Gary U

iTrader: (1)

I did a search, and did not see what I was looking for. After five years and 14,000 miles of ownership, I am looking to increase the performance of my Z28. I am looking at cams and like the TR220 114LSA. My concern is the high lift and "fast" ramps. I use my car for road racing track days and am worried about valvespring fatigue or other problems with the higher lift cams. On a typical track day I see well over 100 miles which is like hundreds of quarter mile passes in a single day(for the engine at least).

Should I not worry about fatigue? Are there moderate performance cams available with lift in the 0.530" range? I know the hotcam falls into this category, but I think the idle will be too rough for me.

Thanks

PewterEllis1

The Comp 218/224 can make good power. Read about someone here who made well over 400rwhp with stage 1 heads. Should idle good on a 114lsa.

Ragtop 99

iTrader: (7)

THe older Comp ramps (pre XE and XE-R) are less agressive. If you are in the high rpm range a 220/220 115 with the old lobes will idle like a TR 220/220 114.

Are you worried about fatigue on race day or just a shorter spring life? I would have guessed that as long as the oil is flowing and not overheating that you would be ok. If it is spring life, change them once a year and enjoy the benefits of the TR cam.

I follow no 1

iTrader: (6)

I have just over 400 rwhp with a 510 lift on intake and exhaust.I have stage 2 heads and all the bolt ons.I also just found out that my springs are weak so it could be more.My cam is a 228 234 510 510 114ls.It has a lope with low idle loud exhaust and no cats.After I changed the exhaust and now it is hard too tell that it is in there.I may be willing to sell if you are interested,let me know.

Jantzer98SS

iTrader: (54)

I'm running 10's with the first generation 224 .535 lift MMS cam. It idles a little rough on a 112 lobe, in fact worse than their 229 .578 114 they have now. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> I think for alot of people, the lower lift cams are better for reliability and durability of the valvetrain. For instance, I'm using the comp 981-16 springs (very low seat pressure) NOT the new 918's, and stock pushrods. I've never had a problem. If you don't want to change springs often/ever then go with the lower lift cam. I don't think THAT much power is left on the table.

Use a single pattern cam around 220-224 on a 114 and it'll idle fine. They are the XE lobes from comp.

99 Black Bird T/A

iTrader: (4)

Comps 216/220 has ~.530 lift it's ramp action isn't as harsh as an XE or XE-R. While this cam is a little smaller than the TR-220, something similar to it with a few tweaks might be worth thinking about.

Tin Indian

Moore Performance will get you a cam with whatever cam lobe you select in the Comp Cams "Xtreme RPM" profiles. You just select the Lobe # ie:

#3752 gets you a 218 duration / .527" lift lobe
#3767 gets you a 220 duration / .531" lift lobe
#3768 gets you a 222 duration / .532" lift lobe

For a stable idle, get it in a 114 LSA and a single pattern, ie:
220/220 .531"/.531" 114 LSA

You can use the Comp Cams "drop-in" replacement 918 springs. Use your stock steel retainers. They should last a long long long time with the valve lifts of these lobe profiles.

Although, I think the Thunder Racing TR-220 cam (220/220 .553"/.553" 114 LSA) is a better cam and will idle better, these low lift lobe numbers above will certainly let your valve springs last as long as your stock setup.

Ron,

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<small>[ November 23, 2002, 11:46 PM: Message edited by: Kimchee and Rice ]</small>

Nasty N8

iTrader: (33)

Gary I think "I follow no 1" is on the right track. Just with a bit more lift. You will like the power of more duration. Split226-234 525or 530 lift on 114 for good idle. We can have any size custom ground for you.
Nate

Gary U

iTrader: (1)

Thanks to all for the info. I was doing a little browsing on the Thunder website and see that they have a Comp cam listed as 218/224 .527/.534 114LSA. This would seem to be somewhat similar to the TR220 I was considering with lower lift and duration which is a little more and less. Does anyone have experience with this cam? I was also surprised to see that "computer tuning needed" with this cam, yet the TR224 112LSA does not (with M6). Do the fast ramps of the Thunder cams result in less overall duration even though the @0.050 numbers are the same?

H82BBad

I am running a 216/220 comp with .52x/.53x lift
my best so far in the 1/8 is 7.22@ 3490lbs in 200 feet of density altitude.

its a lot better cam than I thought it would be.