Replace Volvo Penta manifolds by mercruiser

Hi all,

i'm from france, so by advance, sorry for my english level !
My boat is a chris-craft crowne 282, powered by a 454 GM OMC with King Cobra on it.

I just pull out the engine because of a leaking oil pan, and i realise i must replace all exhaust manifolds and risers.

Here is my problem : volvo penta / omc 454 parts are very hard to find here in Europe , and
when i find it , it's OEM 1750 ? ($2300) the entire kit ...
Of course , i try to find GLM parts, more affordable, but i canno't find a dealer who can provide the Volvo Omc GM manifolds ...

So my question is :
Can i replace my entire manifold kit by a more affordable Mercruiser Kit and connect it to my VP/OMC 'Y' pipe ?
There is no visual major difference (but the water rail and maybe the height ) between my Volvo Penta manifolds/risers and the 454 Mercruiser ones

I have attached a picture of my engine with his volvo penta equipment


Thanks by advance for your response

Best regards,
Bolbic

Re: Replace Volvo Penta manifolds by mercruiser

Ayuh,.... Welcome Aboard,... In my experience, the diameters of the exhaust piping is Different, usually by 1/2"....

Re: Replace Volvo Penta manifolds by mercruiser

Good luck finding the manifolds for the 454. They are tough to get sometimes in the US at times. Going to get even tougher as time goes on since they aren't used anymore. I am thinking of finding a set and just keeping them for when I need to change them in 5 years.

None of the aftermarket people make that manifold.

Re: Replace Volvo Penta manifolds by mercruiser

bolbic33 said:

So my question is :
Can i replace my entire manifold kit by a more affordable Mercruiser Kit and connect it to my VP/OMC 'Y' pipe ?
There is no visual major difference (but the water rail and maybe the height ) between my Volvo Penta manifolds/risers and the 454 Mercruiser ones

I have attached a picture of my engine with his volvo penta equipment
View attachment 183536

Thanks by advance for your response

Best regards,
Bolbic

Click to expand...

Possibly.............. but you would probably have to fabricate new ELBOWS (those gray cast aluminium tubes on the back of your risers) so the Mercruiser manifolds AND risers would match up to your existing Y-pipe.

Any good welding shop could make elbows for you using Stainless steel tubing. You would just need to match the Mercruiser riser diameter and the OMC Y-pipe diameter.

I would do it if it were mine....


Cheers,

Rick

Re: Replace Volvo Penta manifolds by mercruiser

Thanks all for you precious help !
Instead of Stainless steel tubing, can i use exhaust hoses ?
I'm starting to be borried looking for cheaper manifolds, and i will order the 999$ doug russel packages ... + $730 for shipping to my location.
It's seems expensive but it remain less than what i found here in France.

Euh ... Other question:
May a BARR MARINE POWER manifold would fit ?
LIke this one


I'm asking that because some websites incated this will replace OMC 3852362 .. and that's what i'm looking for !

Last question , i ordered an oil pan on EBay (sierra 18-0614), and i received what i think to be a 18-0615 ( mercruiser one ), can i put this oil pan on my OMC 7.4 knowing it's 1" less height than my original one , and knowing there is only 8mm between my oil pump and the bottom of the oil pan ?

maybe the pic will help


Merci ? tous !

Re: Replace Volvo Penta manifolds by mercruiser

You have a part number for that Barr manifold? Looks different than an OMC manifold.

Re: Replace Volvo Penta manifolds by mercruiser

bolbic33 said:

Thanks all for you precious help !
Instead of Stainless steel tubing, can i use exhaust hoses ?


I'm asking that because some websites incated this will replace OMC 3852362 .. and that's what i'm looking for !

Last question , i ordered an oil pan on EBay (sierra 18-0614), and i received what i think to be a 18-0615 ( mercruiser one ), can i put this oil pan on my OMC 7.4 knowing it's 1" less height than my original one , and knowing there is only 8mm between my oil pump and the bottom of the oil pan ?

maybe the pic will help
View attachment 184070

Merci ? tous !

Click to expand...

It really doesn't matter who's manifolds you use if you also buy their risers. Yes, you could PROBABLY just use hose IF you can bend and match it up to the smaller diameter connection. I would use SS tubing cut/welded to match and use small straight pieces of hose to connect on each end. This way, you get secure leak-proof connections.

If you are replacing the oil pan and the floor of the pan is 1" [25.4mm] higher than the one you removed, AND you only had 8mm of clearance, you're going to have to modify something!!

Re: Replace Volvo Penta manifolds by mercruiser

i mean the one i received ( the wrong ) is 20 mm smaller , and so the pickup is very near the bottom ( 8 mm )
Does Mercruiser oil pump has a shorter pickup than volvo/omc ?
can i use this oil pan anyway without problem ?

Re: Replace Volvo Penta manifolds by mercruiser

Have a look at these on Ebay Item number: 380376802477

CUSTOM BUILT Big Block V8


Mercruiser 454 502 496


Volvo 8.1 8.2

OMC 460 Ford 454 Chev

Indmar 454 496

Crusader 454


Yamaha 454 502


$3,350.00 per set export price - Please note: Australian purchasers add $335.00 GST

One piece stainless steel replaces manifold and 4 inch centre riser in standard height (taller versions available POA).

Also available for Chrysler 440 Ford Powerstroke 7.3 and Chev 6.2/6.5 Diesel Buick 405 445 Oldsmobile 455


Sterndrive or Shaftdrive. unique riser design eliminates water reversion symptoms found with some factory cast iron setups.

High performance one piece unit replaces both manifold and riser. The extractor exhaust system scavenges the exhaust gases to provide minimum 10% - 15% more HP and Torque than standard and customers report fuel savings of up to 30% due to the added efficiency.

Light weight - our set weigh 16kg pair vs 90kg+ for stock setup.

Cooler engine bay due to large water jacket.

Quieter than stock due to less back pressure

No more riser gasket leaks!

Complete with all brackets for ancillaries where necessary (model specific) bolt on and go.

5 year full warranty (the best in the market) and we have them on boats 14 years and still going strong.

Zinc anode to protect against electrolysis

Mounting bolts and gaskets supplied

Polished finish

Every customer who has fitted our manifolds says they will never go back to the old technology again. Ford, Chrysler, GM, Chev, Lexus, Detroit - all look similar from side on, the differences being riser angle/length/diameter/height and manifold angle/spacing in relation to lazercut exhaust flange to allow for taller than standard rocker covers/tight space etc.

info@victorianmarinetechnology.com.au

Re: Replace Volvo Penta manifolds by mercruiser

For that price, I would call Hi-Tek marine out of Australia, or Custom Marine up in Wisconsin USA and have a custom set made.