyone have advice on that? Photos below. Jim Well, there were going to be photos, not now I guess. Something about an upload in progress. I can't fix that.
Yeah, I guess so... Anyway I made a mistake on the top oil hole, it's there. I guess they do that when they bush the top hole for a full floating pin. One down two to go. Next, maybe I can reduce the base circle on the cam to get clearance and a little more lift. I have a 1.020" minor diameter, 1.175" base circle, and .250 lobe (.400 lift at the valve with 1.6 rockers). If I reduce the lobe .030" I think that may be enough clearance (any recommendations for that?) and that leaves maybe as much as .090" for extra lift x 1.6 = .144 or .544" max lift which should be more than I'll need. If I stay at .500 lift I can go .050" clearance at the rods. Sounds like 2 down and a fairly easy 1 to go. But of course I still have to do more measuring and checking. Jim
It turned out that I had to clearance the rods due to interference with the cam lobe at cylinders 6 and 8. This got me enough clearance to miss the cam but for a running clearance of .050" I'll need to use a reduced base circle cam. as I expected. I cut the corner off the shoulder of the rods and chamfered the rod bolt on that side to clear. The big end is .023" too thick but I'm going to let my machinist trim them down as well as honing to finish size (a required step with Scat rods). The last step for me before sending the block, crank, rods, damper, flexplate and cam out is to drill the oil holes for the cam bearings into the driver's side oil journal. Oh what fun that promises to be! Jim
The new holes are now drilled in the cam journals. Only the rear four needed drilled because the oil from the pump is passed to the passenger's side through the front bearing using the groove in the front cam journal. This is a tricky job because you have to start the drill on a curved surface and there is nothing to give the bit any "bite" in any direction due to the angle you have to come in from. At first I thought I might have to make a drill jig to locate the bit in the bores, but each bore is a different size meaning I'd need 4 jigs and that's a lot of machine work. But after pondering the problem awhile I realized that the old cam bearings could do the trick for me. The first thing was to get a drill at least 12" long. There's a hardware store a few miles away that has a decent selection of bits including long bits, but the Ace hardware around the corner had a 16" Irwin wood bit and I decided to try it. Irwin uses fairly decent steel, at least it's an alloy rather than some of the carbon steel bits. Not what you'd normally want for metals but maybe good enough. Next step was to reshape the cutting edge. I'd need a very pointy tip if I was going to be able to hit the oil journal, and it would have to cut all the way to the center because I wasn't going to be able to apply any pressure to start it or it'd wander. One of the photos below shows the tip I ground after it'd drilled the four holes. Not very pretty, I can do much better but I wanted to see if it'd even cut so I rushed it a little and then when it worked I just went ahead and finished the job. The next step was to drive in the old cam bearing so that the oil hole was just a little uphill from where I wanted it, and about 3/32" shy of center. The idea was to start the bit in the old hole in the bearing and cut through that into the cast iron but what I found was that if the shell is rotated too high the bit will skip right through the babbit as if it wasn't there, so the position needs to be just right. If it is, the edge of the hole will hold the tip of the drill just long enough to start the hole in the block and then it's a clean shot into the oil galley. You can see how the holes came out, nice and clean and properly located. I had other issues with this block, the rear plugs were installed by a blacksmith and the block had to be heated with a torch to remove them. The locating dowels had been driven all the way in by dropping the block on them and even with heat and prybars one of them would not come out and the block gave up first, meaning a weld repair. Luckily I'm a pretty good hand with nickel rod so the block was saved. So in the final analysis, all I got out of this reman short block was a block with mismatched main caps. The crank and rods were bad and I'm not using the pistons or cam. Not such a deal. Luckily the seal will line up OK in the rear main and the #3 cap can be tapped all the way to the rear and get the parting line flush. But it will definitely need align bored. I've got it all boxed up for transport to Dale Spooner in Danville VA. I really appreciate the local recommendations and would have used them, but I've known Dale for long enough to be really comfortable with his work and a means of transport became availabe so I decided to stick with him. In the meantime I have to swap engines in my MG. Seems little brother didn't know what an EGT gage was for and holed a piston. Luckily I have a spare 215. Guess I should have told him but I didn't even think of it. Jim
Hey Jim, the stock horsies on a 340/4 was 260. I would think you would be well over 300 horse with what your doing. Over 400 probably??? It will be interesting to find out when you're done!
