[Bama]

We know that Chris Straub has made some cars run really good at the track and had others make some big numbers on the dyno. So we know he know what he is doing.

Well i have a friend that runs a Ford 393W
10.5 compression
AFR 185 heads
Victor jr intake
Holley 950HP
1 3/4 headers
car 3100 w/driver
C4 with 8" converter
4.33 gear 28x10.5 slick
was running a hydraulic 239/247 @50 541/565 106
He has the shift light at 6100
car runs really good for what it is 6.70's in the 1/8th will go 6.60's in good air.

Well he decide he wanted to go to a hydraulic roller he called Chris and ordered cam/lifter/springs.

He got the cam and it was 230/234 @50 550/542 107lsa
Is it just me or is that cam not REALLY small for that.

I don't want to doubt Chris, heck i am the one that told my buddy about Chris in the first place after ready about his success on this website. I know Chris talks about the keys are knowing head flow and it's the combination taht matter, but i have heard him say good heads need little cam and "bad" heads need big cams. My friends heads are border line small to begin with which is what made the cam seem even smaller to me.

Am i totally wrong here, i would just hate to see my friend spend all this money and run slower, especially when he is hoping to pick up a tenth or so with the cam swap.

 

[cstraub]

Roller lobe has more area under the curve. When you compare a flat tappet lobe to a hyd and want all things equal the the roller lobes that your buddy has now are equal to a flat tappet cam of 248/252.

The heads are not small for the CID and the rpm range.

Remember Crazy Davey's 2nd cam was smaller than the Lunati he had in it before and the car was faster.

 

[Bama]

like i said didn't want to doubt you Chris just didn't want him mad at me if it ran slower.

So how much more power do you think it make with the roller cam, and what RPM do you think the HP & TQ will peak at

 

[427L88]

Man, there's no amount of speculation by others that can satisfy you on this one. There is only one way he'll know. And I'm sure Chris stakes his reputation on every recommendation.

As the old combat Vet ( thanks to ALL!) saying goes, "BS dont cut it at the moment of truth." Once you start spec'ing out custom cams many of which will have valid A/B comparos done to them, you can't hide from the facts.

 

[67RS502]

move this to the ford section
Chris just does that for ford guys!
If you think thats a short duration, Chris told my ford buddy (yea, I have one)
his 302 will need a 20X duration intake lobe, and this is on a 7500rpm deal.
so it does work, the better the induction the less duration needed.

you need to look at how short the duration is on most of these "custom" cams
its way shorter then most would think, but all that matters is that it works.
These guys know what thyre doing, I've see it more then once, and it will run good
as long as the car is set up right.
240s int. for my pumpgas 420, and still made 640hp
just trust 'em.

 

[71 454]

Regular flat tappet hyd. and hyd roller 2 different animals...:clonk:

 

[87caprice]

Must agree to this

 

[BowtieAaron]

I had a kid come to me with a 347 with victor jr 210cc heads, as a 228/232 or 224/230 I forget in his mustang.
He wanted me to put a cam in it.
His criteria, pull from idle to 6000, no more rpm then that.
Drive good. But sound nasty.

He was looking at 230+ @050 cams,

I called Chris, he said 211/219 on 108. I knew the kid wouldn't do it, so I talked to him about it, he didnt believe me, and insists that bigger cam is what he needs.

Some people just don't have a clue, and others just need to trust the pro's.

Aaron

 

[Roadknee]

That will be plenty of cam for a 6,100 rpm shift point.

I recently had a custom hydraulic roller ground for my 383, older AFR 195's, 6,000 rpm shift point. It's 228/232 @ 0.050". The advertised duration of my existing hydraulic flat tappet and new roller cam is very similar, but the roller is about 5° more at 0.050" and 18° more at 0.200". The cam designer estimates the roller will be good for an additional 40 hp.

 

[cv67]

Its hard thinking smaller sometimes.

Chris will get you the results you want dont worry about that!

once I switch cyl heads may be in the market for one of his cams.
Gonna be hard letting go of the SR though .

 

[BowtieAaron]

I'd like to try one of his cams.

I think I'll call him once I finish gathering all my turbo parts.

Aaron

 

[jeff swisher]

For the size of your buddies current cam and him shifting at 6100 i would say something is wrong with the combo.
I ran 455 olds with 224-234 cam and shifted that big sucker at 6700 for best et.

A 396"bbc with a 230@.050 comp 280H pulls like a jet airplane to 6700rpm where i get valve float due to too little spring pressure.

Those are with ported factory heads.
Same deal with my 350" stuff and the old magnum grinds
270H=224 @050" best shift point for low ET= 6900
280h=230 " "= 7200
292h=244 " "= 7400-7500.

I bet he will be really pleased with the new cam.

 

[BowtieAaron]

For the size of your buddies current cam and him shifting at 6100 i would say something is wrong with the combo.
I ran 455 olds with 224-234 cam and shifted that big sucker at 6700 for best et.

