how much cam

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408stroker

408stroker
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i got a 408 with ross pistons #99789 on a 6.123 rod with 4 in stroke and edelbrock heads any one also have this and what cam you using kinda worried about valve clearence
 
Any over-the-counter ross pistons I've delt with have ample room for .600"+ lift. I'm assuming the heads are unported since you did'nt mention otherwise. So more lift would be unnecessary. Unless you get into some huge duration numbers you'll be safe. A final check with cam center-lined is always manditory. My .02$.
 
Shouldn't have a problem with valve to piston. You have plenty of compression. Hope this isn't a pump gas engine. You'll have some problems with cylinder pressure with short duration cams.

Keep in mind that a stroker will eat up duration as it's 10% larger than the regular 360. Step up the duration. I know that the 60404 lunati and Comp XE275HL and 285HL work good in stroker engines. Should get in the 500-540 range depending on other parts.
 
There is a thing called lag time and unless you are going roller more lift beyond the heads flow is not a bad thing.
See when a flat tappet cam hits it's max lift it immediately closes again unlike a roller that slams the valve open and holds it open way longer allowing the port to flow what ever it can but longer [more cylinder filling] which is the idea with putting more flat tappet lift then the heads will flow.
Reason is... flat tappet cams spend way more time opening then they do at max lift. So if the heads stall at .450 [typical factory sb heads] then raise the lift to .500 or so. However [there is a point when too much lift will no
longer help, or at least to your benefit/application.]
This should help with your decision.
 
I agree but you can run a smaller cam with more duration and make more power like a stock eliminator engine.
 
NO FRIENDS said:
There is a thing called lag time and unless you are going roller more lift beyond the heads flow is not a bad thing.
See when a flat tappet cam hits it's max lift it immediately closes again unlike a roller that slams the valve open and holds it open way longer allowing the port to flow what ever it can but longer [more cylinder filling] which is the idea with putting more flat tappet lift then the heads will flow.
Reason is... flat tappet cams spend way more time opening then they do at max lift. So if the heads stall at .450 [typical factory sb heads] then raise the lift to .500 or so. However [there is a point when too much lift will no
longer help, or at least to your benefit/application.]
This should help with your decision.
Click to expand...

I agree with ya here, except, the tendency to go with that thinking will often have alot of people getting a very large cam instead of the right one on that thinking or like BJR said, a smaller one that doesn't take max advantage of the head but will still make power if not more.

Of course, everything is combo dependent and depedent on what your doing with the car/engine. Also, how hard your tryin to hit it.
 
BJR Racing said:
I agree but you can run a smaller cam with more duration and make more power like a stock eliminator engine.
Click to expand...

Only if your running stock eliminator.
Which they would run different if they had the option right?
This needs stay on corse for a 408 strt/strp.
Stock eliminator cams are not for driving they are for racing and most have been proven on a dyno that while they maintain a solid flat hp/tq curve they do not produce as broad a band and as much total power as a higher lift cam that also has better manners due to a lot less duration&cl
I call stk eliminator cams 'light switch cams'
But now thats general too. You can if your smart trick your way around things.
Not really into arguing this, it is what it is for it's app.
 
rumblefish360 said:
I agree with ya here, except, the tendency to go with that thinking will often have alot of people getting a very large cam instead of the right one on that thinking or like BJR said, a smaller one that doesn't take max advantage of the head but will still make power if not more.

Of course, everything is combo dependent and depedent on what your doing with the car/engine. Also, how hard your tryin to hit it.
Click to expand...

Duration is a different story ,and while very important, with different rocker ratios, rollers, fast ramp speeds can be overcome.
Then there's center line...........

A cam can make or break any motors potential.
 
NO FRIENDS said:
Only if your running stock eliminator.
Which they would run different if they had the option right?
This needs stay on corse for a 408 strt/strp.
Stock eliminator cams are not for driving they are for racing and most have been proven on a dyno that while they maintain a solid flat hp/tq curve they do not produce as broad a band and as much total power as a higher lift cam that also has better manners due to a lot less duration&cl
I call stk eliminator cams 'light switch cams'
But now thats general too. You can if your smart trick your way around things.
Not really into arguing this, it is what it is for it's app.
Click to expand...

I didn't say to run a stock eliminator cam I said to run a cam that has more duration on it with less lift, if the engine is going to have a valve to piston clearence problem then move the CL back and run more duration.
 
NO FRIENDS said:
Duration is a different story ,and while very important, with different rocker ratios, rollers, fast ramp speeds can be overcome.
Then there's center line...........

A cam can make or break any motors potential.
Click to expand...

Absoultey! I'll not argue the verity of choices out there that can be made. HOwever, hitting the max on a cam choice is not allways the best choice.
 
BJR Racing said:
I didn't say to run a stock eliminator cam I said to run a cam that has more duration on it with less lift, if the engine is going to have a valve to piston clearence problem then move the CL back and run more duration.
Click to expand...

You make a good point there BJR. You can load up on duration at most any given amount and have the cam cut to delive a modest lift to suite the head and/or catogorey class in racing and still have the abilty to run low 11's in a full bodied car.
 
You leave out a whole bunch of info... tire, gearing, trans, type of driving, fuel, etc etc etc. The more info you can give the better.

I'm going to generalize on some. Say a 27" tire, 3.91s, and tight street type 10 1/2" convertor in the 2500 rpm brake stall range? Car runs pump high test, and you drive it 80 on the street? And it's a flat tappet engine (no lifter bore bushings)?

Big duration numbers make power for the reasons stated above. But, the caveat is they can be hard on valve springs because they have to have very heavy springs to control the rapid changes in direction as the lifter moves over the lobe. Same deal with some fast rate of lift designs that are popular now. It really doesn't make sense to me to get really exotic here. The build is sound and fairly easy. My feeling would be to go with a solid flat tappet, in the 265-270° @ .050 range, with lifts in the .580-.600 or more range. That will work well with basically stock RPMs, and keep the cylinder pressure down to acceptable to stay out of detonation. Truthfully, I'm not sure I like that piston choice. For a heavy street, once in a while drag race, I would have gone with a Diamond with the 18cc dish set at .010 proud. As it is with the Ross, you're already sacrificing some quench distance because they spec it for .017" down in the hole. With the gasket I normally use, that's .050 quench. I prefer to run mine at .030-.035. Doesnt sound like much, but it can make a difference when the fuel choices get cruddy.
 
The only thing that I would be worried about with the cam that Moper has suggested is if the valves would hold the amount of spring pressure that would be required. Unless the CL is moved back I would think that a cam with this amont of duration wouldn't be too street friendly at low rpm's. Even with the larger CI's.
 
No kill like overkill! LOL!

Are those Edel. heads ported?
 
BJR, I spec lobes from Engle that are a little easier on springs.. specifically fast rate of lift but designed for the ford lifter size...lol. The last one called for 340 over the nose and it was a big block. I'm running 360lbs open and the car is a pump gas 505, making just shy of 620hp with a modified 6bbl. A similar .904 lifter designed ultra fast rate solid lobe will want 400 or more which I think is just too much for any street car that idles at normal levels. The 505 is 4.25 stroke, but idles clean at 900rpm and the car has power brakes. Not sure how effective they are, he didnt tell me that when we discussed cams..lol.
 
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