90 7.4L upgrade?
 

I would like to do some mild upgrades to this engine. Was thinking about putting a mild modified cam and different lifters/rockers..... I take it that the current configuration is hydralic lifters? and non roller rockers? Anyone have some ideas for me for a cam and setup to get a couple more ponies out of her? I'm new at the engine stuff, but i want to get my hands dirty in it. thanks

Re: 90 7.4L upgrade?
 

You can put a cam in the range of about .550 lift and 230-240 at .050 in duration.You could mill the heads to bring up the compression.Head work [porting] is a decent power maker too.

Re: 90 7.4L upgrade?
 

what is stock lift and duration, doesn your second and third set of numbers refer to the lifters, or still the cam, any manufactures for the cam or lifers/rockers??

Re: 90 7.4L upgrade?
 

those would be duration numbers as measured at .050 and refer to the cam. that is how most cams are listed.

Have you ever installed a cam???

If you get a larger cam, depending on size, you may need new exhaust to prevent reversion.

Re: 90 7.4L upgrade?
 

BTW, with the upgade you might see a 50 hp gain which equals 3mph on the top end.

Re: 90 7.4L upgrade?
 

well, i'm only looking to spend around a thousand bucks, don't want such a wild cam that i have to change a bunch of other stuff, just looking to do the cam and maybe the lifters and rockers. No i haven't done it before, prolly won't do it either, will have my mechanic do it. Just askin some questions here. Where or who would i get the cam and parts from, do they sell the stuff as package deals at all??

Re: 90 7.4L upgrade?
 

Call Crane Cams or Competition cams and tell them what you want. I'd keep it 230 or less duration. You will need new springs unless your motor is a magnum then you could probably get 550 lift range as is.You'll need to check clearances to piston from valve and for spring bind. You could go to 1.8 ratio rockers too and get more lift from the cam without as much tradeoff in torque you'll have from a MUCH larger cam. Your stock ratio is 1.7. Go ahead and do it yourself,but get a good book"How to hotrod BBC" and read up over the summer then do it in the winter,,,,'cause you got some learnin' to do and summer is not the time for that. Maybe disassemble yourself and pay your Mech to show you how to assemble. But start reading before you get dirty :)

Re: 90 7.4L upgrade?
 

just got off the phone with mechanic, basically he highly advised me not too mess with the cam. He said as soon as i put a different cam in the idle will go up to be reliable, then i good take out the drive from engaging at that higher rpm's. Keep in mind i'm not looking for a huge lift, just a little something extra. He also said i would prolly not be able to get a skier out of the hole either with a cam mod. Any other opinions??

Re: 90 7.4L upgrade?
 

i have a bravo one drive, btw

Re: 90 7.4L upgrade?
 

The main restriction in the 7.4 are the peanut port heads. Their flow is limited at high rpm. The stock cam is conservative and is probably tuned to also to be limiting at high rpm. You'll need a cam + headwork to see any noticeable difference.
Gary