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81 Posts
Discussion Starter · #1 ·

Into the winter i would mount on an M-1 http://procharger.com/marine.shtml with intercooler on one of my engines . I have had the kit for long time but not had time before now to begin with my new projekt.

The kit inkludes: Procharger (belted for an 7.4 l engine so will give some more pressure on my engine) , intercooler , fuel pump and fuel pressure regulator.

It`s an orginal carburatored mercruiser 5,7 260 hp 1982 block.

I would change all:

- Carburator http://www.jegs.com/webapp/wcs/stores/servlet/category_10001_10002_10271_-1_10267

- Engine Bearings
http://www.jegs.com/webapp/wcs/stores/servlet/category_10001_10002_10189_-1_10175 ,

- pistons http://www.jegs.com/webapp/wcs/stores/servlet/category_10001_10002_10219_-1_10175 .

-Engine bearings http://www.jegs.com/webapp/wcs/stores/servlet/category_10001_10002_10189_-1_10175

- piston rings http://www.jegs.com/webapp/wcs/stores/servlet/category_10001_10002_10221_-1_10175

- Maybee Connecting Rods and Crankshafts if nessesary to get more hp.

I have not build an procharger on an carboratored engine earlier so need some info for my prosject.

Do someone have som info for me about parts for my projeckt so i dont blows my engine .
I want must hp out of it for less money.
What type of: - carburator
- Pistons and rings
- rods and bearings
- connections rods and crankshaft if my ordineary cant handle more hp.
- New camshaft if my ordineary does not give enough hp.

thanks oyvind

1,297 Posts
I built a nice procharged combo a few years back pretty cheap.

I went with a freshed 30 over block, stock sbc crank, PM rods and Wiseco dished pistons. I had the 2 bolt block studed and used aregular oil pan. As for as top end I went with the stock 083 heads and 1003 head gaskets and arp bolts. For cam I used a mild comp blower cam and an performer intake to cut on height. Using a p1sc and a 9lbs pulley, we were only able to achieve 7lbs. I suspect the heads didnt allow enough flow. Ended up 431HP and 5121TQ with a 2 core intercooler. This was on a car though. I sold the combo a few years back and it seems to be running perfect still. Its all in the assembly and a good balanced rotating assembly.

440 Posts
"I suspect the heads didnt allow enough flow."

I think you mean the heads DID allow enough flow. If you were supposed to get 9 and you only got 7 that means you're flowing. Pressure is the resistance to flow.

As far as the original post; If you're getting into all what you say you're getting into here's some stout building guidelines:
Clevite or King bearings
Staying around 3-5 pounds of boost stock stuff in general can take it. The only thing I'd really think about changing is the head gaskets other than the carb and a good fuel system.

When you start getting into 7 and above you really want the best.
Forged crank, rods and pistons. Many good manufacturers of each.
You need to set your static compression as to make your effective compression within tolerance. This will depend on your available octane
You can use a 650 holley and have it modified for the blowthrough system. Once modified it will supply all the fuel you'll need.
If you're getting into cams you'll need head work and aftermarket exhaust due to overlap and reversion probability.

I'm not sure what you mean by "belted for a 7.4" Belt length depends on center to center and size of pulleys.
If you're talking about boost, see above octane comment.

If you do a search for ProChargers many build ups have been discussed many times

81 Posts
Discussion Starter · #4 ·
Thanks for good info ;)
When talking about that it was belted for an 7.4l ,i was meaning that it was used on an 7.4 engine earlier and gives around 7psi on this so i think it must give more psi on my engine since its smaller so it does not use so mutch air on same rpm as the 7.4l.
Maybee i`m on thin ice here ;)

What do you do to convert an blower carb to thru - carb blowing?

thanks ø.l
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