A 396"bbc with a 230@.050 comp 280H pulls like a jet airplane to 6700rpm where i get valve float due to too little spring pressure.

Those are with ported factory heads.
Same deal with my 350" stuff and the old magnum grinds
270H=224 @050" best shift point for low ET= 6900
280h=230 " "= 7200
292h=244 " "= 7400-7500.

I bet he will be really pleased with the new cam.

Then what's wrong with my 355 to make pk power at 6000-6200? I have a 231/239 @ 050 hyd roller.

IMO I think your examples are a little off the wall, and seem eggagerated a little.
Edit: I just have a hard time believing
Big block numbers, and stock headed small blocks revvin past certain points, and making this claimed power.

But then again I'm the one who thinks 500hp is slow also..

Get your stuff on the rollers and see where it really makes this power.

If the combo is good, and you make great power in the mid rang, you don't see to spin it high and it will go faster than the guy who makes power up top and has to spin it to the moon.

Over rpm can slow you down too

Aaron

 

[67RS502]

induction!
if the induction is poor it wont make good power or wanna rev.
If the induction is good it wont take much cam and will make good power and make it high and hold on past peak well.
I agree 500hp is slow nowadays, my 383 only made 490hp and runs high 10s which IS slow, need to fix that

 

[cstraub]

The owner of this car didn't complain about the way it ran. It runs very well. What he wanted was to go roller. I had talked to him for over a year about this project and he pulled the trigger not long ago. What the roller will give him is a broader powerband to use with the car and he should see a nice gain.

 

[jeff swisher]

Then what's wrong with my 355 to make pk power at 6000-6200? I have a 231/239 @ 050 hyd roller.

Well peak power and optimum shift RPM are way different usually you shift 500-700 rpm past peak power. Unless the valvetrain cant go there.

Another key element to higher revs with a given combo is how tight you build the engine.
I have built them with piston to wall of .0015" to .0045" with cast pistons
I will tell you at .0015" the thing will be down 1000 rpm on shift points.
To get that 1000 back you need much more cam to over come the friction.
I have found at .0035-.0045" there was no gain in optimum shift rpm.
These were my 350 builds with cast 345np pistons.

My sbc heads were not stock they were factory heads i ported and worked over..CSA a tad over 2".. none had less than 10.4 compression.

I have no reason to post inflated numbers.
Just the facts from my personal builds.
I used one of the XE268h cams and peak shift rpm on that one was 6500
I was disappointed in that camshaft, The 270H magnum made more power.

Overlap plays an important roll. Don't forget about that

Keep us posted on how the windsor runs with the new setup.

 

[BowtieAaron]

I guess the stock headed combinations I've used we're never optimized.

I only have one good running stock headed motor, and it's a 355 with vortecs on it.

Rest if my stuff was disappointments. I've used xe268,276, 292h, xer273hr114.
The vortec has a 230/236 roller.

Either way, it shows idk what I'm doing, and Chris cam cut A killer cam!

Aaron

 

[67RS502]

part of the problem could be the cam or lack of lift to use the intake port.
not enough duration on the exhaust.
could be the carb, filter, poor ignition, headers or exhaust system too.
see it too often, motor being choke by some kinda restriction.

 

[jeff swisher]

Aaron i would not say you do not know what you are doing..
Just some combo's work and some do not..
I tried over 20 different exhaust combo's on my 78 nova that i built by hand.
Then on to the head porting..been doing it over 25 years.

Most was trial and error..port install on car and run it.
remove inspect and do some more porting..run it..Try different heads.
try different back cut angles..Then carb porting..
Messed up some carbs messed up a couple heads..But you learn that way.
I may have only had the heads on the car for a day before i pulled them and tweaked some more.

Yes it seems that the R&R would get old fast..lot's of gaskets
But i wanted to be faster and quicker without all the aftermarket stuff if i could.
My dad and his buddies raced super gas class and had legit 9 second rides.
All BBC stuff and some ford CJ stuff..
They spent some time optimizing everything.
I have never used the vortecs ..I like my tall tunnelrams and those do not seem like they would fit the heads well ..And the 64cc chamber is a little big for me..Wonder how much you can mill them.
I would angle mill .060" off the old style 64cc heads.
Some of my friends would go .150" Hand grenades we called them.

 

[BowtieAaron]

Jeff, no way was I implying I know more than anyone else, or saying I know what I'm doing. But when it comes to Chris, I'm sure he forgot more than I know!

I got lucky when I did my 355, and it makes power I never it expected to.
376whp with pump gas, 180cc heads, a dual plane, and a 650 through 2.5" exhaust.

But just like everyone, we learn from playing around. Tuning.

Some changes just don't seem correct, like putting a smaller cam in an engine to go faster. But it works!

Aaron