As I wait for my TA aluminum block, I'm trying to figure out if I should build a 470ci, or a 535ci. I already have a brand new, never run, Moldex billet crankshaft,3.955 stroke, wrapped in plastic and has been safely stored for about 5 years. I also have a set of 7 inch GRP rods (chevy rod journal) that I had checked out by GRP about 5 years ago. And a set of JE pistons, .038 over ( 14 to 1 comp. I think)for the 470ci motor. The short story is that I had TA build a shortblock about 7 years ago, It ran great until I lost my oil pump drive, found the crank cracked on almost every rod journal radius, and then found many cracks in the block. The initial rotating assy. was bought from Mike Phillips at AM&P, and I bought the Moldex from him too. So can I use the pistons and rods with a 4.50 stroke crank?? Or would I have to sell the whole rot. assy. and get different rods, and pistons, either way I go, this motor will be built for a pretty good size shot of nitrous... I may need some more nitrous friendly pistons over the JEs. I don't know the pin height for the pistons, I'm guessing that would be helpful, and would the 7 in. rods be too long?? Thanks, Gary G.
I don't know if this will help much,but Mike built my 523" streetmotor(10.4 comp). It isn't a race engine,but we use 7.1 Eagle rods and JE pistons. It peaked at 657 HP and held 650"s for @800rpm(to 6400rpm). I think that size matters. My engine is on his website. Just my opinion. Mike Nussell
Was that a subtle hint?? I may, just not yet..... I need to know if the rods, or pistons would work with the 4.50 stroke..Ya know those crankshafts are NOT cheap! Gary G.
Gary, I would say that you would have to get new pistons, along with the new crank. You can figure it out for yourself. 1/2 the stroke, plus rod C-C length plus piston compression distance= Block deck height. That will tell you what the deck height would have to be. but it's very unlikely that pistons and rods that were designed for say a 10.550 deck height and a 3.995 stroke would be able to be used with crank that is half an inch (effectively for the formula .250) longer. Here's an example with your current crank 1/2 stroke (1.9975) + rod CC (7.0) plus compression distance (guess 1.550) would mean that you need a block with a 10.547 deck height.. or about .025 cut off the stock block with a 4.5" arm.. Now change the 1/2 stroke number to 2.25 and the same parts require a block with a deck height of 10.800.. The stock TA alum block is the factory 10.570. Your pistons would be hanging out of the deck by .230.. :rant: :shock: Now plug in the correct compression distance for your particular pistons, and you can see what deck height that you require, and what you can and can't change. The big strokers typically use that same 6.995 long GRP rod, but use a piston with a 1.350-1.400 compression distance. Compression distance will vary with the stroke. The last one I built was a 4.400 stroke, used that same rod, with a 1.365 piston.. so it needed a 10.560 deck height, or just a .010 cut off the block, for zero deck. At 4.375 bore, it was 529". The big motors will make substantially more torque, and with good enough breathing, equally more HP, than the smaller ones. Is it worth the extra money?.. with boost or N20, I might say no.. as you have other options for making power, but if it were to be naturally aspirated, then I would say yes. JW
Thanks JW. I'm just trying to figure out how to use the new block more effectively, and still have room for boring / rebuilding, if something bad would happen. I would think the 470ci with internal bal. and aluminum rods could be a higher reving motor, and my stg. 2 TE's wouldn't be as much a restriction compared to putting them on a 500+ ci motor.. And the nitrous, I'm planning on getting a fogger unit, so that could be 300 horse or more, I could keep the plate unit I have now, launch the car on say a 100-200 shot, then add in the fogger, or just run the fogger, one unit, equals less hastles. I'm thinking the 470ci with 14 to 1 comp. could be around 775+ horsepower, add in the nitrous,whatever it could take, I want 8.50's or damn close in my 3500lb. car. Gary G.
With a 4.4 bore and 3.955 crank you have 481cui. That's a pretty nice spray motor. Can still bore several times.
if your thinking of the 535 do it once and do it now. if not you probably will do it in a couple of seasons anyway.
What you have for heads matters. IMHO unless they flow enough the extra 65 inches may not return what you think. I have a 526 (another brand) in my garage that I took out after 10 runs. I didn't have enough cylinder head on it, despite 80 xtra cubes I gained less than 2 tenths on the track because the heads were maxed out.
