Mustang Hat'r 2

iTrader: (24)

When does a cam become to big and WTF does that mean?

Can see things moving the Power band up but what would make it loose power.

Motor is a 418 with LQ9 heads that flow 360. Want to shift at 6800 and its a M6 idle rough.

Had a tr224/224 112 in 346, tam to me felt like nothing
Had a 245ish 255ish on 112 XRE lobe (the faster ramp one)in a 383, was nice cam. The drivabilty was fine for the 383 so I'm not scared of a bigger stick

In a 418 would like a 260/265 be to much on maybe a 110-112 LSA? The reasoning for my first question. A 418 should be pretty torque down low but would like a power band of maybe 4k to 6800.

thedak

iTrader: (1)

That is too big.

Mustang Hat'r 2

iTrader: (24)

My 383 was a little bigger and it made 450/450 hp/tq. Thats what they guy that bought it from me said. But it had shity patriot heads and a78mm fast. Better head intake would have made over 500.

DrkPhx

iTrader: (15)

Did EPS spec that cam?

ringram

Looks like a comp LSR lobe/grind to me DrkPhx

Also general rule (according to Vizard) is to take a cam you like and add/subtract the sqaure root of the difference in cubes between the engine with the cam you like and the one you want the cam for to determine rougly the duration you want.

For example 346 with a 224/224 cam stepping up to a 408 is 62 cubes difference, sqrt is 7.8 so say 8* therefore a 232/232 would perform about the same.

That suggests to make the cam similar to the 383 with the 245 he would need about 4-5* extra duration so say 249/260

So the 260 he is suggesting is fairly big step up.

thedak

iTrader: (1)

Yes it is a LSR.

itsback08

iTrader: (12)

you useing a SR?

Mustang Hat'r 2

iTrader: (24)

My lack of knoledge is making the question some what hard to ask.

Cam I want the car to rock when it idles, **** stealth I want people to know its got a big stick in it.

LSA effects the idle and power band, 110 is more peaky and higher up than a 114?

When is duration to much now I know a 250/250 will make more than a 224/224. What happens when I go huge, lets exaggerate it. What would a 280/280 do in a 418?

Like the main question when is a cam to big and what exactly does that mean. Im not a wizard with this **** so try to make a normal person kind of understand. Here it all the time that cam is to big why?

itsback08

iTrader: (12)

well i just had a 408 in my trans am.. cam was a 264-272 with lsa being 110. with out of the box afr's running 10.2's all motor threw an auto. that was a solid roller cam... not sure when a cam is TO BIG as i am not an engine builder...

Mustang Hat'r 2

iTrader: (24)

Nice thats the biggest Ive seen., how does it idle and what is the power band like?

Wonder what the limit is to hydro and when you need to go solid roller

itsback08

iTrader: (12)

had it tuned at the track. idle was AWESOME!! yea not sure on hydro tho.. with my lil 346 i had a 242-242. also on a 110lsa that ran damn good with low compression.

but anyways good luck. sorry i cant really help ya. just tell you what i had and what worked for me..

Bring the Noise

With L92/LS3 heads if the cam is to large then you will start to see the affects of reversion. With the cathedral port head usually having a slightly higher velocity to the air flow reversion is less likely (but can happen if you just go with a stupidly large cam). Note: This is mainly for the intake side.

LSA - Tighter/Smaller LSA will move the torque and hp peaks lower in the rpm range.
The tighter the LSA the more scavenging the engine will do in the lower rpms.

And lobe size is not the only thing you should base your cam on.
Remember ramp rate and max lift play just as important a role as lobe size and separation.

If the cam is not spec'd correctly for the engine and drive-line setup. Then you can run into Bogging off the line (where the engine does not rev fast enough in the lower rpm's and basically slows the car down).

Basically you can have a cam that makes great power on an engine or vehicle dyno. But due to the lobe size, ramp rate, lsa, etc it just doesn't rev fast enough through the rpm range. This will make the car slower then running a slightly smaller cam or maybe a lighter LSA with the same cam design.

Mustang Hat'r 2

iTrader: (24)

So what would you recommend? I wont spin it more than 6800, its a M6 with 3.90 gears and should weigh about 3500 with me in it. Power can start as low as idle but want it to be really strong from 4k to 6800.
How about a 260/270 on a 110LSA with a 650 lift and the fast ramping lobes. Would that work or should I adjust it? Advance 4 degrees?

XtraCajunSS

iTrader: (2)

I really wouldn't go over anything in the 250ish 260ish range with a stock type intake. I've got a couple of killer custom grinds that would give you what you are looking for. With the power band you are asking for, and the personality you want, compression will be your friend. Shoot me a PM or give us a call at the shop, I'd be happy to go over the advantages and disadvantages of such a setup. We've just finished up a couple of crazy setups like this.

Thanks,
Shane

Mustang Hat'r 2

iTrader: (24)

Okay Ill have to give you guys a call when ready. Doing all the research before any of the build is started.

Fbodyjunkie06

iTrader: (10)

I'd go with a big LSK or LSR grind. I'd consider this a very streetable small grind for a 418 cubic inch engine .231/.239 .617"/.624" 113 LSA and should scrape 6800-6900 rpm. This here would be a step up to a more racier grind with a .243/.251 .624"/.624" on a 114 LSA and make its power at 7000-7200 rpm. From what you said this next cam is the size cam you are considering. This is what I'd consider a very big cam a 251./259. .624"/.624" 114 LSA. That should bring the rpm range well into the 7200 rpm range which is outside the rpm range you said you wanted. I think that the second cam I mentioned would work very well for what you want. You could even bump it up to a .247/.255 .624"/.624" 114 LSA but that bumping duration also means bringing the rpm's up more. These are straight out of comps catalog I'm not a cam genius by any means but they were labeled strictly for 400+ c.i. engines with cathedral port heads.

the jester 812

iTrader: (5)

has anyone noticed that some people are giving out advertised duration, like the guy that said he ran a 264/272 cam, and some people are stating duration at .050. because a advertised 264/272 is really like a 212/216 at .050. so i understand why the guy might be confused, but theres a few threads about this stuff that might help
https://ls1tech.com/forums/advanced-...-duration.html

the jester 812

iTrader: (5)

if your talking duration at .050 i'd that thats hella big. but if your talking advertised duration then it might be a little small. you can also go and look on the dyno section and theres a thread with nothing but 400+ ci guys and their builds and dyno's it could give you a direction to go in. thats actually what i did.

KCFormula

iTrader: (4)

People had different theories about LS1 heads back in '99/'00 too. In the end everyone wants to run a bigger cam because they usually create more peak hp. Valve timing is key, and also an independent variable vs size.
Now this is a big cam....
LSM LS N/A Cam Std 2.165/55mm
Int. Lift .748 Exh. Lift .748
Int. Dur Exh. Dur
@.050 278 @.050 292 with 1.70 Rocker Arm Ratio
Lobe Sep 113.0

FMS_FTW

Think about.. in that post he said it was a solid roller 408. Why would he have a cam that was 212/216 at .050 in a solid roller 408?