too mild camshaft

-
N

Nokke

Active Member
Joined
Dec 31, 2006
Messages
42
Reaction score
0
Location
Motala Sweden
I Have question for you guys what should i choose for a camshaft to reach 600 hp?? or do you think its even possible with a new camshaft??

My combo is now

408 stroker La block

Eagle 4340 crank
Eagle H-rods
Srp 10.5 pistons

Indy cylinder heads 210cc 2.10/1.65 valves ported & polished
the heads flows at 650 lift 307/230

carb 1050 dominator
manifold indy matchported to the heads

Camshaft comp cams xr286r 0.50 duration 248/254 576/582 lift 110 lob sep
td machine rockers 1.6

tti 1 5/8 to 1 3/4 stepheaders

engine driven and tested in bench to 555,3 at 6300 rpm & 527,8 ft at 4900 rpm
 
You should try an aggressive solid roller.
Your heads flow more than enough to hit the number IMO.
I wonder about that carb maybe being too big.

headers....hmmm....
 
mopar340dave said:
you don't wanna here this but,,,,your static comp is possibly too low to take advantage of the rest of the combo...I would want around 12-1 static with a .630" lift solid roller, like 26? duration at .050"

carcraft/Steve Dulcich used this to do it, I think:
http://cranecams.com/?show=browsePa...-360 C.I.&partNumber=698811&partType=camshaft

you need to calculate your dynamic compression ratio
Click to expand...



Whatever they did, If they dyno tested it at the happy westech facility you can throw the data in the trash or multiply it by about .85-.87 to get the REAL numbers. Seen more than one engine dyno run at westech and then at another facility. It ran the MPH consistent with the lower numbers.
----------------------------------------------------------------

For the OP. I'd only be concerned with the numbers at .500-.550 and below. What your heads flow at .650 isn't of concern when the cam is only opening a gross number .050 below that number. Figure lash and bad valvetrain angles and it's much less at the valve, likely a net of .550-.560 if you are lucky with the 1.6 rocker.

That cam works pretty well in stroker set ups
 
crackedback said:
Whatever they did, If they dyno tested it at the happy westech facility you can throw the data in the trash or multiply it by about .85-.87 to get the REAL numbers. Seen more than one engine dyno run at westech and then at another facility. It ran the MPH consistent with the lower numbers.
----------------------------------------------------------------

For the OP. I'd only be concerned with the numbers at .500-.550 and below. What your heads flow at .650 isn't of concern when the cam is only opening a gross number .050 below that number. Figure lash and bad valvetrain angles and it's much less at the valve, likely a net of .550-.560 if you are lucky with the 1.6 rocker.

That cam works pretty well in stroker set ups
Click to expand...


maybe so...I don't know, but the cam needed to run the numbers is still wanting a higher static comp ratio. the 260ish duration requires it

what is the dynamic compression ratio now?
 
I like CB's idea of more cam and a 1.6 rocker. Compression is a bit light for much more cam but, I'd bve looking at another cam starting about 260 @ .050 duration and .600 lift at a min. for starters.

Rather than piston change, is a head milling possible?
 
Sorry to impose on your thread but, Is 600hp on a 2 bolt main cap setup asking for trouble? I've heard in other threads that those numbers are right at the limits of a 360 block.
 
currently dynamic compression is down to 7.75/1

maybe get a cam that closes the intake sooner...the power is already down with that static comp to start with, though comp says that 10-1 is fine...I don't know what they base that on.

63 dartman, 600 hp is no prob for the block, I believe the limit at this level is more related to rpm than the actual number of horses. the higher you spin the crank, the harder it is to keep in one spot
 
63dartman said:
Sorry to impose on your thread but, Is 600hp on a 2 bolt main cap setup asking for trouble? I've heard in other threads that those numbers are right at the limits of a 360 block.
Click to expand...

Yes, but theres ways around it to help it live there.
 
since your bottom end is similar except for stroke and you have better top end, it would be cool to see how your engine would react to the cam/rocker ratio combo they used in this 318. he used a combo of 1.7/1 intake and 1.6/1 exhaust rockers to achieve .622"/.597" at the valve with 247 degrees at .050" lift. lobe sep was at 105 degrees

http://www.popularhotrodding.com/te...gine/mopar_performance_rt_cylinder_heads.html

I would contact someone who grinds em cutom like clay smith and tell em what you got and what you want....they'll tell you what ya need to get it.

http://claysmithcams.com/
 
63dartman said:
Sorry to impose on your thread but, Is 600hp on a 2 bolt main cap setup asking for trouble? I've heard in other threads that those numbers are right at the limits of a 360 block.
Click to expand...

Maybe but what is gonna give you trouble is detination which will give you cap walk which will hurt the Main caps.

I agree that you don't have enough compression for a bigger cam.What is the compression of your combo?What fuel do you run at the track?What does the car weight etc....

This question is for the original person who posted the tread.