Dale Spooner in Danville, Va has the parts and is doing the machine work. The crank journals were out a couple thou sideways and the rear main cap was off a different block but he got that to clean up with only a narrow strip by the parting line of one of the caps not cleaning. Dale's very meticulous so I think we're good there. The decks had been machined (poorly) by the reman shop so he cleaned those up, squared them to the crank and gave them a finish suitable for the MLS gaskets I plan to use. The bores cleaned at another .020 over the reman's .030 overbore so we're at 3.850, same as the 350. 10.8:1 pistons are on order from Venolia. Three weeks delivery. In the meantime I need to order head studs, seals, and head gaskets. Probably give TA a call tomorrow. I have an email out to Cometic about the head gaskets. I'd prefer to use them over Gaskets-to-go since they are sort of local and the other guys are half way around the planet. But we'll see. Maybe TA can help with that, maybe not. I seem to be rough on head gaskets and reciprocating assemblies. Hopefully the MLS gaskets will take care of one and the rods and pistons will take care of the other. This engine is going to be pushing the envelope a bit (like about everything else I do it seems) with the high compression and the blower, but I'm counting on the urban legend that an aluminum head is good for 1 point more on the compression which would make it comparable to a 9.8:1 iron motor. I don't totally believe that, which is why I didn't shoot for 11-1/4. For the blower to work well and not blow up the engine, I plan to limit it to 8-10 lbs of boost and use alky injection and an intercooler. The alky system will be a direct pressure setup where pressurized air from the blower forces the fluid from the tank into the blower inlet. Obviously flame traps will be an absolute necessity. I haven't ordered a cam yet and need to find some good knowledgeable blower people to talk to first, hopefully someone open minded since it isn't going to be a drag motor. The cam is the key to not blowing the engine up. The goal here is to maximize the torque curve, while increasing the redline to somewhere approaching 7K. The horsepower peak can be around 6K or even lower as long as it does not drop off a cliff at that point. I don't mind a power drop up high, and here's the scenario. Say I'm exiting a long sweeping decreasing radius curve, pedal down and winding past 6K with more curve to go. Obviously I don't want to let up. Just as obviously I don't want to shift gears just yet. I'd much rather be able to run the engine right on up to 7K while I'm getting the car straight and Then shift where I don't have to worry about the shift throwing the car sideways. It's not like the 1/4 where you get to shift wherever you like, it's more a matter of holding your line. There's more that goes into it. It's not a bad idea for the cam to limit the top end. With the gasket problems I've had in the past I'm not real anxious to keep blowing head gaskets, and my HP goals are pretty modest. The car only weighs 2400 lbs after all. With 300 hp that's 8 lbs per HP (about what I was getting out of the 215) and it's very fast, except when Dan Jones sits his 260 lbs in the passenger seat. With 400 it would be about 6:1 and I'm not at all sure a street driven car needs any more than that. At least for now, I don't. How that may change once I have driven this new combo awhile I can't say, but as we all know horsepower is kinda addictive. Jim
> I'm counting on the urban legend that an aluminum head is good for > 1 point more on the compression which would make it comparable to a > 9.8:1 iron motor. I've heard it attributed to heat transfer to the coolant. The aluminum head retains less heat so can tolerate higher pressure. It's the old ideal gas law: PV = GammaRT I've also heard it claimed that aluminum heads don't have the localized hot spots that iron heads can have. > I don't totally believe that, which is why I didn't shoot for 11-1/4. I've wondered what happens when the chamber gets carboned up. It might be worthwhile to look up the heat tranfer for a thin layer of carbon. > use alky injection and an intercooler. You might want to get a look at the research Sir Harry Ricardo and company did with water/alcohol injection for WWII fighter plane engines. > I haven't ordered a cam yet and need to find