Logo
FULL SITE MENU

Anyone want to write up a how to to change manifolds and risers

T

tbrodes

Regular Contributor
I want to change out my manifo

I want to change out my manifolds and risers this winter on my 454s. Anyone want to write a step by step on how to do it? I can turn a wrench.
 
"Ted: pretty straight-forward.

"Ted: pretty straight-forward. Drain cooling system, including block and heat exchanger, if FWC. Remove the exhaust hoses as well as the smaller hoses bringing water to the manifolds.
When I did mine, I made a pair of 3/8"-16 studs about 3" long. Remove the end mounting bolts from the manifolds and put the studs in. Remove risers and then remove remaining manifold bolts. Mine were 'stuck' to the heads via the gaskets. A rubber mallet or prybar, if you're careful will loosen them up. They can be quite heavy so I'd get an extra pair of hands. The studs will keep the manifolds from breaking the spark plugs. clean up the gaskets faces with a scraper or safety razor and you are ready to reverse. If it is really tight, you may have to remove one stud, rotate the manifold to vertical, and then pull the other stud.

I swapped out my crusader style manifolds as the risers were ungodly expensive. I used Barr's mercrusier center riser styles as they breathe better and are lighter. I also got (what was new then) the Mercrusier stainless risers.

I kept having the manifold bolts loosen up over time...called Barr and they suggested using NO washers on the bolts...did what they said and they never moved.

I'd also suggest replacing the rubber hoses while things are apart, if needed. If you have access to a pressure tester (with FWC) you can 'inflate' the closed system and watch for soft hoses bulging. Some prefer the squeeze test and replace any with soft spots. Get new hose clamps, too - stainless."
 
"Warning! If the old, rusty m

"Warning! If the old, rusty manifold bolts do not want to come out of the heads, do NOT force them or they will snap off (and then you are screwed!) Give an easily accessible bolt a try, and if it doesn't move STOP and grind the heads off (with an angle grinder, or drill them off).

The manifolds can then be wedged off with wooden wedges. The remaining bolts can then be removed with penetrating oil and heat with a pair of Vice Grips.

Trust me on this!

Jeff"
 
"what makomark said...

My

"what makomark said...

My Crusader 454 had brand new Mercruiser style risers on it when I got her. Just now changing mine out (as it turns out it was not needed) after ten years of service. Granted, I keep my boat in a wet slip up river where the water is mostly fresh but, she still spends a lot of time off shore. The Crusader style are nice but, don't justify the price, IMO."
 
Back
Top