[shortdog]

combo now updated and pointed towards its completion, shy of a cam. I was thinking something 1 or 2 steps above a early model muscle car cam maybe? any suggestions? thanks.

.060 over 383 stroker (388)
cast crank
forged 5.7 rods
forged flat top kb (11-1 w/64cc)
trick flow r 215 heads 1.530 d/s good to .700 2.08/1.60
vic jr intake
1.5 roller rockers
built 700r4 (no converter yet)
3:73 posi

all in a 86 monte ss that will be used mostly as a weekend street warrior..

 

[xntrik]

About 226* actual duration @ .050, 106 LSA

all the lift you can get,

whatever cam type you choose,
prefer roller,
beehive springs

should peak give you pretty flat from 4000-5000
and pretty flat from 5100-5600.

You really need an AirGap type dual plane w/ 750 air-valve/vac-secondary carb.

If you go Victor Jr., use 230* duration, but, I think the airgap will out perform it in that heavy car with AT.

 

[BigBlockBanjo]

Hey Xntrik,
I'm assuming that 226 @ .050 is very warm in a 383?
Like I said in another post...I'm a Mopar guy.....
But I put a 224 @ .050 in my Slant Six! It has .480 lift, 44*overlap, and 110* lobe seperation. :evil: Is there that much difference in chevy motors, cam-wise?
School me on this!! That just seems like a small cam for what he's looking for.....
BBBanjo

 

[baddbob]

Yeah, I'd be thinkin a cam with 235-240 @ .050 would match the rest of the parts list good.

 

[xntrik]

Yeah, I'd be thinkin a cam with 235-240 @ .050 would match the rest of the parts list good.

He said

QUOTE all in a 86 monte ss that will be used mostly as a weekend street warrior.. QUOTE


Look at the LSA. It will put his power bands right up as high as his short rod engine can stand it. 106 is 8 degrees more overlap than 110.

Duration determines where the power peaks at. LSA determines the fatness of the torque curve.

LSA is a figure determined by the intake valve size per cylinder volume, and of course it determines overlap. The larger a cylinder is, the more overlap is necessary to fill the cylinder in the alotted time through that tiny valve. milliseconds.

Let me qualify that= the same size valve in a 302 will fill the cylinder easier than the same size valve in a 383.

His running weight will be more than 3800+ pounds so with a 230+ cam he will need 3000+ stall.

I was tryiing to keep his torque curve fat and not make him scream his engine 6000 to get down the street.......uh,,,,, track.

With the 226 x 106 cam he should have a tire burner, and strong pull from 2500 up.... a real charge from 3500 to 5600, and do it with a 2400 stall.

He should be able to run this 11/1 engine on pump gas.
If you feel you want to spin it 6000 and beyond, go bigger, but you should have longer rods.
JMO :thumbup:

added= also the single plane intake will make life below 1500 rpm miserable with a 236+ cam.

 

[shortdog]

xntrik, several on another site have suggested a lunati cam #401a6lun : 243/251 .518/.530 110/104 what could I expect from that cam, good and bad? they advised to run a 2500 stall and lock up con. with the 700r4.

motor will be closer to 10.5:1 according to my engine builder.

 

[killerformula]

Actually I think those monte's (g-bodies in general) are quite abit lighter than previously advertised. 3200 pounds would be my guess, in fact, the cutlass is one of the lightest platforms out there for a GM if I remember correctly. You have a good place to start. Here's a link for your car's weight, scroll down to the bottom. This site just happened to have it.http://www.quickperformance.com/Technical%20Info/sus_measure.htm

Depending on the gasoline available in your area, you might want to be careful about the compression even with aluminum heads. If you're experienced with timing curves and carb jetting, then do what you feel is best. If not, I would suggest 10.5 or less even with the aluminum. Either that or plan on running a better grade of gas. Pinging and spark knock is less likely to occur with steeper gearing and a lighter platform as well, so bear that in mind. In the end, however, you may end up chosing a ratio that your cam dictates.

I really do think you have a lot of head for your combo, but I also see you have the rest of the motor set up to handle some punishment (your forged components). Forgive me if you've already stated this, but you are planning on a full balance, correct?

As for your cam, I assume you'll want something closely matching your heads, which assumes a power band of up to at least 6500 R's. Hydro rollers are nice, but they're somewhat rev limited due to the mass they add to the valve train, so make sure you talk to a cam expert about that issue. You might send a PM to coldknock, he has a guy who he sends heads to who custom grinds a cam for the RPM band and matches the grind to the flow points on the head.

K

 

[Rick WI]

The closest combination we did to that motor we used a solid roller, that was an actual 11:1 motor. Otherwise the combination overall is the same. Those are great heads and with a flat tappet and that compression you certainly want to be in the 240 duration range. The split on the duration is in the ballpark, maybe a tad long, but that Lunati cam needs way more lift. Get it ground with at least .550 to .580 on the intake and I'd run slightly less on the exhaust.

No way in gods green earth would that motor run on pump gas with a mid 220 duration camshaft.

 

[wildman926]

Shortdog,

You will like the 401A6Lun for your setup.

Advertised Duration IN/EX: 276/284
Duration @.050 IN/EX: 243/251
Gross Valve Lift IN/EX: .518"/.530"
Lobe Sep Angle / Intake Ctr Line: 110/104
Valve Lash IN/EX: .026"/.026"
RPM Range: 2500-6800

I have this same one in my 355 sbc in my 85 GMC shortbed, and it will pull up the way to 6800 ( I only let it do that once). It has plenty of torque down low due to the mild seat timing/fast valve action, and it works my power brakes just fine.

 

[xntrik]

Actually I think those monte's (g-bodies in general) are quite abit lighter than previously advertised. 3200 pounds would be my guess, in fact, the cutlass is one of the lightest platforms out there for a GM if I remember correctly. You have a good place to start. Here's a link for your car's weight, scroll down to the bottom. This site just happened to have it.http://www.quickperformance.com/Technical%20Info/sus_measure.htm

K

I was referring to running weight.....AC, ps, pb, full fuel and one standard sized 170 lb. driver in the seat.

Thanks for the good link :thumbup:

 

[IanRiordan]

If an engine has a 'large' head or intake tract for it's given application, a 'short' cam or conrod can maintain airspeed below the torque peak and make it more drivable. Yes, this is a band aid but without more info such as vehicle weight, altitude, tyre size, rear susp mods etc we are all only going 'by guess or by God'.
Most races are won in the eighth mile anyway.

 

[xntrik]

Quote:
Originally Posted by killerformula
Actually I think those monte's (g-bodies in general) are quite abit lighter than previously advertised. 3200 pounds would be my guess, in fact, the cutlass is one of the lightest platforms out there for a GM if I remember correctly. You have a good place to start. Here's a link for your car's weight, scroll down to the bottom. This site just happened to have it.http://www.quickperformance.com/Tec...sus_measure.htm

K

I was referring to running weight.....AC, ps, pb, full fuel and one standard sized 170 lb. driver in the seat.

Thanks for the good link = xntrik

Studying the information on that link, I can NOT recommend it.

A Monte Carlo, Century, and Grand Prix are similar cars, yet the Monte is listed 500 pounds lighter,,,,,, and even lighter than a Pinto and Mustang II.

Also some dimensional information on Ford rear ends is incorrect.

I correct my :thumbup: for the material,

but thanks for listing it Killer :thumbup: .