DSC_3565wtmk[1].jpg
 
More static compression to start. I'd be looking for at least a full point more but preferably 1.75 more. The cam's not bad with the 1.6s. But with those heads I would have been looking at something like the 308R. No need for a dual pattern cam with them. IMO, at 550 it's a little soft as it sits anyway. I'd expect more from it as it sits now.
 
the problem is that i dont know the compression ratio exactly! wich is very bad by the way. But im going to count it out. But i now its rather low on compression that i now for sure . the engine is dynoed in a superflow bench and ran on shell v-power 99 octan gasoline and the wieght on car is 3400 lbs. i have been thinking of milling my heads for the compression but i dont want to go over 12-1 compression because i want to drive on v-power gasoline because that is ordinary gas station gasoline that i cheap.. thanks for all of your answers
 
That camshaft is 576/582 lift with 1.5 rocker arms. Lift with
1.6 rockers is 614/621. That may be the reason Comp suggested
that camshaft. He did say he was using 1.6 TD machine rockers.
I have a Comp catalogue and just checked to be sure.Sounds like
that is going to be a strong motor.Good luck and keep us posted.
 
I consider that cam a street cam in terms of it's profile. That doesnt change with the greater lift and duration of 1.6s. Which was why I think it would make more power with the good heads with a more racey single pattern deal. I dont see any issue with running the current cam at 11 3/4:1 static on pump fuel.
 
I agree with Moper except that the duration does not change with the rocker ratio change, just the rate of lift.....the 1.6 ratio increases the rate and amount of lift with no effect on duration.
 
mopar340dave said:
I agree with Moper except that the duration does not change with the rocker ratio change, just the rate of lift.....the 1.6 ratio increases the rate and amount of lift with no effect on duration.
Click to expand...

Sorry but a higher ratio rocker does affect duration at .050 a little due to bringing the valve up to .050" lift quicker. It would also have to affect the total duration since it's rate of lift is faster. Although it is so minimal it probably wouldn't be noticed.
 
fishy68 said:
Sorry but a higher ratio rocker does affect duration at .050 a little due to bringing the valve up to .050" lift quicker. It would also have to affect the total duration since it's rate of lift is faster. Although it is so minimal it probably wouldn't be noticed.
Click to expand...
It would still have zero effect on the duration figures as measured at the tappet. It only changes rates on the valve side of the fulcrum.
 
My 2 cents too is at least a full point more CR too. I went 11.7 static after mill work and I am a little less cam than I think you are going to need to make 600 hp.

I am not sure at this point how much you would want to cust the heads if at all, and then you still need a very good gasket I feel like a cometic etc to seal her up. Maybe there is another option, but I think more cam and a little more squeze...
 
doktor_x said:
It would still have zero effect on the duration figures as measured at the tappet. It only changes rates on the valve side of the fulcrum.
Click to expand...

I didn't say it had any affect at the tappet duration. After all the duration measured at the valve is all that matters and it is affected. Ever so slightly but it is affected.
 
fishy68, the duration (amount of time that the lobe lifts the lifter, measured in degrees) is not effected by the rocker ratio.

The "duration" is simply a measurement of where lift starts and ends, not how much.

The "duration at .050" will change slightly because the rocker has a higher ratio and will have the valve open a little bit further, faster. Duration at .050" lift is a tool (so to speak) to give you an idea of how aggressive the cam lobe is.

The "advertised duration" is the actual duration of the cam.
The "duration" will remain the same while the lift increases across the board.

In other words, the duration of the cam does not change, the amount of lift does.
 
mopar340dave said:
fishy68, the duration (amount of time that the lobe lifts the lifter, measured in degrees) is not effected by the rocker ratio.

Of course it's not. I never said it did.
Click to expand...
The "duration" is simply a measurement of where lift starts and ends, not how much.

Yes that's right. But it is a measurement taken at the valve, not the cam lobe.
Click to expand...
The "duration at .050" will change slightly because the rocker has a higher ratio and will have the valve open a little bit further, faster. Duration at .050" lift is a tool (so to speak) to give you an idea of how aggressive the cam lobe is.

Understood, although I'm not sure calling it a tool is correct since it's a rating just like total duration except it's more precise
Click to expand...
The "advertised duration" is the actual duration of the cam.
The "duration" will remain the same while the lift increases across the board.

Here is where the problem lies. It is the duration at valve lift. Not at the cam lobe.
Click to expand...
In other words, the duration of the cam does not change, the amount of lift does.
Click to expand...

Yes the cam duration doesn't change. The advertised duration is the amount of duration at the valve at a certain lift. Some mfg.s spec it at .004 lift and some at .006 and others at .008.With that in mind the valve duration is changed even if it is a small amount. I know this positively because I did some testing recently with 1.5 ratio rockers and 1.6 rockers and with the 1.6 rockers the valve duration was increased.

So to reiterate I fully understand that different ratio rocker arms don't affect lobe duration. But they do affect valve duration (even if it is only 2-3 degrees) and that is all that matters.

This has gotten way off subject from the OP so this is my last post on it. Sorry to muddle up things with technicalities Nokke.
 
You must log in or register to reply here.
-

Back
Top