Offshoreonly.com - 454 rebuild with blower... Pistons and clearances.

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Adiabatic efficiency and parasitic losses are two different things of course

Joe - you mentioned earlier the risk with small blower and small intake. I'm about to take the plunge into two 177 blowers. My cam is 227/233, 613in/ 598ex on a 114 Lsa. Oh and brodix aluminum heads right at 9.0:1. Would running these blowers at under 5psi be off concern?

Not trying to hijack, just one question.

Quote:

Originally Posted by ramos45 (Post 4255742)

Replied to your text.

Gotta go visit my nephew the monkey now lol .sounds like tom is going to be happy with his combo .boat should pop on plane nicely even with the big heads and his female passengers will still be able to sprawl out on the engine hatch.

Quote:

Originally Posted by airjunky (Post 4255797)

....and his female passengers will still be able to sprawl out on the engine hatch.

Gotta stick to the priorities!! ;)

Now just gotta be careful with the bravo drives !

Picked up my pistons this evening fellow OSO'er f_inscreennamen. They are in excellent shape and spear to have very little runtime. I'm very please with the fact that I don't have to go the route of boring the cylinders just to get a set of workable pistons. It was looking that way!

Time to buy some springs and valves and retainers, and get to finishing the heads (anyone know of a 1.625 valvespring that would work with a 525efi cam?).

Quote:

Originally Posted by MILD THUNDER (Post 4255737)

Adiabatic efficiency and parasitic losses are two different things of course

Adiabatic efficiency indicates how much of the blowers hp input is turned into heat. So when I say IAT that's what I'm implying yes.

Quote:

Originally Posted by ealesh33 (Post 4254609)

The differences in my build vs your build are as follows

Bore - 4.280
Compression - 8.68:1
Cam isn't done yet but Bob ran some numbers by me that it would be - 654/63? lift, 231-235 duration on a 112LSA
Heads - 265 oval port with CNC chambers

As far as the intake goes I have a rectangular intake as well, not even sure there is an oval port intake for this as I haven't looked. I was told it won't make any noticeable difference in my particular application by 2 sources, but was told what we can do if I am concerned with it.

FWIW, I was told that it was less than ideal to run a rectangular port intake with the "roval" ports on the 265's. I was a bit disappointed with this because I had a very nice Merlin single plane with the brass water passages that I had wanted to run. Ended up with a Dart oval port single plane. Optimal combo with these heads would be an oval port intake that is port matched to the intake port contours. You can get the correct intake gaskets from your Chevy dealer - they are the same ones that they run on their aluminum Edelbrock head engines - think the ZZ502 runs them.

Also, I think there is a GM Performance Products dual plane intake that has the correct port shape, but it is expensive. If you want single plane, an oval port that is port matched is your only option, as far as I know.

Quote:

Originally Posted by Budman II (Post 4257736)

I have A 177 weiand blower, your traditional intakes won't work. I haven't looked very hard for intakes as I was told by my builder that the difference between the 2 would be negligible and I wouldn't notice it.