Still having performanc e issues after engin replacement
Thread Starter
Intermediate
Joined: Oct 2017
Posts: 27
Likes: 0
Still having performanc e issues after engin replacement
Hello
This is about a c3,1969 ,427 vehicle
I need some help determining What is cousing the problem i am expriencing .Let us begin from the begining.
I replaced the engine with bp 496cu in and currently it has Edelbrock carburator and a msd7582 with its ignitionbox new sarter,batteri and so on
And it has new cilinderheads gasketas because of a badly tuned efi
After replacing the cilinderheads gasket the car had a knocking sound and couldnt deliver all its power
I had the engine dismounted sent it for repaire
the shop had the engin on bench and informed me that the engin spinning as it should and there is nothing wrong with it pulling 460ish hp on 5000 ish rpm
Now i wonder what can be the reason of knocking we heard during staitionary situation . And why the engin could not deliver the power it is supposed to deliver( didnt accelerate as it did befor change of gasket and couldnt do same burnout as if any
can stuffed muffel contribute to it? Or cars electic circuits can be to blame
i just need to add that befor dismounting the engine. Starting upp was not aProblem
I preciate every input i can get
thank you
This is about a c3,1969 ,427 vehicle
I need some help determining What is cousing the problem i am expriencing .Let us begin from the begining.
I replaced the engine with bp 496cu in and currently it has Edelbrock carburator and a msd7582 with its ignitionbox new sarter,batteri and so on
And it has new cilinderheads gasketas because of a badly tuned efi
After replacing the cilinderheads gasket the car had a knocking sound and couldnt deliver all its power
I had the engine dismounted sent it for repaire
the shop had the engin on bench and informed me that the engin spinning as it should and there is nothing wrong with it pulling 460ish hp on 5000 ish rpm
Now i wonder what can be the reason of knocking we heard during staitionary situation . And why the engin could not deliver the power it is supposed to deliver( didnt accelerate as it did befor change of gasket and couldnt do same burnout as if any
can stuffed muffel contribute to it? Or cars electic circuits can be to blame
i just need to add that befor dismounting the engine. Starting upp was not aProblem
I preciate every input i can get
thank you
Last edited by runningengine; Feb 17, 2023 at 01:26 PM.
Thread Starter
Intermediate
Joined: Oct 2017
Posts: 27
Likes: 0
I am using MSD8572 and a MSD 6 box
what i was considering about is the fact. That since i had a blown headcylinder gasket already and since i only have less than an inch in between the actual hood and the aircleaning filter can access to air (cold air)be an aiding issue to the blown gasket .
Can the enginevacume be blamed for the problem(headlamps lifttime is not the same for both lamps) and aslong as we are cooking
can clogged muffler be the bad guy here(i dont know. How old are those things)
what i was considering about is the fact. That since i had a blown headcylinder gasket already and since i only have less than an inch in between the actual hood and the aircleaning filter can access to air (cold air)be an aiding issue to the blown gasket .
Can the enginevacume be blamed for the problem(headlamps lifttime is not the same for both lamps) and aslong as we are cooking
can clogged muffler be the bad guy here(i dont know. How old are those things)
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,212
Likes: 9,352
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
My Guess is you had 2 spark plug wires backwards
Pro
Joined: Jun 2021
Posts: 505
Likes: 230
Here is what I would do first
1. Check the firing order of the wires
2. Make sure the vacuum advance is hooked up to the metered port of the carb
3. Run the engine up to 3000 RPM, set the timing around 30-32 degrees at 3k RPM.
1. Check the firing order of the wires
2. Make sure the vacuum advance is hooked up to the metered port of the carb
3. Run the engine up to 3000 RPM, set the timing around 30-32 degrees at 3k RPM.
Le Mans Master
Joined: Oct 2010
Posts: 6,937
Likes: 848
From: melbourne florida
2023 C3 of the Year Finalist - Modified
Get the timing with a good advance curve in it and throw that Edelbrock carburetor in the recycle bin so someone can make something useful out of it..
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