Originally Posted by DUKE
Hey every one I'm new to this . Just put my fist post in the wrong place. will get it sussed. Anyway, I,ve got a 4v, closed chamber clevo thats not working to well. It's got 750DP, weiland accelorator, 224/234@50-536/560lift-112L.C. cam. It's also got 2V evtractors, 2000rpm stall(C10) and 3.55 diff. All this is working against itself. the motor has done just over 20K. Fuel economy is about 13MPG on the HWY. I'm about to change this combo but I'm not quite sure which way to go. I also have a nice set of closed chamber 2v's that flow around 500HP. I'm considering 3 different combos.Idea #1. -2v heads, parker funnelweb manifold,crow hydraulic( Got a new set of hydraulic lifters)242/250@50-570/570lift, bigger stall, maybe 3500 and 3.7 diff. OR Idea #2- 2V's, Torque power high rise dual plane manifold( has anyone used one of these, the look like they would be good)and maybe a slightly smaller cam than above. Or Idea #3- 4V's with tongues and funnelweb manifold. I cant decide which of these combos would be the best. The car is my daily driver. It feels like its only got 200rwhp max though it would have more. I wouldn't mind the fuel consumption if I wasn't getting wopped by hard sneezing nissans. Any advice would greatly apreciated. I'll get some photos of my XC on here soon. Cheers.
My thoughts are as follows:
For an automatic car, you'll want a narrower LSA camshaft with 4V heads. You'll also want to get rid of the Weiand X-celerator and use either a Torker or a dual plane for a street engine. I wouldn't use the Funnelweb on the 4V engine with an automatic in a daily driver. Try to borrow a 650 carburetor and see if your bottom end improves. I suspect that the 750 is a bit much for it. The smaller base plate of the 650 should improve velocity. If you have the space under your bonnet, try a 1" 4-hole spacer with your 750 to see if responsiveness picks up.
The 2V extractors must be a poor fit on 4V exhaust ports. I've never seen anyone able to fit a set of 2V extractors to a 4V without leaking. Are you sure that these are 4V heads?
You could definitely use more stall, but I wouldn't go over about 2800-3200 in a daily driver.
Your camshaft looks like it would be wrong for a set of 2V heads. I'd try to find one that is closer to even up on both intake and exhaust durations/lifts. I would probably look for a 110* LSA camshaft with a set of 2V heads with about 228* effective duration with about .540" lift.
If you stick with the 4Vs, I'd use a camshaft around 234*/246* at 108* LSA at about .550"/.580" lift. You will want about 3200 stall and a 3.7 rear gear. A 3.9 will be more helpful, but won't be as fun as a daily driver.