89formula350b2l

iTrader: (11)

I thought I had selected the cam upgrade for my 383 HSR...well after looking at some cams on Thunder Racing, I saw the 292xfi
292XFI
Hyd. 2200 to 6200 07-468-8 292XFI
Dur @ .05 242 248 .584 .579
Lobe Seperation 113


Here is specs for xr288
Gross Valve Lift 0.52 0.54
Duration At 0.05 236 242 Lobe Lift 0.347 0.36
Lobe Separation 110


Car is only weekend warrior with mainly strip use but still want to have SOME streetability
The most stall I would put on this car will most likely be 3500-3700

89formula350b2l

iTrader: (11)

ttt

86LG4Bird

iTrader: (1)

Without hesitation, The XR288 is the better choice.
Want to go even quicker? Cut down the duration numbers even more and narrow the LSA to ~106.

GofasterFirebird

iTrader: (3)

I really like a single pattern for your combination. My 240 240 works great. Went 11.8 @ 118mph with the same Edelbrock TES headers. I did a TON of research before having Comp grind it custom. They only change about $300 for a custom cam as well. Not sure what TR is charging, probably more.

As you know, there is more to cams then .050 duration. Look at the open and closing timings too. PM me if you want my full specs.

If you are running a 730 ecm, I think tuning will be more difficult with a lower numerically lsa. The higher numerical value the idle KPa on the MAP might make things a little more time consuming.

That being said, I'd personally go 240 degrees staying with a 112LSA.

86LG4Bird

iTrader: (1)

Gofaster, I agree your suggestion of a 240 dur w/112 LSA is also a better choice than the 292 XFI.
My take on the XFI cams: Yet another marketing ploy to sell people big duration numbers for boasting purposes while still saving them from total disppointment, by spreading the LSA, sacrificing power across the rpm band just so the engine will not fall on its face at low rpm. Very few people will ever realize benefits from those cams because its difficult to control the valvetrain at high rpm with those ramps. I'd go solid roller before tackling the high spring pressure/heavy hydraulic lifter headache.

I suggested the tighter LSA (106 is acutally conservative for the R/S ration in his stroker) since it looks like he's pretty serious and spending money and time to go faster, therefore should be willing to spend some effort tuning it. In fact, tightening the LSA to 106 and reducing duration (mostly on exhaust since his AFR's probably have a good E/I flow ratio) to arrive at the same overlap as a ~240/240/112 grind would result in a faster setup.

Damon

Happiness is often a smaller cam than you think you need. If you're going to do one of them, I'd do the smaller one.

Tight LSA is nice for power but don't think that tuning it is going to be easy. Especially down at near-idle speeds. You will probably find that you can't rely on your O2 to run things very well down in the low RPMs with a high overlap (tight LSA) cam. 110* LSA is probably a good compromise for street/strip application like you are planning.

Guest

Comp must be late to the party then, because a whole lot of those LSx cams are ground on 111+ LSA's with tons of duration and lift.

The XFI268 has less intake duration than the famed Lingenfelter/Accel 219. It just has a lot more lift.

86LG4Bird

iTrader: (1)

We're not talking LSx motors here. Those are a whole different game.....better head flow requiring less valve overlap, plus their PTVC issues that won't tolerate tight LSA's.

89formula350b2l

iTrader: (11)

I have entertained the idea of doing a single pattern cam, but I cant find any that are off the shelf. I do want to stay for on the shelf cams for simplicity sake.
Are there any single pattern off the shelf camshafts?

Guest

The OP already has better heads and many of the really fast LSx cars are so far from stock your point about PTVC is moot.

I think you're missing the fact computer controlled cars dont like 106 LSA's, or that XFI cams arent big duration cams but rather high lift cams with a little wider LSA than most that have been out there to this point in time. I went from a SLP cam (with near same duration but less lift and slightly less LSA) to a XFI and I've got better idle, more power everywhere, and better fuel mileage. And the car is faster. Zero downside.