N20Dave

I'm looking to see what converter's you guys are using with big cams, preferably big solid rollers. THanks.

Stephen 87 IROC

Define a big roller? To me a big roller in a SBC is anything over .630 lift.

BigRick

A2 Glide, 1.76. 4.30 gears, 29.5 tire. 396 LT1 solid roller. I spin 8K RPM. Cam is a 275/284 @ .050 .736/718" w/ 1.6's. Big enough?? Converter is a BTE 5000 stall on the trans brake.

N20Dave

Thanks guys. Big to me is anything over 250 degrees @.050 with over .600 lift. Anyone else. I'm trying to get a basic feel for how big I can go with the cam and converter and still be able to get to a couple of car shows each year as well as race. Bear in mind I'll drive just about anything on the street.

Jason Short

Well, a 250ish solid roller with a stroker is pretty small IMO. I had a 247/250 .658/.659 112 in my 396, and it idled like a HOT cam in a stock motor. VERY tame.

To me, a 260+ duration cam is where they start to "act" big.

Can help you on the converter tho.....M6 guy here

Hope things are going well Dave
Jason

rskrause

Jason: too much! What's small to you is big to me. But your car did idle great with that cam. Maybe sometime I will do a high-rev/solid roller thing. Then again, I'm addicted to boost.

Anyway, I don't have anything of value to add here, so I'll shut up now.

Rich Krause

Stephen 87 IROC

OK, just to compare specs, here's my BBC.

Flat tappet solid cam. I don't have the head work for a really big roller yet but this cam is as big as I can go without going to a roller.

.638 lift I/E
270/280 @ .050 I/E
110 LSA

I use an 8" JW race converter that stalls on the transbrake at 5700 rpm. 4.56 gear through a TH400 and 29" tires.

What's considered a big cam depends a lot on the engine. A cam that's mild in a 406 would be big in a 302 or 283. Big engines can tame more aggressive cams. My engine could really use a .7xx roller cam with something in the 280/290 @ .050 duration. Maybe when I build a 540.

BigRick

I love it when I hear my cam is bigger then a big block cam But you better have heads that flow or a big cam will just hurt you.

Stephen 87 IROC

Mild BBC heads flow as much as heavily ported SBC so there is a big advantage and they already have larger valves to match.

Don't forget I have pistons the size of coffee cans and a much longer stroke than a SBC so I have some killer torque out of this engine. Although the engine could probably go to 8000 rpm, I only shift at 6700.

N20Dave

That's some good info. Jason, things are fine thanks, how bout you? As far as the cam goes, I'm doing a 383. My heads are full on race pieces but they flow pretty good. In the 270's on intake and almost 220 on exhaust. It's gonna get a 200-300 shot of juice as well. I want 500 to 525 flywheel minimum from the motor and I'm not sure I can get that with a hydraulic roller. It's a considerable expense goind solid roller so I wanna make sure it's worth it.

BigRick

You're gonna need a lot more head if you're planning on putting a high lift cam in there. My heads are choking out with my cam. My heads are AFR 220's that flow 335/240. I have a lot of money tied up in these heads trying to get them to flow. 270 is your basic LT1 stage 2 job. I wouldnt try and over cam it. Jus tput a nice cam in and juice it like you said.

N20Dave

I understand what you mean about the heads. My heads are not LT1 castings. They are Trick Flow castings that have a little more work to be done yet but the low lift figures are nice. I think I can get them in the high 280's low 290's before it's all done. The cam I want to run is a solid roller with the specs of 258/268 @.050 .615/.617 on a 114 lsa with 35 degrees of overlap. The motor has a Callies crank, Oliver forged rods and Diamond nitrous pistons. It's 11.5-1 comp. I have a th400. I had Hooker lt's but Am thinking of going with the hedman 1 7/8. It's my feeling that a solid roller with quicker ramp rates will ba able to take better advantage of the very good low lift numbers even if I can't get as much high rpm power as the cam will allow due to some cylinder head restriciton at this point. I could be way off base with this. I was also thinking of a cam that has about 10 degrees less duration with lift figures in the high .500's. These heads hit the peak flow on the intake at about .575 lift but they didn't fall off when taken to .600 and .650, they just leveled off. Someone please give me some guidance if it appears that I've had a stupid attack.

BigRick

Both of those headers have been tested and they're is no difference in power. The Hookers actually made better low numbers on a 409 Ci Stroker. The design in the runners is better on the Hookers. I have the Hedmans on mine. But for the price difference I wouldn't spend it, if you want something bigger get something custom built, like some Lemons headers. Also the plugs are a lot harder on the Hedmans vs the Hookers.

N20Dave

Thanks for the advice on the headers. I was thinking that 1 7/8 might be a little big for what I have but that it might help on the spray. I think I'll just stick with the hookers.