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cam decision
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Posted by: michael12203

Hey, will a carb cam that has been put into a crate motor that we changed to efi hurt the power? It is a roller block, so i was wondering if i would having a roller cam with roller rockers help. The cam that is in my motor now is compcam it has a .512 lift flat tappet. Please let me know

Posted by: StoneFox

you should have gone with the roller cam in the first place, because they make more power. It depends on the fireing order on the cam. If its 351w cam it will work fine with the EFI, If its an old 302 fireing order cam you can still make it work but you will have to swap some wires around on the main harness or it will idle funny. Its also going to have to be a Mass Air EFI. Speed Density will run terrible with that cam.

Posted by: Grape Ape

I agree with what SF said, except the flat tappet not making as much power as the roller. Flat tappet cams can make oodles of power just like hydraulic rollers. Often they're more aggressive from the looks of their specs.

The cam you have should work well, provided it has the "W" firing order. If it doesn't, plan to swap it because of what SF explained. If you do, go with Mass Air to get a much larger selection to choose from.

Posted by: michael12203

well we had the motor built by and engine shop in az, and he put that type of cam in it and the motor went in a 95 so we went back fuel injected, it just dont feel like it is that strong for it to be rated at 350 hp and they said that might ba a prob, i just did not know what yall thought.

Posted by: Grape Ape

What heads are on it? And what injectors, etc. are used? Mass Air???

Posted by: michael12203

i have new gt40 aluminum turbo swirl heads, i have 24lb injectors 70mmtb 73mm c&l maf professional products intake, 155lph fuel pump. The fp is at 41.

Posted by: Grape Ape

That should net about 265rwhp for most Mustangs when running properly. I had that setup once an my car made about 250. That was an automatic. My cam was different, but has .510 lift on both sides and had a small duration. I would think yours is making about that much power.

Posted by: michael12203

when we had it dynoed on a mustang dyno it put down 235 but the timing was not right on it, what was yours dynoed on? Would it be worth putting a roller cam and rocker in?

Posted by: Grape Ape

I don't recall having that setup dyno'd, but I've seen many like it on the dyno, and the numbers are always n that area with proper tuning. I figured my estimate based on vehicle weight and 1/4 mile ET's and mph of the time. Those I've seen dyno'd were all on a DynoJet 248c chassis dyno.

Posted by: michael12203

what times do you think i should be turining w a 5spd and if i hook good

Posted by: Grape Ape

Couldn't tellya. Depends on far too many factors. If I were driving, and it was a track I'm very familiar with, and the car is running as it should and has traction and is in the proper temperature range ontrack and in the engine, and I don't miss any gears, maybe 12.80's + or - a couple tenths, but that's just my guess with those factors in mind.

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