427V8BB

Just out of curiosity what do you guys need to change to run these high lift cams to not get side load or valve float. just rockers and some lifters?

Drew03tx

valve springs as well

427V8BB

what rockers and lifters and springs are these guys using and do 700 lift cams impact fuel economy bad?

RACER7088

You need a stable lobe and light Ti valves and good springs and definitely decent shaft rockers with a roller tip like the Jesel Sportsman or better or crower steel LS7 rockers or T and D etc. and also a nice heavier wall 3/8ths or larger diameter pushrod in general. With a more rigid rocker you can run a little stiffer valve spring to control the higher lift motion better. Better yet get some spintron time with a professional or copy a known system or ask someone like Comp Cams Billy Godbold what is even in the ball park. It's a complete and total system you are looking at and of course it's never cheaper to have more lift AND more reliability!

Drew03tx

not sure on the lifters and rockers, I have a 660 lift cam and use stock rockers and lifters, just changed the pushrods and valve springs. Look up some valve springs that have the correct spring pressure for that high of a cam

Dan_the_C5_Man

A question back at you.. Why??

Most HP and Tq goals can be achieved witbout crasy lift numbers.

427V8BB

Drew03tx

a 660 lift cam (most people refer to them as stage 4 cams) sounds pretty aggressive and comes with its fair share of bucking when driving. So bigger is only going to amp that up

realcanuk

With a 770 lift cam I would just save money and keep the stock valve train. You will hate the car so much you will never drive it anyways.

Seriously though. You've been posting questions all over the forum that obviously show you don't really know what you want or need. You should sit with someone who knows what they are doing and discuss your goals for the car, and have them help you piece together the proper combo to get there. It really sucks to spend all kinds of money and then not like the results.

1LEThumper

Reliably a OE rocker arm doesn't like to go much past 0.650-0.660 lift or it starts to hang at the end of the rub pad and can start doing some weird things.

I understand Comp Cams is working on OE style rocker arm that should be able to go past that and correct some of the geometry issues but nothing has been said as to a price or release date yet. http://markenperformance.com/n-9281-...e-springs.html

That is about all I have seen showing it. Again nothing official has been posted.


You would need to take a very careful look at the valve stem length, seal install height, coil bind and make sure that nothing is going to crash into itself when you start talking about big lift cams. Other than the the rocker that is going to be the harder part to get setup right.


Billy at Comp would be a good contact to speak about it with too.

Michael_D

T@D makes a bolt on roller tipped rocker for rules restricted engines that run + .700 lift. With that much lift though, the engine built requirements will start snow balling real quick. Don't do it. Totally unnecessary.

427V8BB

1LEThumper

Jesel does as well and they are super nice and around $255 ea rocker ($4000 a set)

427V8BB

Bad_AX

Pretty much everything including pistons. This is going to be a big money project if done right.

This ^^

1LEThumper

http://www.dragzine.com/features/pri...ms-from-jesel/


Those...called on them just a few months ago. Biggest reason is that they are a steel rocker which is always going to be more money than the aluminum ones just due to machine time and material.

MTPZ06

I emailed Jesel in March of last year, and they had said their "best price" was $220/ea. Even at $3500 a set, that's still just cost prohibitive for most considering we don't really know anything about tip weight, MOI, what springs are required to maintain OE redline, spintron data, etc. Jesel makes some of the best stuff out there without question, but these are still a bit of an unknown commodity at the moment.