I'll try this again, exhaust manifolds

TollyWally

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Dec 26, 2007
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19
I'm going to give this another shot. It is time for spring refitting and I would like to replace my 4" risers. I have a Volvo marinized BBC 7.4 freshwater cooled motor. While the Volvo engineering is quite decent the Swedes are just too damn proud of thier spare parts. It is time to replace my risers and I would like to swap out the whole system, manifolds, risers etc.

I am leaning towards Crusader parts but am interested in others opinions regarding these and the other various aftermarket suppliers, Barr, Osco, Sierra, etc. I am interested in a simple robust design, easy to service with relatively inexpensive consumables. If I could get a place to install an o2 sensor for carb calibration I would be quite pleased. :)
 

TollyWally

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Dec 26, 2007
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Re: I'll try this again, exhaust manifolds

Don,
I thought the topic line was clear. I reposted because I did not receive any input so I was trying again before giving up. You and I had several posts regarding serial numbers etc. but no actual discussions regarding hardware.

I apologize if I have violated etiquette here, it is time to order some parts and get this done before the weather turns.

Volvo BBC 7.4
Holley Carb
Freshwater cooled
Straight shaft Velvet drive
4" exhaust necking down to 3" mufflers
 

Don S

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Re: I'll try this again, exhaust manifolds

All you need to do is bump your original post to the top by repling to it. Then all the previous information will be there.
None of the 740 exhaust systems are available aftermarket.
 

TollyWally

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Messages
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Re: I'll try this again, exhaust manifolds

Thank you for the reply Don,

I understand that there is very little support for the Volvo BBC, even from Volvo. Last time I swapped risers it was quite difficult to source factory parts.

That is why I indicated in my post I am interested in swapping out manifolds and risers to a system that is better supported. I am willing to go to another brand of OE that is better supported or to a complete aftermarket system.

"None of the 740 exhaust systems are available aftermarket."

Does this mean that there is no other fresh water cooled exhaust manifold system for the BBC that is supported on the aftermarket? If so, I am quite misinformed.

If this is the case I am interested in other's experiences and opinions regarding other suitable OE systems. If this is not the case and indeed there are other OE systems that enjoy better support including the aftermarket, I am interested in others experiences between specific brands.

Thank You
 

erikgreen

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Jan 8, 2007
Messages
3,105
Re: I'll try this again, exhaust manifolds

I think you already have an answer, but you just don't like it. If there was something out there, Don would know. I'm surprised he hasn't written any books on marine engines.

If you were informed that there are after market fresh water cooling systems for your engine from someone, ask them which ones they're talking about. It sounds like you're pretty convinced that they exist, so ask the person who convinced you where they get their information.

If it's a standard engine block you can always convert something from another mfgr., but you will end up with an unsupported configuration... that's just gonna be the way it is unless you replace enough of your drive system to get supported again.

Have you looked at any specific systems from crusader? You won't find a "replacement system for a volvo 740" in a catalog but you will find something like "big block chevy manifolds" to go with "big block chevy fresh water cooling" and "big block chevy circulating pump".

You might want to clarify your question - post some specific examples of manifold sets you're considering and see what people think of them. A lot of folks here won't have a high opinion of anything but the OEM manifolds since companies like GLM marine are hit or miss on quality.

Erik
 

f_inscreenname

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Aug 23, 2001
Messages
2,591
Re: I'll try this again, exhaust manifolds

There is a crap load of stuff out there for the 454. There is about nothing on my motor that came out of the factory. Post a picture of you set up. Better yet, change it all over to "MerCruiser" and change a little plumbing and your set.
Myself, I would go for the GLM's on eBay. Really like the idea of the exhaust runners built in the manifolds.
 

Don S

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Re: I'll try this again, exhaust manifolds

Better yet, change it all over to "MerCruiser" and change a little plumbing and your set.

Obviously, you have never seen the convoluted one of a kind, never imitated or copied, exhaust manifold, riser, massive amount of freshwater cooling system riigid copper tubing with special ends, special thermostat housings unlike anything else, absolutely one of a kind, and Extreamly expensive exhaust and cooling system. on the 740A and B series VP engines.

It is almost cheaper to install a completely new engine package as try to cobble together something to work in place of the OEM parts. Every bracket for coolers, hoses, thermostat housings, heat exchangers, manifolds, risers, you name it, get's changed to make it work. IF you are lucky.
 

Don S

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Re: I'll try this again, exhaust manifolds

OMG :eek:

Why did they do all that? :confused:
My bad.:(


LOL, Yea, what you did putting that Merc 454 to the 270 was childs play and cheap, compared to converting a 740 exhaust/cooling system.
 

TollyWally

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Dec 26, 2007
Messages
19
Re: I'll try this again, exhaust manifolds

Thanks to everyone for the input.

"It is almost cheaper to install a completely new engine package as try to cobble together something to work in place of the OEM parts."

Thanks for the heads up.

I appreciate Swedish engineering, it is good,it's just not as good as they think it is!
I remember an old fisherman pulling out a perfectly running Volvo that needed a starter. He replaced it with a 3208 Cat and dumped the Volvo off the end of the dock. He said he'd be damned if he'd pay that kind of money for a starter.
 
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