TTop Tony

Well after the gear swap from 3.08's and QJet tuning my car had the same quarter mile time as before. So I've decided to do a cam swap along with the Edelbrock heads. I figure maybe my cam isn't making power where the gears have put the rpm band. (Just a though could just be my losey driving :D ). Theres a good discussion on the C2 forum over the LT1 cam. Can any LT1ers comment on the cam. Hows the low end torque? Anybody try to use this cam. My neighbor has an original LT1 and it goes like stink. Any comments welcome.

467-Ratman

My car was originally set up to be an LT-1 clone, with the correct intake and LT-1 solid lifter cam. My motor was tons of fun to drive, but low end torque was awol, it would spin to 7k rpms without any trouble. I have read many stories about Zora Duntov and why he developed the cam to compete with the foreign cars , Ferrari , Porsche etc. at the race track. I know there are many new profiles that are way better for what you are looking for. I like the Crane Powermax series and Comp cams makes some great sticks as well. I did notice a difference in performance as I changed my rear gear from a 3.08 to the 3.70, much quicker to redline in all gears! I would recomend checking with comp cams or crane and tell them what you want the car to run and they will tell you the best setup. New heads and intake will make a big change too.

68shark

Displacement/trans/rear gears/cam/heads/exhaust/carb....all have to be selected based on a common performance objective. It may be streetability or it may be high rpm horsepower.

What are your performance goals? What is your existing set up?

Matt Gruber

i agree but
GM no longer makes the LT-1 cam. They sell a Crane version that is different. The Powermax 278, 238@.050 114LSA sounds good as used once by gkull.


[Modified by Matt Gruber, 4:55 PM 9/4/2003]

TTop Tony

"Displacement/trans/rear gears/cam/heads/exhaust/carb"
Its a 355 with a 4 speed wide ratio, 3.7 gears the heads will be edelbrock 64cc performer which will bring it up to 10:1 and the original Qjet. I have 2.5 inch rams manifolds with dual exhaust two cats and monza mufflers. I'm slowly working on the matching components thing the heads and cam are my last step. Its not a daily driver and I would like better performance down the dragstrip. I don't guess you can have more in the mid and high range without sacrificing the low end grunt but that what I'd like. I skipped the usual comp cam cam's because the extreme series say best run with 9:1 compresison or less and I will have 10:1. If someone else has a cam suggestion I'd liek to here it. I'm sure I'll call all the manufactureres when I get closer to my decision.

Brettmc

Something smells fishy. You have picked up *something* from a 3.08 to a 3.70 gear change AND qjet tuning....

Brett :thumbs:

TTop Tony

Matt
I'll definitly run teh powermax cam through DD2000 and see what happens. The torque curve from the dd2000 of the LT1 cam was amazing I thought it might be a good choice. But then again I still have a lot to learn about cams.

TTop Tony

Nope it went from 14.9 before the swap to 14.9 after. But your right the car is a whole lot more fun to drive. Its just not any faster.

Fevre

What was your speed at the end for each? Your 60' times? I agree you should have gained a few 1/10th's at least.

TTop Tony

Its too embarrassing I was hoping not to have to record it. The confusing part is when I went before the gear swap my 60' was 2.5 and this time it was 2.2. You'd think I'd have gained .3 but it was 14.9 both times down the track.

R/T .016 not sure what that means
60' 2.2
330 6.3
1/8 9.646
MPH 73
1000 12.5
1/4 14.9
MPH 93

Matt Gruber

once i put 4.56 in place of 3,23 in a 318 Duster.
It was a BLAST to drive.
But at the track, it ran the same, just like you!
Sold 4.56 next day.
.
The reason to avoid the LT-1 fake is the lift is pathetic, and with good heads you don't need longer exhaust duration. :cheers:

68shark

I didn't know the XE series isn't rec. for 10 to 1 compression. Haven't checked their site in awhile though! What cam are you running now? More cam, will give better top end but does indeed sacrifice bottom end. Your gear swap though helps to minimize that. If you have a mild cam, then a change is in order, given your goals and other mods planned/in place already. I was going to suggest headers also but note you have the 2 1/2" ramshorns which flow better than my stock 2" ones.

