zeeboost

iTrader: (1)

I have a 370 at the machine shop getting some work done to it before I slap an F-series procharger (thinking F1R) on it. When I bought the engine, it was already built for a procharger and has a 9:1 CR. Specs on the current cam:

Int - 280*, 234* @ .50", .564" lift
Ex - 290*, 240* @ .50", .581" lift
LSA - 113


The machine shop is recommending this type of cam:

Int - 238* @ .50", .595" lift
Ex - 248* @ .50", .585" lift
LSA - 115

Now in my early hotrodding days, I've mismatched cams (bigger is always better, right???) and learned the hard way that everything needs to function as a system. However, since the engine has already been built for a procharger (by a shop supposedly) I figured worst case scenario is that I may lose a few hp without going with the recommended cam, but it shouldn't act like a mismatched cam.

This will be going into a Datsun 240z, so it's not really that big of a deal if I don't squeeze every ounce of horsepower out of this engine. I'm already going to be having enough traction issues as is.

So my question to you guys is how would the driving characteristics differ between the two cams? Would it be worth the extra $400+, or would the extra money be better spent elsewhere? (like a callies crankshaft, because right now it's just a stocker) The shop is waiting on me to figure out the cam situation, so I'd appreciate any help with this. Thanks

Hank Peabody

iTrader: (2)

Figure the current cam you have now, already decently big, with an F1R and about 15psi in a light weight 240 you should be trapping 155mph or so! You're going to be making so much power as it is you probably wouldnt notice any difference!! Gonna be awesome either way! Ive got a measly 216/216 and it works like bananas on the street, your cam is way bigger. Your tires =

Inspector12

iTrader: (29)

Well I don't know HOM much of a difference its going to make, but that extra exhaust durration it deffinately not a bad thing and will help you a lot up top. Now is is worth the extra $400??? You could try what you have and change it in the car and you will know for sure what its worth, but that is just a suggestion GL!

Fb0dy0nly

iTrader: (10)

First off, I HATE WHEN I SEE THREADS IN HERE THAT SAY, "HELP ME CHOOSE MY CAMS" but we don't own mustangs so our engine only has ONE, I repeat, ONE, singular CAM. Sorry....

But inspector is right, Get a little more up top for sure with the new cam and it may not end up being a $400 swap as you can always sell the old cam for a couple hundred and get at least half your money back and now that power is only costing you +/-$200. If you can do that, I'd say go for it OR if you want TRUE expert advice, hit up Patrick G or Predator Z for the best Cam info on these things. Good luck with the build.

zeeboost

iTrader: (1)

Yes I know there's only one cam in my engine...I guess I was just thinking in the plural sense because I'm deciding between two cams. But anyways I appreciate the input, however I'd like to gather more opinions on the setup. Hopefully Patrick or Predator will chime in so I don't have to bug them through PMs

zeeboost

iTrader: (1)

Anyone have more input?

grpaic

what kind of power are you looking to make?

zeeboost

iTrader: (1)

Aiming around 800-900rwhp

STAR

iTrader: (1)

I would bump the compression to 9:5:1 and go with the bigger cam. A Datsun 240 is lightweight and you wont need any more power down low, I'm guessing traction is going to be a problem anyways

zeeboost

iTrader: (1)

Are you suggesting to bump the CR to match the bigger cam?

Honestly I'd rather not screw with the CR since I already have the pistons/heads ready to go.

crashly

how much piston to valve clearance you got ?
why change the cam, if the pistons have been ordered for that cam ??

grpaic

Not much of a change for $450 bucks, With the F,The duration is very good , i would bring the lift to around 600-610 and definitely get the LSA 114, 113 is prefered for a kick in the pants, let that sucker breath

zeeboost

iTrader: (1)

I do not know that measurement. I bought the engine already built for boost, but wanted everything checked out before I ran it. The machine shop suggested the cam change...otherwise I was just planning on running what it came with. It was originally designed for a 600rwhp build (guessing D1SC) so I was thinking the cam may be a little mismatched for my increased power expectations. However, it's not like the profile is completely mismatched and I'm running an all out n/a cam. It's still a blower cam...just don't know if it will hinder me enough to justify dropping $400+ to upgrade.

I'm a little confused, you suggest that it wouldn't be much of a change for the $$$ (which looking at the numbers I can see that, but that may not accurately represent the real driving conditions), but then the rest seems like you're favoring the notion that I upgrade the cam.

When you were talking about a kick in the pants, are you suggesting that it will be lacking in more low end power, but then hit harder once I get in the powerband? If so, that seems like more of the cam I'm looking for. I'd like to shift my powerband to around the 2500-6500k range...wheel spin will already be a PITA with this car.

I appreciate the replies so far, but I'm hoping to get more insight on this. Thanks

grpaic

those numbers do represent real driving conditions, if you are going to slap an F1 on the motor I am suggesting to get your lift to around 610 and your LSA at 113 for better low end power.