VAformula

iTrader: (8)

Hey guys, It's me again with more questions. I'm used to big blocks mostly but I love my F-Body to death, (maybe more than my Chevelle).

I have a 355 that I'm building with an AI cam (228/234 @.050, .612/.612 111LSA) with dome pistons and a 12:1 CR. I also have 200cc CNC heads on there.

I have all my bolt ons (exhaust, cai, underdriven pully, etc) and I have a 3200 stall and 3.73 gears.

Now my questions, do I need to get my intake bored and how much? I plan on using a 52mm TB and 30 lb injectors, I know that the intake is 52/54 stock (I've heard both numbers) so if I'm using just a 52mm is there any point of getting it bored to 58?

Thanks!

SS RRR

iTrader: (2)

You don't have to get the intake bored for a 52mm. I've always read the bores are 52mm.

bowtienut

iTrader: (1)

Yep, you're good to go with a totally stock intake manifold.
You're going to love that setup.
Similar to what I have in my SSled

VAformula

iTrader: (8)

I really really can not wait to put it together, I blew a head gasket and decided to let it sit for two years as I completely rebuilt my Chevelle from the ground up (was caught in a fire) and now I'm trying to get a good build, what numbers were you pushing if you don't mind me asking?

bowtienut

iTrader: (1)

Dyno'd 425 SAE @ 6400 rpm through a locked TC with 1-5/8" Tri-Y headers.
Later with LT 1-3/4" headers and through a non-lockup 8" TC, it rolled 420 SAE.
My cam is same as yours except 108 LSA, also 12:1 CR, but with the stock flattops.

VAformula

iTrader: (8)

Cool, I had hoped to break 400 and my long term goal is 500 when I possibly do another rebuild farther down the road. Have you ever run nitrous on your engine? I know its a high CR so I'm jw.

VAformula

iTrader: (8)

Nvm, I read your sig!

bowtienut

iTrader: (1)

Nitrous and high CR get along just fine.
That lone nitrous run doesn't even show what the 100 shot is doing. That was a spinning 1.42 60'. I've gone 1.43 on motor.

VAformula

iTrader: (8)

Those numbers you make, make me happy

I hope my set up will be near that once I'm done

VAformula

iTrader: (8)

One more question! Should I get a 58mm TB if I'm buying a new one? I mean is there any reason not to for 5 dollars more than the 52mm (or same price)?

bowtienut

iTrader: (1)

I would not buy a new 52. Since you have the intake off, open the holes for a 58.
A 52 only makes sense to me if it's a re-bored stock TB, or if you get a great deal on a used one.
I'm running a 58.

VAformula

iTrader: (8)

Okay, I'll see what I can do, if I find a great deal on a 52 (guy not too far away sells them for cheap) then I'll prolly just go with that. If I buy like a summit or something I'll get a 58 and bore the intake out.

See if I can't find a local machine shop to do it for a decent price instead of sending it to AI or someone like that.

bowtienut

iTrader: (1)

Just a word of caution that may sway your decision whether to go 58mm or a re-bored stocker. Many people have had split BLM issues with aftermarket TB's running high overlap cams, because the IAC passages aren't accomodated by the aftermarket TB's.
I've not had issues, but I think I'm in the minority. Your cam has less overlap than mine, so you may be OK.
FWIW, I'm running a Holley TB (58mm). Holley's have another issue that is easily solved - the mechanical stop needs to be modified to prevent the blades from going past 90 degrees and triggering a TPS error.

TravisMcGill2000

iTrader: (2)

That setup sounds like it gona make some power. My only question is why dome pistons?

VAformula

iTrader: (8)

That's a good question. I bought this block and a transmission for relatively cheap, the guy that had built it had no idea what he was doing and it was pretty obvious. But he put nice parts in the engine. The pistons and rods are all brand new and I figured out how to make the dome pistons fit so I'm not worried about them being there anymore, if I ever do a rebuild I will take them out. Just didn't have the time and money.

VAformula

iTrader: (8)

Thanks for the forewarning! Any aftermarket better than the others?

bowtienut

iTrader: (1)

I really don't think so. It seems anything other than a stock or overbored stock has the potential to cause issues.
However, with that being said, I've had no idle or driveability issues with the BBK 52mm on my stock motor, and now the Holley 58mm on the heads/cam motor.