72 351Cleveland 2v issue Help....

cobracobra50 · Jan 24, 2008

Hi everyone I have a problem with my 351c and would really appreciate any help in figuring this one out.
So the story is, I had just rebuilt a 1972 351C, Bored 30 over, new bearings ( main, rod and cam ) cam is new and is a stock grind, no modifications to valve train aside from putting all fresh valves, seals lifters and so on.
The motor is a 2v, with a 4bl Edelbrock performer intake , the carb is of a replacement kind ( Holley 80457 ) from what i know is 600cfm.
carb was freshened up ( seals, gaskets , rubbers, needles valves and so on )
The problem is that this thing just wont run well, it's missing, no power sluggish
needs to be warmed up for at least 30 minutes before you could even move ( or it dies and gets hard to restart ), will not run on its own while cold, pops sometimes back fires and falls on it's butt while driving. While driving gas pedal has to be feathered to accelerate or else it will die, top speed around 60 maybe 70 kmph where it starts to die out again, if punched to the floor the secondary opens up and will keep it running while it's floored.I played with timing advancing retarding anywhere from 0 to 15 degrees either way, this thing will just not run properly. The timing set in it is a pre- emission 1972 set where cam gear mark and crank gear mark are lined up with each other ( facing toward one another cam down crank up ), new fuel pump ,new distributor. the distributor is a 460 part 80's (electronic with magnetic pick up ) i had ran this kind of distributor with that motor before. Today again pulled the plugs ( carbon black , some have white dots on the porcelain at point of firing ) number 2 plug wet with gas. Put new set of plugs in ( again) runs same. shaky, ( the whole thing was balanced including the flex plate).
fiddled with the carb, floats are ok, nothing else seems to help it run any better.
Anyways it's getting to be a bit frustrating as I'am right out of ideas any help is appreciated.
Thanks.

D.Hearne · Jan 24, 2008

Either the carb wasn't rebuilt correctly (you might have trash in the metering block passages for instance) Or your timing's retarded too much. Should be set at about 10-14* BTDC. Bad idea to go back with a stock cam. You should have at least opted for an "RV" style cam.

69 Rustang · Jan 24, 2008

Do you know anyone with a carb you could borrow to try out? Changing the carb could help isolate the problem. A few years ago I did that with a buddy, helped me to know it was definitely a carb problem before I started to spend money changing parts.

73vertstang · Jan 25, 2008

I've just pulled my 351C 2bbl and was going to have it rebuilt, till I found out it was already 30 over. I had an edelbrock 2V Performer intake and a Holly 750 riding on top. I trashed the block. Your problem may be using the 4V intake with the 2bbl heads, the ports in the heads are not big enough for the amount of fuel mix your trying to send. I found a rebuilt 351C with 4bbl heads, ported and balanced. I have to get a new intake to "match" the heads.

bnickel · Jan 25, 2008

73vertstang said:
I've just pulled my 351C 2bbl and was going to have it rebuilt, till I found out it was already 30 over. I had an edelbrock 2V Performer intake and a Holly 750 riding on top. I trashed the block. Your problem may be using the 4V intake with the 2bbl heads, the ports in the heads are not big enough for the amount of fuel mix your trying to send. I found a rebuilt 351C with 4bbl heads, ported and balanced. I have to get a new intake to "match" the heads.

i believe the performer intake he has is a 2v intake. e'brock makes the performer 351 2v which has 2v ports and a 4v carb pad. he should be fine with the intake he has.

69 Rustang · Jan 25, 2008

73vertstang said:
my 351C 2bbl and was going to have it rebuilt, till I found out it was already 30 over. .... I trashed the block.

Wow, I have rebuilt them up to .060 over. They need sonic checking, but it can be done.

D.Hearne · Jan 26, 2008

bnickel said:
i believe the performer intake he has is a 2v intake. e'brock makes the performer 351 2v which has 2v ports and a 4v carb pad. he should be fine with the intake he has.

