It looks like my other post got weird, maybe my new name or in the new upgrade. I am redoing a 390, Edel package, heads, Performer rpm cam, manifold, and carb 750 cfm. I just got my L2291F30 pistons and they came without Data sheet. Does anybody know what the cc's are on the valve reliefs? I tried cc'ing with alcohol, food coloring, plastic plate and some syringes, and I get very close to 9 cc on the 4 I have checked. Not sure if my procedure is correct, as 9 cc's seem a bit high. What cylinder to piston clearance have you guys run with this piston? Also what rings? Plasma moly sound like the way to go, but is that just advertising hype? Also next on the list is bearings, what's hot and what's not. I hope to end up with zero deck, with offset grinding, but I am still discussing with a couple of machine shops. By the way I just got the headers, from Stan's and they are pretty good looking, ports look like they match the Edelbrock heads pretty well. I'll have to grind to match a very small amount. The gaskets, they furnished on the other hand are a different story, way too small, bolt pattern is okay, but port height is short by about 1/4", a small hurt, and will go away quick. I would like to hear what you guys have to say about the aluminum heads as far as gasket recommendations. I have been reading about some places that will make a custom thickness gasket, and I wonder why all the aftermarket gaskets are .041" Was this standard? Would going to .031" be a bad thing for any reason other than CR? It seems to me with my plan, .037" quench/squish distance, the aluminum heads, and premium gas 10.5 or 11 : 1 CR should be okay. Why are head gaskets made so much larger than bores, is it one size fits many overbores, or is it a necassary dimension for keeping the gasket surface away from the combustion temperatures. Any thoughts?
As always, thanx for any responses.
75 F250 4X4 390, C6, 4.10 rear, and 4.09 front, still trying to figure out what the front and rear axles are......

Tom
Tomridge, AKA TTommaney2

 

I almost bought the Stans. I went with the Sandersons instead. Just got them and am very satisfied. No gasket either, has O-ring.

Broom

 

Not sure about the gaskets, so I'd be interested in the answer, too. I bought the Fel-Pro performance head gaskets, which I assume you bought. They're .041" compressed. I seem to recall that some of the cheaper gaskets were in the .02-.03" range, though I could be mistaken. I wanted a lower CR, so the thicker gasket didn't bother me. In terms of bore, I think the same gasket was used for pretty all FE's (except maybe the 427), so it had to fit the 4.00, 4.05 and 4.13" bores.

 

Yes, I've got the Fel=Pro gaskets, but would like to go thinner, and reduce the bore of the gasket. I found a guy that will make them but hasn't quoted a price yet, so I'll let you know. Any thoughts on the 9 cc valve reliefs on the L2291's?

 

Can't help you there. I'm using dished Sterling 390 truck pistons in the 410 I'm building, as I wanted to keep the CR below 10:1 with my 69 cc C8AE-H heads. My pistons measure 17 cc with the dish and valve reliefs. I would have guessed 5 cc for valve reliefs on standard 390 pistons, but 9 cc sounds reasonable.

 

Try this website for data on your pistons:
http://www.gessford.com/cobraparts/fblocks.htm

It does say on the description that there is a -10cc dish. On the data sheet it lists a CR of 9.62 with a 71cc head volumn, .030" overbore, and a deck clearance of .015". To get to 10:1 the head volumn has to shrink to 67.1cc or the deck on the block needs to come down. I'm running those pistons on my 390 with a deck clearance of .007" and Edlebrock heads.

I like the plasma rings and used Speedpro file fit set part# R-9220-35 and set the top gap to .016".

When installing the intake, make sure there is clearance for the pushrods and the manifold bolts line up. I had to do a fair amount of grinding on my RPM manifold. I've heard that this is not uncommon with this manifold.

The gasket recommended by Edelbrock for those heads was a Felpro 1020 which has a compressed volumn of 9.1cc. The reason for the larger size is that the gasket is also used on a 427 with a standard bore of 4.23".

If you are using a cam with a lot of lift & duration, you'll need HD rocker shafts with end supports. Without these, the shaft may break, and this would be a bad thing....

I would call Stans and ask them about the differences in ports. The gasket is for truck heads and you are using edelbrock. That is the reason for the 1/4" difference on the port height. I didn't know about that when I installed my Hooker Competition headers. Opps!

 

Sunny, thanks for the feedback. Did the data sheet on the pistons recommend piston to cylinder clearance? Did you machine the deck to get the .007"? Is that maybe why you had to grind on the manifold? I was not too worried about the gasket for the Stan's as the header openings matched the heads pretty close, a very small touch with the grinder can take care of it. 10cc on the piston valve relief's hmmm guess my cc'ing method was pretty close. As far as rocker shafts, I've got the Harland Sharpe set up, (roller tips, and hardened shafts) I have ordered stands and end supports from Rocker arm Specialist, hope to have them next week. I am still weighing the cost vs benefit of offset grinding the crank to get zero deck vs having the deck machined. A thinner gasket would accomplish the quench distance I am after (.035-.040), but no luck so far on going that route for a reasonable price. Has anyone used the 2292 TRW's, with the Edel performer cam?
Tom

 

If you go to the web site you can print out the FM catolog pages which has a bunch of info on them. They list a skirt clearance of .0020". I had my block decked to make sure it was flat, parallel to the crank, and 90 degrees bank to bank. Need to have you block checked to see if it is parallel with the crank. If it is not parallel, than you cannot offset grind it to get zero deck height. I'm running a Crane cam with .501/.533 lift with no problems.

The reason I had to grind the manifold was because the bolt holes were not lining up and the manifold was shifted over to the drivers side. Also some of the pushrods were a little too close for comfort.

Reggie