SUM-6901 Cam

[aspen77rt]

Yup I see it now, the valve can be open to its max quicker thus for the same durantion let more fuel in, I see the advantages of of a larger diameter lifter, so what off the shelf cam would work good in my combo, there is a list to choose from above I am like a :icon_eyes:

Not really to it's max.

Two cams with similar lobe designs have the same duration at 0.050 lift, maximum torque and horsepower will be almost identical. However, the cam with the quicker opening will have a smoother idle, better off-idle response, superior low speed drivability and a broader power curve.

 

[aspen77rt]

That's one of the biggest reasons a roller cam will outperform a flat tappet (aside from the friction reduction). The ramps can be really steep and the valve can stay open farther for longer. I'd love to go roller but, well, you know,,,,,,,,,,,,,$$$$$$$$$$$$$$$$.

Bingo

 

[aspen77rt]

Cam selection is a science that I never mastered! The really best way is to talk to the manufacturer and get their recommendations.
If you stray too far from stock specs, then you also run into geometry problems using stock valvetrain parts.

This be gooood advice

 

[Bruceynz]

ok so the sum-6900/1 is good bang for buck but not best performance, I now see why they are called a Chevy grind, they are a chevy grind on a chevy cam stick to fit a mopar, not a mopar cam designed for larger lifter diameter ok. There must be someone who has built up the combo I have and found a good mopar bump stick grind. I don't live in mopar country so I can't send stuff back or spend hours on tech lines, I will out line my setup and what I would like.

Want 5000rpm ish maybe 5500rpm, stock converter on A998 wide ratio trans - I think my XXX714 heads will be maxed out at 5000rpm for air flow as stock, anyone elses thoughts?

Holley 600cfm vac sec electric choke
XXX714 heads (same as XXX302 just later model) I am going to get the heads pocket ported and port matched.
Performer Intake
After market dizzy and module with adjustable vac advance
The summit 6900 cam but I am thinking I can just order another cam and use all the other stuff I have, double roller timing chain, lifters, valve springs etc
I have a 3.21:1 8.25" open diff to go in the car as well.

Thanks
Bruce

 

[Bruceynz]

They say you can't beat mother mopar is this what I should be looking at which one hmmmmmm, what will work with stock converter

[h=2]Mopar Performance#312-P4452757AE[/h]Purple Shaft Hydraulic Camshaft & Lifter KitChrysler 273, 318, 340, 360 Advertised Duration: 248°/256° Centerline: 110° Lift: .410"/.425" RPM Range: 1000 to 5000

or

[h=2]Mopar Performance#312-P4452759AE[/h]Purple Shaft Hydraulic Camshaft & Lifter KitChrysler 273, 318, 340, 360
Advertised Duration: 260°/268°
Centerline: 110°
Lift: .430"/.450"
RPM Range: 1200 to 5200

 

[aspen77rt]

Want 5000rpm ish maybe 5500rpm, stock converter on A998 wide ratio trans - I think my XXX714 heads will be maxed out at 5000rpm for air flow as stock, anyone elses thoughts?

I wouldn't even bother with wanting 5000-5500 rpm's. Build it how your going to realistically drive/use it.

This is the Mirada's usage as I noted on the cam sheet for the cam grinder.

This will be a occasional cruiser. 60 mph/2.94 gear/27" Tire/1.00 trans final gear = Approximatley a 2200 rpm cruise. Not factoring in the lock-up which will lower the cruise rpm. Use 70% highway @ 55mph+/30% City stop and go. Will not see the track other than screwing around. Would like to maintain at least 15" of Vac with decent idle quality, but indulge yourself.

The cam specs
Intake
269 adv, 220 (.050"), 138 (.200"), Lobe Lift .316" (.506" w/1.6")

Exhaust
273 adv, 224 (.050"), 141 (.200"), Lobe Lift .316" (.506" w/1.6")

On a 112 Lobe Separation Angle, Installed at 108 Intake Centerline

 

[aspen77rt]

They say you can't beat mother mopar is this what I should be looking at which one hmmmmmm, what will work with stock converter

[h=2]Mopar Performance#312-P4452757AE[/h]Purple Shaft Hydraulic Camshaft & Lifter KitChrysler 273, 318, 340, 360 Advertised Duration: 248°/256° Centerline: 110° Lift: .410"/.425" RPM Range: 1000 to 5000

or

[h=2]Mopar Performance#312-P4452759AE[/h]Purple Shaft Hydraulic Camshaft & Lifter KitChrysler 273, 318, 340, 360
Advertised Duration: 260°/268°
Centerline: 110°
Lift: .430"/.450"
RPM Range: 1200 to 5200

Most major cam companies have online cam recommendation sheets and they will email you back with a recommended cam. I know Comp and Lunati definitely do that.

Shop around, Mopars PS grinds are decades old.
http://www.hughesengines.com/Index/...Y2sgIkxBIg==&level1=Q2Ftc2hhZnQ=&partid=30238

http://www.hughesengines.com/Index/...Y2sgIkxBIg==&level1=Q2Ftc2hhZnQ=&partid=30237

 

[Bruceynz]

Maybe my sum-6900 cam is not optional I should just stick with it as it will be a big step up over stock, I just have an opportunity where I could get another cam.

 

[brotherGood]

IMO, and don't take this wrongly..but you're over thinking it. Sure, you can drop another 70 bucks on the 6901, or something else..but the cam you have now will work just fine. My magnum heads had a valve job done and that was it. But no sense spending so much on the optimal top end/cam, when your pistons are so deep in the bore. I didn't really consider it when building my 318, but my 360 will be done for maximum efficiency.

With those 3.21s, you'll take off faster than I will..but I hope you don't plan on doing highway driving..you'll have pretty high revs your whole trip.

 

[Bruceynz]

Hi,

Yeah I think you are right, I got to get out of my head its not a race car and I don't need to squeeze every HP out of it. I wanted a 2.94 8.25" but ended up with a 3.21 when we go away on vacation we always take the wife's people mover with the kids so my mopar sees very little highway work.

Thanks
Bruce

 

[jasperjacko]

Forget the cam, forget the 3.21, and put a turbo on it!!! YEAH!!

 

[brotherGood]

Forget the cam, forget the 3.21, and put a turbo on it!!! YEAH!!

Get better mileage that way too

 

[Monkeyed]

I'd love to go roller but, well, you know,,,,,,,,,,,,,$$$$$$$$$$$$$$$$.

sorry for my ignorance, but I thought these cars had stock roller cams? Was that just certain years, or did I just read something wrong,..

 

[kkritsilas]

Later years of the 5th Avenues are roller cams. None of the J Bodies are, to my knowledge; they were out of production before the roller lifter engines appeared.

Kostas

 

[Monkeyed]

Later years of the 5th Avenues are roller cams. None of the J Bodies are, to my knowledge; they were out of production before the roller lifter engines appeared.

Kostas

ok thanks, that's what I thought, just wanted to make sure. I talked to my machinist the other day about maybe bringing my 318 up to him to "freshen up" a bit. He's an older guy, and into the really old stuff, but he thinks he might have a thermoquad laying around somewhere.

I'm thinking about a cam and maybe .030 over (if it needs it), probably want it as stock as possible to save $$$$s. lowest idle I can get, smooth, driveable, 4,000 rpm max, lots of torque.. want a bad@ss cruiser

This thread rocks! :thumbsup: