165 HP L6 manifold question

[schwonk1]

Hello All:

I'm a new member and hoping I can get some info regarding the Mercruiser 165 HP L6. Here's a little history on my situation:

I picked up a beautiful '69 Glastron V174 and tilt trailer at auction last year. I got it home and engine was locked tight due to rust, water etc. No big deal. I yanked the engine, disassembled (had to beat the pistons out with a drift punch) and calculated $$ to rebuild...new pistons, rings, rods, mains oil pump, etc. With machine work I figured around $750, as I could do the assembly.

Over the winter here in Ohio, I picked up a complete 165 hp Mercruiser that was rebuilt and sat indoors due to owner losing interest in his boat project. It appears this engine is of 1967-1968 vintage.

My question is:

The original engine has a cast iron manifold with Rochester 2bbl carb, and thermostat housing mounted on front of cyl. head. The manifold has a lot of internal scaling and is possibly cracked. The replacement engine I purchased has an aluminum manifold (Mercruiser P/N 35155) with a Holley carb that is in good condition.

This manifold has a different thermostat housing location if I am seeing things correctly. I can't seem to locate much info on this vintage aluminum manifold.

Does anyone know of any issues with using this manifold when I drop the engine back in the boat??

Any input, pros and cons would be greatly appreciated

Thanks,

schwonk1

 

[windsors03cobra]

Re: 165 HP L6 manifold question

That sounds like a real find ya got there, is the holley a 4 barrel ?

Isn't the thermostat housing on the front of the cylinder head ?
I would use the alum manifold that came with the engine, and keep cooling the intake the way its been cooled for the last 40 years.

 

[HT32BSX115]

Re: 165 HP L6 manifold question

Howdy,


#1, if you just did a complete rebuild on your engine you should not put a possiby cracked or otherwise questionable manifold on it. It will ruin the engine when you least expect it!


There's no real problem with the aluminum manifold except there's a metal (replaceable) plate in them that will corrode thru and allow water to go where it shouldn't.

regardless of which manifold you decide to use you must use the riser/elbow that will match up to your exhaust pipe.

The downside of that aluminum manifold is that if you can find it, it's expensive. Doug Russell for example lists that manifold for $3000+
the good part is that a fresh water aluminum manifold will last a good long time....(I had a 66 Mercruiser 150 (230 cu-in GM L6)) with one and it was original and in good shape)

Needless to say, there's not many buyers for it...Most people with the inline 6 Mercruisers probably go for the newer imported manifolds like GLM etc....like this one from ebasicpower.

Sometimes the imported ones are not all that great though with poor mounting flanges etc......


Good luck,


Rick

 

[schwonk1]

Re: 165 HP L6 manifold question

Thanks a lot for the info... I'm thinking I'll go with the aluminum manifold/Holley setup...The Holley's a two-barrel 4160, which in my humble opinion is a little bit better carb than the Rochester (externally adjustable float level, power valve system etc)

Given the fact that this boat probably sat for a least a couple of years, do you think it's a good idea for me to drop the lower unit and replace the water pump housing and impeller???? I think it would give me peace of mind if nothing else.

Once again, thanks for the help

schwonk1

 

[HT32BSX115]

Re: 165 HP L6 manifold question

I don't think there is a #4160 2 bbl carb...

Go HERE for Holley 4160 info and nomenclature and here: http://www.holley.com/TechService/Library.asp
The 1st link is a PDF so you can just right click on it and save it to your desktop. Open it with Adobe Acrobat Reader


Cheers,


Rick

 

[schwonk1]

Re: 165 HP L6 manifold question

My mistake..it's a 2300 series 2 bbl. Kinda looks like half a four-barrel. Ford stuck some of these carbs on the Maverick and Comet back in the day.

schwonk1

 

[HT32BSX115]

Re: 165 HP L6 manifold question

Holley makes pretty good carbs and they support them well. I have a 4160 that came off my former boat (OMC 460 King Snake)

I took it apart after almost 20 years thinking it was gummed up and found that it was absolutely clean inside! The only thing wrong with it was the gaskets I destroyed taking it apart. I did rebuild it anyway.

I was going to put in on my recently rebuilt Ford 292 Y-Block V-8 in my 55 F-600. I think I'll buy a new "Performer" for it though.... I think the marine 4160 would be far better used on another boat. I even have the OMC spark arrester for it too. I'll probably just put it on ebay.....

Good luck,


Rick

 

[rebars1]

Re: 165 HP L6 manifold question

It is a good idea to replace the impeller whenever you get a new-to-you boat. You may not know how well the previous owner treated it, plus it gives you definite benchmark for your maintainance program. I'd replace the bellows too. If the engine was that rusted up, who knows what shape the inn'ards of the drive might be.