Swapping small block exhaust manifolds
I have a non-original motor mid year with a small block and headers. I am taking off the headers and want to replace them with cast manifolds. I have several manifolds but the one marked LH is in rough shape. The others are all RH. The question is can a RH manifold be bolted onto the left side, in other words are the manifolds interchangeable? Is the only difference appearance?
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Re: Swapping small block exhaust manifolds
The exhaust ports and bolt patterns are symmetrical, so yes they will bolt up and function. The configuration of the rest of the manifold will determine how well it fits your application. -
Re: Swapping small block exhaust manifolds
ALLLLLLLLLLLLLLLLLLLLL first generation small block exhaust manifolds and cylinder heads, going all the way back to the first 1955 V8 engine, have the SAME bolt pattern and the SAME exhaust port spacing.
Not that you would want to, but just for example, a 1955 (poor flowing) exhaust manifold can be bolted onto a 1985 cylinder head and function.
Some, but not all, exhaust manifolds have a bracket cast onto one end for mounting a generator or alternator. So that may be a determination which manifold is installed on the left or right side.Comment
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Re: Swapping small block exhaust manifolds
Gents,
But shouldn't the exhaust heat riser (configuration on a right side) also be considered if doing this type of right to left swap?
Most right hand manifolds have a flat outlet flange for the heat riser flat gasket and long stud length. IIRC some don't have the beveled outlet for the exhaust donut. And if one has to change outlet studs it can be a daunting task if badly seized and prone to breakage if not careful.
RichComment
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Re: Swapping small block exhaust manifolds
Am i reading this question wrong? if you bolt the RH manifold to the LH side wont the exhuast be pointing to the front of the engine?Comment
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Re: Swapping small block exhaust manifolds
Bill only on big blocks.Comment
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Re: Swapping small block exhaust manifolds
On Corvettes with a small block ------------------- NOT PASS CARS, NOT NOVAs, NOT CAMAROS, NOT CHEVELLES ------------------ ALLLLLLLLLLLLLLLLLLLLLLLLL exhaust manifolds were the Ram Horn style. The outlets pointed straight down------------------ONLY. NONE of them were angled back.
Also, it is correct that SOME RIGHT side manifolds had a flat surface at the outlet, and they used a flat gasket for the heat riser valve (spacer on FI engines). The heat riser was beveled on one side for the donut. And all right side manifolds had long studs and left manifolds had short studs. As mentioned, after MANY years and MANY miles, the studs were typically seized in the threaded holes. No matter what is done, when trying to unscrew or replace a stud(s), they typically break off. The studs are soft steel and can easily be drilled with progressively larger drill bits until the hole just barely kisses the threads. With care, time and patience, the remaining pieces of the stud can be picked out, a tap run through the threads and a new stud installed -------------------- with copius amounts of anti-seize. I cannot count how many manifolds I've done this to over the past 60+yrs with good success.Comment
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Re: Swapping small block exhaust manifolds
Rich thanks I should have looked under hood firstComment
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