Max cam lift with Stock Heads

[faslane505]

Max cam lift with Stock Heads????

Was thinking about my upcoming sale of my heads last night and was wondering if stock heads will support a .606" lift cam?

 

[dnz28]

valve spring upgrade. your power band will move. its not really the just lift which effect engine performance its the lobe spread angle,duration and lift. once the valves open on a stock (restricted) cylinder head past a certain point of travel say .550 it will flow the same at .600 even though the valve travel is further. when you go with unported heads the driveability change and not for the better in most cases.

 

[faslane505]

here is my cam card....so all i may need to do is get bigger valve springs?

 

[dnz28]

valve springs and a tune.

 

[faslane505]

thanx

 

[rottenronnie]

Stock, unported GEN III heads flow 270 c.f.m. and are pretty much maxed out at .550 lift with the stock cam.
The additional lift won't necessarily hurt anything, but won't provide much in the way of power gains either.
A cam swap by itself doesn't do a great deal with the stock heads.

 

[faslane505]

my real concern was if its even possible to put the stock heads back on the truck without modification...performance is not a real concern as i am shifting fodus onto the s10 for racing and moving away from the 10. i didnt know what the max possible lift that the stock heads would take without damaging the valve train....i didnt think about the cam until last night while in deep meditation ...just didnt want to have to do a cam swap also...

 

[rottenronnie]

my real concern was if its even possible to put the stock heads back on the truck without modification...performance is not a real concern as i am shifting fodus onto the s10 for racing and moving away from the 10. i didnt know what the max possible lift that the stock heads would take without damaging the valve train....i didnt think about the cam until last night while in deep meditation ...just didnt want to have to do a cam swap also...

I don't know the particulars with your engine (have the heads been cut, are the pusrods stock length, the base circle on the aftermarket cam?, etc; etc.) but you could install a set of rockers on one cylinder and slowly roll the engine over making sure there isn't any coil bind in the springs or interference between the spring retainer and the top of the guide. That is the ONLY way to know for sure. But make sure it isn't real close at this time because once the lifters are pumped up and your 1.7s are adjusted it is likely to get even tighter in there!
It "should" be a.o.k. but there is no way for me to know from here. Maybe someone that has installed a bigger cam with the stock heads could give you the a.o.k. in your application.

It is still best to check it yourself though, I.M.H.O.