Cam Lift

[RednBlack]

Just thinking out loud. What happens if you shave the bottom of the cam carriers? Say about .030" ? Besides a simple regrind for closing, any other issues?

And Lobster Bites from Long John Silvers tastes like everything else they cook. Don't bother.

[Mach10]

More lift won't do as much for a 4-valve head, since you'll start shrouding the valves VERY quickly.

You'll have to do something to change the timing belt length (dunno how much play the tensioner has?) to pick up the slack so you don't jump timing. 030 more lift will put you in the "interference" bracket, iirc.

[Doubt_Incarnate]

if these motors have hydraulic lash compensators, maybe it won't have any effect.

[Dave]

well, timing belt length shouldn't matter that much at .030" ... the tensioners should pick up that extra .060" and because of the adjustability of the cams in this motor you shouldn't have to worry about retarding the cams due to them being closer to the crank (as you would have to worry about this if the cam's were key'd to the cam gears)

the lash caps would probably take up that extra .030" making your work fairly useless - or worst case you'd crush the lash caps and hang your valves open nearly all the time unless you reground the cams for more then just the exhaust. (my brain just totally died and I can't think of what the un-open part of the cam lobe is called - but you'd also have to have that ground down - but then I think you'd be much better off)

Here's a funny thought ... wouldn't it be entertaining if all they did to kill the power on these motors from prototype to production was add material to the cam carriers....

--Dave.

[Fierobsessed]

Base circle.

And besides, you gain no lift at all by machining the cam carrier down. However, in conjunction with cutting down the base circle on the cams, you will gain that .030 if you do that to the cam and the cam carrier.
I think that's what RednBlackCutlass meant in the first place. Machining the carrier down only corrects the lash with reduced base circles.

Lift is the lobe peak minus the base circle measured as radiusses (radii?)

Either way, the main adverse effect is the timing belt would be a total of .120" too long, it's only about 1/8". If you offset the center idler about 3/32" down, that would do the job.

[Dave]

Base circle.

And besides, you gain no lift at all by machining the cam carrier down. However, in conjunction with cutting down the base circle on the cams, you will gain that .030 if you do that to the cam and the cam carrier.
I think that's what RednBlackCutlass meant in the first place. Machining the carrier down only corrects the lash with reduced base circles.

Lift is the lobe peak minus the base circle measured as radiusses (radii?)

Either way, the main adverse effect is the timing belt would be a total of .120" too long, it's only about 1/8". If you offset the center idler about 3/32" down, that would do the job.

Thank you! I feel so stupid for not remembering that. I also feel stupid for not calculating for both heads ... only one.

I'd seriously love to try somethin' like that too, I think it'd actually work fairly well, you'd get the higher lift, and have the benfit of being able to change the cam specs a lot more with a better grind since you're removing a lot of material.

--Dave.

[fieromadman]

Base circle.

And besides, you gain no lift at all by machining the cam carrier down. However, in conjunction with cutting down the base circle on the cams, you will gain that .030 if you do that to the cam and the cam carrier.
I think that's what RednBlackCutlass meant in the first place. Machining the carrier down only corrects the lash with reduced base circles.

Lift is the lobe peak minus the base circle measured as radiusses (radii?)

Either way, the main adverse effect is the timing belt would be a total of .120" too long, it's only about 1/8". If you offset the center idler about 3/32" down, that would do the job.

Wouldnt the tensioner accoundt for the extra .120"? If not how would you go about offsetting the middle idler for that little of an ammount? This would be a good idea for getting custom cams because you woulnt need lash caps. Is there any issues with the valve train geometry?

Does anyone have any idea how much slack can be taken up with the lifters?

[RednBlack]

Great ideas. Good side is that the cams are unsupported by keyways. Marc and I figured out the angles. You can tune these cams. That's pretty cool if you think about it.

You drop the base circle, .030", just a number, you get meat to grind on a cam. No welding. The exhaust cams have the best potential, fatter! You can adjust the up slope however you want. Same with exhaust.

[your_I.D.]

Lifters have about about 3/32 travel. Once there installed you will loose some of that. You can kind of see there amount of movement they have in this photo. http://photobucket.com/albums/a133/d...=lifter004.jpg