Fevre

Did you shift at the same rpm's? Might be losing upper rpm hp for some reason. :confused: Gaining .3 at the 60' should equate to more than .3 at the 1/4. :confused:

TTop Tony

I like my 3.7 I think I'll keep them. Like I say the only reason I mention the LT1 is most comp cams say it works better with lower compression. I wonder how much a roller cam would cost. Seems I have a Chevy Hi Perf magazine with a write up of a conversion. Now that i think of it it was pretty $$. Nevermind.

TTop Tony

Fevre
Thats what I though too I wish there was a 1/4 mile track closer maybe it was me. I shifted at about 5800 rpm. I tried leaving it in 3rd across the 1/4 and shifting into fourth. Both had the same affect. The time above I crossed the 1/4 mile at 6,000 rpm in third.

TTop Tony

"What cam are you running now"
The jasper cam is
214 224 @50
280 290 duration
443 465
LCAI 107 LCAE 117
I'm not sure if that mild or wild. It seems to fit in between a lot of cam specs I see. what do you think?


[Modified by TTop Tony, 4:12 PM 9/4/2003]

Matt Gruber

Have you considered AFR, Canfield, or Pro Action heads?

TTop Tony

I actually bought these heads off a friend of mine for $200. They just need a valve job. But if they turn out to be bad AFR is at the top of my list. I also think the chevy fastburn heads look interesting too.

Glensgages

TTop Tony, maybe I can help.

#1- .016 RT means that your car 'tripped' the starting beam sixteen/thousandths of a second after the light turned green, VERY GOOD for a first-timer. (If your track has the 'old' timing system, your .016 was WAY RED; which was it???)

#2- it IS entirely possible that you DID pick-up .3 in the 60', yet ran the same ET (i.e.; you 'lost' it back down-track), especially if your motor doesn't make much 'smoke' at the higher RPMs. I'll try to 'splain this...
Say I gave you a 10-speed pedal bike, to run the 1/4-mile, but I'd ONLY let you use gears 1 thru 6, on one run, then gears 5-10 for the second run.
On the first run, you'd boogie right off the line, but be 'wound-tight' well before the finish-line. you'd have a killer 60' time, but the last 1000', you'd not accelerate any, if at all; you can only go 'SO-fast' in 6th gear.
For the 2nd run, you'd struggle mightily off the line, with a horrible 60' time, but at the 1/8-mile, you'll be going faster & faster, because you won't be out of 'leg-speed', or 'power'. You'll continue to accelerate thru gears 7, 8, 9, and 10, too.
It is possible, or probable, that what you 'gained' in the 60' with 3.73s, you 'gave-up' the further you went. Expand the problem; if we raced a FULL MILE, the 3.08s would be much better. Even THEY might be 'too-much' gear; Top Fuelers once ran 2.6:1 gears to hit 290 MPH in the late '80s....
If I've confused you, send me an E-mail, where I'll try to 'splain-it better....

(P.S.: I run a 10.3:1 355" in my Z28 w/ iron DART heads, Victor Jr, 750 dbl pump Holley, etc. I ran the 'old' CompCams 292H (.501", 244* @ .050", 292 advertised, 110-112 (:confused:) LSA. It pulls to 6500 RPM, has a rump-shakin' idle, yet has caused NO valve-train problems over 14+ years. If your C3 is NOT your daily-driver, might wanna consider this one.....)
:thumbs: :chevy

TTop Tony

The lights were very flaky that day. We had a huge storm blow threw the night before and they weren't working well at all.

Actually Glensgages that does make perfect sense thanks.


[Modified by TTop Tony, 6:18 PM 9/4/2003]