4.3L manifold to riser gasket question

[wncrjb]

Hi,
1994 boat with a 1987 4.3L (SN is missing).

Runs real good but got playing with a temp gun today with it on muffs.

The engine runs at 140 degrees constant.
The risers won't get above 72 degrees but the bottom of the manifolds are running around 160 degrees.

Is it normal for the manifold to run this warm?

I removed the risers to check for blockage and it looked fine in both the risers and manifolds.

I noticed that it had the restrictor gasket on it ( PN 27-41813 )...... only 2 of the 4 slots are open, the other 2 have small "weep" holes.

Would the manifold run cooler if I used the open gasket ( PN 27-818832 ) and let all 4 slots breath or should I stick with the restrictor gasket?

I do NOT have spacers on it.

Just curious what you all think on this one......

Thanks,
wncrjb

 

[Don S]

Re: 4.3L manifold to riser gasket question

1994 boat with a 1987 4.3L (SN is missing).

Since you are showing Mercruiser part numbers, I will ASSUME your 4.3L is a Mercruiser.
Use the gasket for your cooling setup. DO NOT try to use your own logic as to why the restrictors are there. The wrong ones will cause you more problems.
Why don't you just describe your problem instead of trying to find a workaround on your own.

Here is a service bulletin covering the gaskets.
http://www.boatfix.com/merc/Bullet/99/99_10.pdf