some good knowledgeable > blower people to talk to first, hopefully someone open minded since > it isn't going to be a drag motor. Let us know what you come up with. > With the gasket problems I've had in the past I'm not real anxious to > keep blowing head gaskets, and my HP goals are pretty modest. My buddy that ran the high boost street Buick Grand National V6 refered to the head gaskets as fuses. They are meant to pop and save the expensive internals when cylinder pressures or detonation gets out of hand. > it's very fast, except when Dan Jones sits his 260 lbs in the passenger > seat. Hey now, don't blame your engine's inadequate power delivery on my petite self > How that may change once I have driven this new combo awhile I can't > say, but as we all know horsepower is kinda addictive. Too much is never enough. > With 400 it would be about 6:1 and I'm not at all sure a street driven > car needs any more than that. On my next engine, I'm shooting for 550 HP in a 3000 lb car. That should be sufficient. I've driven a 2200 lb car with 550 HP and it was a hoot but my passenger was petrified. Dan Jones
Hey Jim, I have a stock 340 SBB that i would like to have re-built. Do you know of any good literature/videos that i can find on this engine? I would like to do it myself just so i can get my hands used to working on this engine more than i have previously. Thanks. Great thread!!
Sorry to not respond sooner but I don't have any real leads on videos or literature. There's a specifications page somewhere though, might try a 340 Buick search. The pistons just arrived at Dale's shop, so the bores will be finished soon. I ran across my copper head gaskets from the 215 and since the cost to O-ring the block is a couple hundred less than the cost of MLS head gaskets I just told Dale to O-ring it. I'll use "Right Stuff" sealant around all the water and oil passages and that should do the trick. The bore holes will need to be opened up to about 3.870" or near thereabouts but I can make up a punch and die set and do that in the press easy enough. There are slight differences in the 215 and 340 head gaskets but it doesn't look like that will pose any problem, and with the O-rings the copper gaskets should seal a lot better. I'll probably put some right-stuff around the bore holes too just for extra insurance. Piss on that idea of using head gaskets for fuses, if I want a fuse I want it to be easy to change. Looks like it'll be about the first week of December before I will be able to get the engine transported back here, but the good part is not having to pay shipping. Can't beat that. Jim
Good update! Now when you have a chance please take a few pics of the veniola pistons and post them. Are there valve reliefs in the pistons, and how much do they weigh? The diamonds I am using are 555 grams and the TRW pistons I was using before were 702 grams, not sure what stock weight was though...
The machine work on the engine is finally all done. The cam bearing bores had to be honed out as they were undersized a couple thou but at least the bores were in a straight line, that was the reason for the carved up bearings in the reman. Dale surmizes that worn out tooling was the cause and the factory may have finished the cam bearings in place. Anybody know? We o-ringed the deck, narrowed the big ends on the rods, and it turns out the balance on the rods themselves was exceptionally close, within a couple tenths of a gram. This even after I had whittled on them for clearance. So everything is on schedule and I should be seeing the parts in two weeks. Can't wait. In the meantime I'll try to get the lathe freed up so I can start making those dies for the head gaskets. I'll take photos of everything once it gets here and see if I can get those piston and pin weights. The rods were the same weight as stock, but of course they are a good bit longer. I expect the pistons to be lighter, how much I don't know. But they are street blower pistons so maybe not a whole lot lighter. We didn't cut eyebrows in them, at least not yet. That will have to wait until after a cam is selected, and probably ground. I am leaning toward a mild grind on the intake, a fairly radical grind on the exhaust, and minimal overlap, in order to work well with the blower and produce good economy. Can anyone suggest a cam grinder who would be good to work with on that? Jim