Ditto, the Edelbrock Performer 351 comes in two versions-------2 bbl or 4 bbl heads.

70 stang · Jan 26, 2008

cobracobra50 said:
Your problem is that you have 2v heads, which are better than the 4v heads for in town, but you cannot use a 4v intake. You must use a Weiand intake made specifically for the 351C-2v engine/head combo. I have a Pantera and that is the swap I made and what a difference in power. Good luck with the intake switch.
Al

Hi everyone I have a problem with my 351c and would really appreciate any help in figuring this one out.
So the story is, I had just rebuilt a 1972 351C, Bored 30 over, new bearings ( main, rod and cam ) cam is new and is a stock grind, no modifications to valve train aside from putting all fresh valves, seals lifters and so on.
The motor is a 2v, with a 4bl Edelbrock performer intake , the carb is of a replacement kind ( Holley 80457 ) from what i know is 600cfm.
carb was freshened up ( seals, gaskets , rubbers, needles valves and so on )
The problem is that this thing just wont run well, it's missing, no power sluggish
needs to be warmed up for at least 30 minutes before you could even move ( or it dies and gets hard to restart ), will not run on its own while cold, pops sometimes back fires and falls on it's butt while driving. While driving gas pedal has to be feathered to accelerate or else it will die, top speed around 60 maybe 70 kmph where it starts to die out again, if punched to the floor the secondary opens up and will keep it running while it's floored.I played with timing advancing retarding anywhere from 0 to 15 degrees either way, this thing will just not run properly. The timing set in it is a pre- emission 1972 set where cam gear mark and crank gear mark are lined up with each other ( facing toward one another cam down crank up ), new fuel pump ,new distributor. the distributor is a 460 part 80's (electronic with magnetic pick up ) i had ran this kind of distributor with that motor before. Today again pulled the plugs ( carbon black , some have white dots on the porcelain at point of firing ) number 2 plug wet with gas. Put new set of plugs in ( again) runs same. shaky, ( the whole thing was balanced including the flex plate).
fiddled with the carb, floats are ok, nothing else seems to help it run any better.
Anyways it's getting to be a bit frustrating as I'am right out of ideas any help is appreciated.
Thanks.

mikethebike · Jan 28, 2008

I agree with the post advising checking the timing, but have you looked at the plugs to see what color they are? Your problem sounds like a far too lean condition and very possible the timing also just to confound things farther. Did you check your float levels? Nothing like not enough gas in the bowl to feed the engine. Plus it's an easy thing to verify.

73vertstang · Jan 28, 2008

The motor is a 2v, with a 4bl Edelbrock performer intake ,

i believe the performer intake he has is a 2v intake. e'brock makes the performer 351 2v which has 2v ports and a 4v carb pad. he should be fine with the intake he has.

I took his statement to mean he had an Edelbrock Performer 4V intake. When I re-read his statement it's not clear which one he is using, but some of his problems do sound like to much fuel.

Today again pulled the plugs ( carbon black , some have white dots on the porcelain at point of firing ) number 2 plug wet with gas

Only he can say what he has....

Wow, I have rebuilt them up to .060 over. They need sonic checking, but it can be done.

I agree, I could have gone .060 over (would have had to in this motor to true the cyclinders) but the motor would run hot. If I were running the car on the 1/4 mile sure no problem, but I want to use it to run around with the wife on " Nice" Saturday's and Sunday's. When I said I trashed the block, I ment only for this car, I'll save it and maby use it in another project.

69 Rustang · Jan 30, 2008

Just a comment regarding running hot, my .060 over Cleveland does not run hot, in fact, it is the coolest running combo I have had in my '69. It has A/C and the larger radiator, but no problems. Glad to hear you didn't throw it away!

bnickel · Jan 30, 2008

lucky you, i've had 2 standard bore clevies bite the dust with cracked walls.

72 351Cleveland 2v issue Help....

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