getrdunn

iTrader: (7)

I just tought about putting together some SC budget builds. I was wondering if anyone has used the old oval port heads with these 177's. I have two perfectly good sets of GM 049's. Not looking for max performance by any means however would like to use what I have otherwise see if I can trade off my heads for some rec ports. My biggest fear would be building up to much heat.

Thanks
John

jeff1000man

I re did a jet boat for a guy using the ovals. It was a square port intake.

The hole shot was unbeleivable. This was the way the engine showed up, I just freshend it up, and got it to run right.

It really had a lot of punch. I never dynoed it or anything like that for comparison, but if it is a small displacement engine like a 525SC, then maybe it would work.

getrdunn

iTrader: (7)

Thanks Jeff,
ya it's just for 454's. When you said the square port intake are you refering to the rec port one that's on the 525 SC's. On an NA engine I have tested this before having Rec port intake and oval port heads. It sounds nuts but in certain applications I think it helps anotamize better. Valako and I actually messed around with the on some heads he raised the floors in many years ago but not on a blower engine.

Did you experience any problems with valves or piston value with the said set up?

Thanks again,
John

Griff

It would probably work ok. I do think rect ports would be better. The ovals will probably cause higher boost pressures due to decreased flow. It really all depends on what you have to work with. You could build some decent NA engines with the ovals and still get around 500hp. Depending on the ovals that you have and if they need to be gone through, you may just be better off selling them and then buying some rect ports.
Do you already have the 177's???? If not, I would go with 250 blowers. Not much more $$ and they are not as maxed out on a 454 and enough for a 502 as well.

getrdunn

iTrader: (7)

I already have like brand new Merc/177's. I kind of had the same thought with the oval ports allowing for a little more boost. I just hate to see these 177's sit on the shelf and could do my builds relatively inexpensive. My only concern was using the rec port intakes.

thanks,
John

Payton

Just make sure you have upgraded the valve seat correctly. The reason I say this is a letter in the tech section of Powerboat mag had trouble with the valve seats falling out in that application.

WR-1

I used to run a b&m 174,and I remember in the service/installation manual it said you could put the supercharger right on a base 330hp 454,with the proper adjustments,I don't know if they even offered an oval port intake.I will try and find that manual and see what it says,but I believe you will be fine.

getrdunn

iTrader: (7)

I was wondering if they offered a oval port intake as well. I could always open the intake ports up near the gasket area but would rather not for a couple of reasons. I was almost thinking of cams with a little more duration than that of the 420 hp cams so I don't have to much boost with stock pullies. I plan on running flat tops with 119 cc chambers. I would think the torque would be awesome with this set up.