[C2] Exhaust manifold size
06-24-2018, 04:22 PM
#1
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Exhaust manifold size
Just in case the exaust manifolds were replaced by a prior owner how can I tell what size they are other then disconnecting the exhaust. It’s a 65 327 300 hp
06-24-2018, 04:28 PM
#2
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2015 C2 of Year Finalist
There should be part numbers cast into the manifolds Find the numbers and look it up or post it up and that will tell you for sure
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Jriver (06-24-2018)
06-24-2018, 04:37 PM
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Just in case the exaust manifolds were replaced by a prior owner how can I tell what size they are other then disconnecting the exhaust. It’s a 65 327 300 hp
Get your wife to give you her paper tape measure. Wrap it around the pipe, just below the manifold and take a measurement. Divide that number by Pi r squared. The answer is your answer.
Last edited by MikeM; 06-24-2018 at 04:42 PM.
06-24-2018, 04:56 PM
#5
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06-24-2018, 05:09 PM
#6
Race Director
Pic above shows a correct exhaust manifold for a 1965 327/300 HP manual trans car. No air conditioning. GM# 3846563.
The other side should be GM# 3797902
Should be 2-1/2 inch exhaust pipes right off the ex manifolds.
Larry
The other side should be GM# 3797902
Should be 2-1/2 inch exhaust pipes right off the ex manifolds.
Larry
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Jriver (06-24-2018)
06-24-2018, 05:14 PM
#7
Drifting
06-24-2018, 05:30 PM
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1964 all 250hp engines (regardless of trans type) and 300 hp auto trans engines used 2 inch manifolds.
300 hp manual trans, and all other optional engines used 2 1/2 inch manifold.
I believe that 1965 was the same arrrangement.
Which actual manifold depended on what options were on the car.
300 hp manual trans, and all other optional engines used 2 1/2 inch manifold.
I believe that 1965 was the same arrrangement.
Which actual manifold depended on what options were on the car.
Last edited by emccomas; 06-24-2018 at 05:31 PM.
06-24-2018, 05:37 PM
#9
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The left manifold looks like s 563, so I am guessing that your car has a manual trans.
The right side manifold should be a 902 (last three digits).
They are 2 1/2 inch manifolds.
The right side manifold should be a 902 (last three digits).
They are 2 1/2 inch manifolds.
06-24-2018, 05:58 PM
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With all due respect to your post, I've removed a lot of manifolds and never seen a bolt missing because there were no french locks in place. As a matter of fact, once I've removed them, I've had engine go for many years with NONE in place and the bolts didn't even loosen. Just a PIA to deal with in my opinion.
I always preferred to use AN washers under those bolts with not problem.
I always preferred to use AN washers under those bolts with not problem.
Last edited by MikeM; 06-24-2018 at 06:22 PM.
06-24-2018, 06:50 PM
#12
06-24-2018, 07:42 PM
#13
Drifting
With all due respect to your post, I've removed a lot of manifolds and never seen a bolt missing because there were no french locks in place. As a matter of fact, once I've removed them, I've had engine go for many years with NONE in place and the bolts didn't even loosen. Just a PIA to deal with in my opinion.
I always preferred to use AN washers under those bolts with not problem.
I always preferred to use AN washers under those bolts with not problem.
06-24-2018, 08:17 PM
#15
Instructor
Thread Starter
[QUOTE=62cruiseer;1597472959]Ugly question. Is it missing or snapped off in the head? 
Dont know I didn’t want to deal with tonight
Dont know I didn’t want to deal with tonight