Soooo..

Back from the dead, almost
Glad to se there still activity here

I still own my 1991 6spd vette. But 3 years ago the engine killed it self.
The car has been under a cover 3 years with no engine.

Today I order a stock used vette -89 L98 for my 1991, from, the scrap.
I have some stuff I will put in it, then start to tune it.

Edelbrock lower TPI, Edelbrock runners, headers.

This time, its going to me a mild mild, no fancy, easy to tune, sniffer test friendly combo.
Im NOT going true the same hassel as the last time.

So based on this, im looking for a mild cam to work with the TPI design, and easy to tune.

What do you guys think about these options?

CC 08-501-8

Intake Valve Lift (in.)0.488Exhaust Valve Lift (in.)
Duration @ .050 in. (Deg)212Exh. Duration @ .050 in. (Deg)218Int.

LPE211 cam:

211/219 .530/.560 HR112 but im going with 1.5 rockers so less lift..

Any more tips would be much obliged..

Have a good one!!

/D

 

I had a single pattern Comp roller in my 84 Xfire. It was a 218@.050 and using 1.6 full roller rockers, had a .535" lift IIRC. LSA was 108d. Once tuned, it idled pretty well, ran well too. Make sure the spring seat pressure and pushrod lengths are correct.

 

Not sure if the 89 can handle the 108 LSA. Need 112 since it is TPI. need the vacuum for a mild build.

464 range with 1.6 seem like a good mild setup get you right under 500 lift and mild cam should be in that range at 112-114 LSA

 

the cc cam is 112 lsa.. LPE as well..

 

Yes, the heads will get some nice Beehive Pac-1218 springs and retainers. The springs should be drop-in replacements. Going to swap the spring while the heads is still on car..
Will of course check pushrod lengths when im done..

 

I'm not necessarily advocating a 108LSA for anyone, but using some information from David Vizard, that turned out to be what the cylinder head flow was looking for. Having said that, there was plenty of vacuum and the Xfire idled nicely at 800rpm. RBob could probably attest to that.
My cammed LT-5 has a more aggressive idle.

 

108 would work fine and be very torquey. 501 cam is great for you. I'd get it on a 110 lsa and have a great driver. Duration is low so overlap is low. Shouldnt be to hard to tune

 

It was torquey all right. ~350rwtq@3400rpm. Overlap was 53d.

 

LSA, ICL and overlap can greatly effect power

I have a 5.6L V8 with variable intake cam timing. I can vary the intake cam from 94 to 124 ICL and the LSA from 104-119*. Out of cams that spec 199/210* @ .050, I am seeing 390 RWTQ @ 2,980 and 296 RWHP @ 4,980 on a Mustang dyno through the restrictive factory exhaust manifolds and cats running a tune that works in a heavy truck. I gained about 8% HP and TQ when I went to a dedicated E85 tune on the same engine.

I put the truck on the dyno and made 6 different pulls to find the power curve with the cam timing altered on each pull.

Ran a pull at 0*, 6*, 12*, 18*, 24*, and 30* advanced. I overlapped all the charts and selected my intake cam timing table to match the respective best power output. I was able to gain 20-30 ft/lbs in places of the RPM band and next to nothing in others. No one setting was even close to making the curve as flat and smooth as the combined effort. Fixed LSA, ICL, and overlap will always be a sacrifice.

The engine I am talking about had the smoothest idle with a very wide LSA and retarded ICL, and liked to be fully advanced before 1,500 rpm, and liked to be fully retarded by 3,500 rpm. Advancing the cam 20* rather than 30* at about 1/2 throttle from 1,000-2,500 rpm helped fuel economy noticeably but hurt throttle response and torque. One other thing to be noted here, the smoothest idle did not offer the best throttle response and the best power/response did not equal the best fuel economy. So even with a variable setup there are still compromises.

 

You guys are so helpfull, as always

So that im not lost in translation, LSA is "Lobe Separation", and ICA is "Intake Centerline" i assume?
The stock L98 cam is 112 LSA if I remeber correct.?

 

To get it as 110 LSA isntead of 112 do I need a custom grind?

 

No comp had them available. Xr264hr-10

Similar to 501 but slightly less lift

 

What would be the benefit to run 110 LSA instead of 112? Better to tune?

 

Not much just little more low to mid range, slightly more lope.

Tune about the same

 

Sweet. Thanks!

 

I'm with Dominic and Lazard. With 360ci TPI $8d, am running a Howards Retro Roller 217I/225E, 0.495I/0.500E with 110 lSA and 106 ICL, 54 deg overlap. The 110 LSA was optimum for my configuration, and possibly 108 but chose 110. Very aggressive but controlled idle in Closed Loop at 750-800 with stock converter. Plenty of torque and upper RPM. Not an all out race cam -- just very nice for the street and does not overload the stock-ish converter. Have seen many say that 110 and lower LSAs cannot be tuned to idle with TPI. Not so for me and maybe just dumb luck. And why Howards? Because they include the bullet proof John Callies Morel roller lifters in their cam kits. Don't believe others do.
FWIW, and maybe TMI but have attached a spreadsheet I used when making a cam choice a while back. Some of the data was derived using Desktop Dyno. Many will argue that DD is not an accurate tool, and in some respects I agree. But when making comparisons of one thing (a cam) with all other variables constant, the data output is reliable because each sample is relative to the other. Hope it helps.

 

Thanks! I will look in to it