Just want thoughts from bigger brains than mine before I spend big. I have: 75-76 block, chamfered main feed holes, radiused 90* turns near pump Std bore, Wiseco 22cc forgings Stock rods, resize w/ arp hardware Crank turned and assembly will be balanced Big valve 430 castings from a fellow member 1 7/8 headers Most likely will go b4b if not just for my back. I calculate static at 9.7:1 with my deck height and gasket. I'm looking for a 425-450ish hp motor I can cruise around without having TOO much fuss, but I also don't mind knowing it's not stock if that makes sense. I've been eying the ta 284-88h, as it seems it should make good torque, and pull to up around 51-5200. I also figure this combo should, provided the machinist hits the marks, be safe to turn around 5500, so that seems like a good match. Does my thinking make sense on this? If no, what rpm should I be sure to keep it under, and/or which direction should I go cam wise?
Based on that head flow, I’m thinking you could go for an even bigger cam. Worst case scenario you deck the block or cylinder heads or pick a thinner headgasket.
The TA 284/88H will put you at 7.55 Dynamic compression with 9.7:1 static. The TA 290/94H will be 7.23 DCR Go with the smaller cam. 425-450 HP, it will depend on the heads.
I have cometic gaskets already so that's as thin as it gets for the late block, so 9.7 is where we're locked in at. Heads are said to flow 251/187 I believe. 3.50 gear and a 275 tire Larry. The th400 will be gone through, and probably get a converter from TSP at some point.
275/60R-15, or 275/50R-15? One is 28" tall, the other is 26". The taller tire will give you less gear (~3.32), the shorter one, a bit more (~3.58)
Spend good money on the right converter. Do it before you swap the new motor in. Have you measured the deck height?
275-60/15, my bad. Gear change isn't impossible, especially being a 9 inch. Got .085-.087" to the stock 75-76 pistons which should be 1.935 pin height iirc. Have not measure with new pistons but they are 1.980.
Plan was to match converter and gear if need be to the motor, so good to hear I'm at least headed the right direction. Just wanted to be sure I'm not too optimistic about rpm and the likes.
To answer your rpm questions I would build it on the tight side to keep oil pressure up. .002 on the rods and .0025 on the mains. Make sure the oil pump is perfect and 5500 will be fine. The wisecos are kind of heavy so i wouldn't go past 6k. With the right converter it'll run good. 450 hp is optimistic with a mostly stock build though.
Unless the machinist misses his marks that's what I should have. The timing cover looks really good so I was just planning on getting a standard volume pump set up perfect and uing the adjustable regulator. Perhaps I've been reading too many magazines on the number, just seems to be several running good times with less compression on small valve heads so I got a little optimistic
What about the 288-94. They call the sleeper grind. 230-240@ .050 504/504 lift. 114 lobe centers. Idle nice and rip. Never know who you may pull up next to. Might have to take em down, lol. Lot of fast stock cars out there now and our Buick’s need to showem who’s boss.
Larry heads are quoted to me as flowing 251 cfm intake and 185 cfm exhaust. I can't prove it as I don't have them yet but they are supposed to have been in the 11's on the previous engine. It's worth noting that if I get 400 or a tick over out of it I will be happy with it, just been reading about similar builds making good numbers (perhaps a little fisherman storytelling) got me wondering if I was on it with cam selection etc
251 can make some power. The question is at what lift? I would assume thats the peak number at max lift it was tested, probably .600. Your cam is .475 lift, so you will not see 251 cfm.. obviously you can swap a higher lift cam but you'll need more compression to make that work. The other option would a custom roller cam with a high lift and short duration. I would either add some compression or run a small cam and focus on the mid range.
You may well be correct on that as I don't have numbers for specific lifts. These are the 109's that Ol Blue just had for sale on the board, off a 470 from Steve Reynolds's 70 gs. Porting was done by TA. I've not been here long enough to know anything about the car or the engine other than that.