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COMP CAMS Magnum 270H in a '77 L-48?

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Old 03-06-2002, 04:05 PM   #1
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Default COMP CAMS Magnum 270H in a '77 L-48?

I was wondering if anyone out there was using one of these cams in a L-48? I will be installing Dynomax 1-5/8" headers soon with true duals. With the cam swap I want to do an intake manifold swap as well. Otherwise, everything else is stock.

Any ideas on the HP increase of these mods?

Also...should I consider another cam for my setup?

Thanks,
Ted
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Old 03-06-2002, 04:12 PM   #2
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (love to drive)

You'll need a stall converter to make that cam work properly. I had a 280H behind a TH350 automatic with a stock converter and a rearend with 3.55 gears. It would not squeal tires unless you slammed on the brakes.
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Old 03-06-2002, 04:15 PM   #3
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (Stingy74)

ahhhh...well a higher stall is in the future too...would 1800-2000 be enough?
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Old 03-06-2002, 04:41 PM   #4
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (love to drive)

I would go 2500, but that's pushing the envelope for the street. Others may disagree though. What gears do you have in the rearend?
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Old 03-06-2002, 04:42 PM   #5
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (Stingy74)

I have a TCI 2400 Stall and I use it on the street all the time..I LOVE IT
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Old 03-06-2002, 05:14 PM   #6
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (Stingy74)

I have 3.08s in the rear. I'm trying to stay away having to install a trans cooler and stuff. My car is a daily driver and I'd like it to be fast, but tolerable.

Thanks
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Old 03-06-2002, 05:20 PM   #7
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (love to drive)

Quote:
I have 3.08s in the rear. I'm trying to stay away having to install a trans cooler and stuff. My car is a daily driver and I'd like it to be fast, but tolerable.

Thanks
A trans cooler is VERY EASY to install however I am not using one currently
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Old 03-06-2002, 05:28 PM   #8
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (Alwyn678)

Thanks for the info on the trans cooler install. I'm trying to keep costs down primarily. I just replaced all 4 brake calipers and master cylinder so I'm in the hole right now. I think I'd be happy with the stock converter for a while as long as the cam swap gives me some extra HPs...anyone have a guess as to what output my setup would give?
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Old 03-06-2002, 05:32 PM   #9
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (love to drive)

My engine guy makes a setup he has been doing for many many years, it's called his 325 horse 350. That's with all the fancy balancing and machining, stocks heads with dual plane intake and holley vacuum secondary carb. It used the 280H cam I was talking about earlier. Expect to be over 300hp if the engine is in relatively good shape.


[Modified by Stingy74, 3:39 PM 3/6/2002]
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Old 03-06-2002, 05:37 PM   #10
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (Stingy74)

sounds nice...I guess I'll let the seat of the pants-o-meter tell me how much HP I gained. I'm trying to build up my engine enough to beat my friend's MR-2 turbo (alterior motive) he's running high 13's and I'm running 15's now. So...we'll see what happens.

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Old 03-06-2002, 05:40 PM   #11
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (love to drive)

100hp is roughly a full second gain, but then there's the whole argument of flywheel and rear wheel horsepower.
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Old 03-06-2002, 05:49 PM   #12
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (Stingy74)

doh! well it looks like I won't be beating him anytime soon...dang turbocharged lightweight foreign sports cars :)
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Old 03-06-2002, 05:55 PM   #13
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (love to drive)

Quote:
doh! well it looks like I won't be beating him anytime soon...dang turbocharged lightweight foreign sports cars :)
Yeah but his car is still UGLY and ur is WAY :cool:
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Old 03-06-2002, 06:03 PM   #14
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (Alwyn678)

this is very true... Noone can deny the coolness of a C3 :) Heck the cool factor alone should give me the extra tenths I need in the 1/4, right? hehe
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Old 03-06-2002, 07:10 PM   #15
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (love to drive)

For what it's worth, Desktop Dyno puts you at 270HP@5000RPM and 330LB@3500. That is with a basically stock exhaust. If you switch to headers you get about 20HP and about 20LB.
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Old 03-06-2002, 10:22 PM   #16
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (love to drive)

Sounds good. This will show you something about HP. http://www.corvettefaq.com/c3/ganeyexhaust.htm
W/auto. & your gears you would probably be happier w/ Comp Cams 260H or XE256, both good for over 300 HP. More low end & no converter needed.

:cool:
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Old 03-06-2002, 11:00 PM   #17
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (compuvette)

Wow...210 hp to 290hp is a nice transition...I'm glad I did a brake overhaul. Gotta match the go performance with the stop performance :) Anyone have an idea of how bad my gas mileage will be?

Thanks for the replies,
Ted
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Old 03-06-2002, 11:16 PM   #18
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (love to drive)

HP up gas mileage down :D

I run a 270H Magnum, great cam but I have a four speed, you might be pushing
it without high performance torque converter. I do believe I read somewhere that Comp Cams says the 270H is as far as you can go stock, might want to check their web site.
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Old 03-06-2002, 11:34 PM   #19
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (MotorHead)

I may end-up sticking with the 260H like Ganey suggested...as I don't plan on changing TQ converter or rear end gears any time soon. But, has anyone done a torque converter swap themselves? If it's not too hard I may line that up for the near future and getting a better cam now.
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Old 03-06-2002, 11:46 PM   #20
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (love to drive)

I'm glad you asked the question, as I'm getting ready to do the same thing on my car. Same year and same motor. But here's my question: when do you have to change the cam bearings? Anyone? Anyone? Bueller?
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