Comp Cams 3692 Lobe?
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224@.050...a lot more lift and a faster ramp, especially over .100 lobe lift, than the XE-R. Yet a hydraulic roller, and pretty small. Should flow much better than any equivalent XE-R...
EXCEPT...
that high lift may require a lot of pressure over the nose to prevent valve toss. Which is the root of my question. In real life, can it make 7000rpm? In real life, can it pass emissions? In real life, what kind of valvetrain is necessary? Does a 1.29"x1.770" spring have chance?
If so, especially if it can avoid titanium valves...maybe it is a good street choice for those of use willing to change springs annually.
EXCEPT...
that high lift may require a lot of pressure over the nose to prevent valve toss. Which is the root of my question. In real life, can it make 7000rpm? In real life, can it pass emissions? In real life, what kind of valvetrain is necessary? Does a 1.29"x1.770" spring have chance?
If so, especially if it can avoid titanium valves...maybe it is a good street choice for those of use willing to change springs annually.
solid cams arent very aggressive at all near the seat. the clearence ramps taking up the lash is usually pretty slow
If your putting the titanium valvetrain together, and dont mind "trying soemthing" with titanium, then give it a whirl
If your putting the titanium valvetrain together, and dont mind "trying soemthing" with titanium, then give it a whirl
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Originally Posted by GrannySShifting
I think that will beat the **** out of your valvejob, and love buncing the valve off the seat
I'd run the lobe with solid roller lifters. Set a light lash setting of .002"/.004" when cold then put some springs on it in the 180# seat range. Nose pressure is not as important as seat pressure, of course I come from the Harvey way of thinking.
Chris
Chris
I read an article about running solid lifters on hydraulic lobes a while back. I think this is a real bad idea. Just like Granny pointed out the solid lobes have a much softer lobe flank allowing much softer initial opening and closing. The hydraulics do not have this because it is the lifters responsibility to absorb this impact. Now, you could run a hydraulic lifter on a solid lobe, unless ofcourse you are talking about something with a rediculous lobe intesity.
Its been done before Nick. Not a 20,000 mile lasting street setup, and lots of seat pressure will eventually beat up your vavlejob though
The LSK is a minute bit slower rated intensity then XER, I know that, but I wouldnt want something as quick as an XER cam at 7000 rpm with a heavy valvetrain, if I had a choice. With the additional spring pressure needed to control it on/off the seat I just dont like it - not for a real street car.
Sides theres lobes out there with the best of both worlds
The LSK is a minute bit slower rated intensity then XER, I know that, but I wouldnt want something as quick as an XER cam at 7000 rpm with a heavy valvetrain, if I had a choice. With the additional spring pressure needed to control it on/off the seat I just dont like it - not for a real street car.
Sides theres lobes out there with the best of both worlds
Straub, got any thing thinner then that? What are the limits of hardened steel seats as far as thickness?
Know a relatively cheap place to get berrylium spring seats, Ive heard they can go quite thin
Know a relatively cheap place to get berrylium spring seats, Ive heard they can go quite thin
Originally Posted by DAPSUPRSLO
Now, you could run a hydraulic lifter on a solid lobe, unless ofcourse you are talking about something with a rediculous lobe intesity.
Granny, No. Thats what we were asked to make. Case depth is .020" So you could turn them down .010" on each side and get .035" without breaking through to the soft core.
Chris
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Whether you need the spring on the seat, nose or both is a function of the rates of acceleration and jerk. The 3692 looks more violent over the nose, based on the limited data I have, then some solid rollers that have greater duration at .050 and similar duration at .020.
Questions...solid rollers are rated at .020 or .015 tappet lift, say .007-.012 at the valve. Hydraulics are rated at .004 or .006. How does that related to valve movement?
Questions...solid rollers are rated at .020 or .015 tappet lift, say .007-.012 at the valve. Hydraulics are rated at .004 or .006. How does that related to valve movement?
I understand that on a .750" lift solid lobe a hydraulic lifter will not work. However, most of the solids for ls1's are not in this category yet. I would have though the solid lifter wouldn't work on a hydralic lobe just because the lobe flank is not as soft on a hydraulic lobe. I guess you have to take into acount that in general, not necessarily in the ls1 world because I have been told by Jason over at Thunder that the LSK is as agressive or more agressive then most ls1 solid lobes he has seen, solid lobes are more agressive and would collapse a hydraulic lifter.
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It is my understanding the hydraulic lifters have significant limitations in their ability to deal with stiff valve springs, the type of valve springs you need to handle aggressive cams. That, and their higher mass, are the reasons, as I understand it, that they can't handle the loads of a solid lifter.
Isn't it the spring load that keeps the hydraulic lifter in the preload range?
In the old days a lot of cars had solid lifters: LT1s (1970 vintage, Z28s, Boss 302s, Hemis (the 426cid kind), 435/427s (big-blocks), L88s, I think the AAR Cuda/TA Challenger, etc. I'm not sure why they totally went away. Maybe when a Covette was lucky to do 16.8@84 (late 70s) in the quarter, they didn't seem important.
I can't speak for every car, however my Supra TT has solid lifters (actually the lifter is a bucket over the valve spring and setting lash is roughly the same difficulty as changing LS1 heads--ok, a slight exaggeration).
I would have liked to see a grind that was in the 273 range at .005, 230@.050, and 160@.200 with maybe .330 or .340 total lobe lift. Lots of area under the curve without to much extra lift.
How does this solid sound: 263@.020, 235@.050, 154@.200, .347 lift and smooth enough for 2.0 rockers.
Isn't it the spring load that keeps the hydraulic lifter in the preload range?
In the old days a lot of cars had solid lifters: LT1s (1970 vintage, Z28s, Boss 302s, Hemis (the 426cid kind), 435/427s (big-blocks), L88s, I think the AAR Cuda/TA Challenger, etc. I'm not sure why they totally went away. Maybe when a Covette was lucky to do 16.8@84 (late 70s) in the quarter, they didn't seem important.
I can't speak for every car, however my Supra TT has solid lifters (actually the lifter is a bucket over the valve spring and setting lash is roughly the same difficulty as changing LS1 heads--ok, a slight exaggeration).
I would have liked to see a grind that was in the 273 range at .005, 230@.050, and 160@.200 with maybe .330 or .340 total lobe lift. Lots of area under the curve without to much extra lift.
How does this solid sound: 263@.020, 235@.050, 154@.200, .347 lift and smooth enough for 2.0 rockers.