Author Topic: pontiac 400 with Crower 60240  (Read 3568 times)

Offline Marx3

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pontiac 400 with Crower 60240
« on: November 01, 2014, 11:52:57 AM »
Hi, I recently rebuild my L78 400 engine and I want to know what to expect from the engine. I dont need to know how much horsepower it makes, it's nothing like that... I just want to know what to expect.
specs:
1978 L78 400 with 6x8 heads.
Everything on the engine is completely rebuild to stock except the heads have been milled .050, chambers are measured at 89 cc. This should put the CR around 8.4-8.5 ( ? )
I put in a Crower 60240 cam per Cliff's advise.
Ignition is set at 22 degrees in idle advancing to 35 total.
Exhaust is a true dual with some sort of glasspacks.
So completely rebuild " as new" engine except for a bump in compression and the cam.
Engine sits in a  stock 1978 Trans Am with th350 and 2.56 rearend.
Should this car not feel quick and "fresh" ? I know it propably wont ever do 13 or 14 second ET's, but it should at least feel quicker, right? When launching WOT form at stop, should it not spin the wheels?

( reason I ask, is the Qjet on it is not working properly, so right now it WONT even spin the tires when it rains...

Should this car not feel pretty "fresh"

Offline 429bbf

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Re: pontiac 400 with Crower 60240
« Reply #1 on: November 01, 2014, 12:45:03 PM »
i don't  think its going to feel that impressive. because of the gear ratio 2.56 is pretty tall and thats not really that light  of car. i think that car weighs like 3800 lbs. i should be pretty nice to cruise around 75mph .i think it would a tire destroyer if you had like 3.25 or close . fwiw

Offline Marx3

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Re: pontiac 400 with Crower 60240
« Reply #2 on: November 01, 2014, 01:29:41 PM »
yeah I think you are right that it is not going to be a fast car, I dont think it was from the factory back in ยด78... at all actually :-) It weighed in at 3600 this summer with no driver, no sparetire and an almost empty tank.
I dont care much about the 0-60 times, the ET's etc, I care the most about it ability to spin the tires when pedal is pushed to the floor.

Could these cars even do that when they were new? I suppose you could powerbrake them, no problem, but would they spin the tires freely when going WOT from a stop...


Offline 429bbf

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Re: pontiac 400 with Crower 60240
« Reply #3 on: November 01, 2014, 04:06:58 PM »
my buddy had on of these we called it the one wheel wonder . he had to crank the wheel to the left and he could get the right rear to spin. it was a nice car to cruise down the interstate . the car had an unbelievable top end.  but it took a long time to get there.the bad car back then was a 68-9 camero it had a 302 .the guy put like 5.5 gears in it . he could shift 4 times and only move about 10 ft.fwiw

Offline Marx3

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Re: pontiac 400 with Crower 60240
« Reply #4 on: November 02, 2014, 03:17:06 AM »
stupid gears! :-)  I better start saving some money for a 2.93 or a 3.08. My current rear sings a little at 50 anyways. Or put in a manual from a diesel Crewcab. Those boxes got about 5:1 first gear IIRC