Nitromad

1) A 6" rod with the longer stroke crank gives you a better rod angle @ 90 and 180 degrees of rotation for less piston side loading and more direct "push" on the crank.

2) Hyperutectic pistons are a type of cast piston that has a hi silicon content for greater strength than a standard cast piston.

3)External balanced engines I.E. chevy 400,454,502 use offset weights on balancer and flexplate/flywheel. Internal balanced engines I.E.283,302,327,350,396,and 427 use a neutral balanced balancer and flywheel/flexplate so all the balance weights are built into crank, not bolted on. makes for a smoother running and reving engine and also helps with bearing wear.

sly vette

[URL=Did not like the idea of the piston pins intruding upon the oil ring grooves on the 6" pistons.]
Meaning that the wrist pin is higher in the piston than with a 5.7" rod, I assume??? And if so, is this a legitimet concern???
Later,
Sly

glen242

Eagle 10350375057I internal balance crank, Speed Pro H859CP30 pistons (12 cc dish), SIR 5.7 rods.

Because the block is zero decked, I went with the dish pistons to give me about 10.3 CR.

Using a CC XE274 flat tappet hydraulic.

Runs fine on 89 octane with 36* total mechanical timing.

Flat top pistons would have taken CR to almost 11 or more. Remember my block is zero deck not the stock 0.025 in the hole. It does make a difference on CR.

glen242

It is for me.

C3w4sp

Went through the same thing 2 yrs ago, check my sig. That is where I ended up. I have since installed dynomax ceramic headers. Very satisfied, car has a traction problem but very fast.

I spent a whole lot more that 2 g's to get there, lots of misc stuff that you don't plan for.

I felt this combo gave me the best value, dollars per HP, very upgradeable, better heads and intake are easy swaps, add 1.6 rockers and I can bolt on noticeable power.

jackson

Not all "high-pin" pistons are like this. Some use thinner rings & ring grooves. Those that don't have an "oil ring support rail" that lays in bottom of oil ring groove. I'm not knocking anyone for wondering if this might be a problem ... but either approach is not a problem.

jackson

There's an exception to this; maybe others:
The one-piece rear main seal sbc motors that began about MY1987 are a "hybrid"; in OE form, their front balancer/damper is neutral but their rear flexplate/flywheel has a counterweight ... why??? I have no idea.

sly vette

At this time I assume that the heads that I will be reusing have been shaved, but I don't know how much. I will also be taking off some more to make sure the heads are true, before reassembly. I believe the block has not been decked, 'cause the stampings are clearly visible on the pass side. I do plan on decking the block some so that I know that it is true also. At what point should I be conserned about piston to valve clearance. I know that this is almost an impossible question to answer "cause of the fact that I have yet to select a cam, but any input would be appreciated. Looks like I will be going with Eagle internal balanced crank w/3.75 stroke, Eagle rods at 5.7 length, and Summit fordged aluminum pistons .060 over bore. While I'm at it i might as well ask this question also... what advantages are there to installing con rods and pistons that have floating as opposed to press fit type pins??? Is it only the savings in assembly???
Thanks for all the help so far, I'm learing alot, please keep this info. coming.
Later,
Sly
p.s. Remember that this is a 350c.i.d./145H.P.truck block '74 vintage w/ 4 bolt mains...

sly vette

ttt

sly vette

Another question if you don't mind. In an earlier post, it was mentioned that there may be some clearance problems with the block and oil pan when converting to a stroker. Can anyone shed some light on this issue?
Later,
Sly

sly vette

ttt

sly vette

anyone???
Later,
Sly

glen242

During my search for Hyper pistons for my 383, I never found one for the 6" rod that did not have the pin up in the oil rail.

Which brand(s) are you you speaking of?

Did not want to use an "oil ring support rail".

63mako

I am going through this now. If you use flat tops or dished you shouldn't have any valve clearance problems. You will have to have the block clearanced for a 3.75 stroke but you shouldn't have a problem with the oil pan. Make sure you get stroker profile rods. Otherwise you could have camshaft clearance issues.

Nitromad

Like Eagle "3-D" H-beams or most forged I-beams

mountainmotor

Thats debatable depending on usage , trans type and rear gear .

That set-up does work very well in 355ci engines w/ 4spd and 3.55 gear , 10.08:1 with a cam as small as the older single pattern Comp HE 268 .

BTW , same engine lost 10hp running thru mufflers when they changed to the HE 280 Comp . Heads were stock Fuelies with 1.94's

Anyway ,different strokes for different folks

sly vette

I happened to measure the rods that were in my current eng. and they are 5.7" long, the same size I want to use in the stroker. Can I re-use these rods for my stroker setup???
Later,
Sly

jackson

I'm not aware of a Hyper 383 piston for 6" rod that does not use ORSR ... however, I did not limit my statement to Hyper nor to 383 etc ... (Not all "high-pin" pistons are like this. Some use thinner rings & ring grooves. Those that don't have an "oil ring support rail" that lays in bottom of oil ring groove.) ... not an issue w/ me as I do not have a problem w/ ORSR. There're plenty of Forged 383 pistons for 6" rod that do not use ORSR ... Ross P/N 90766 ... S-P P/N LW2637F ... both use thinner-than-stock ringpaks.

jackson

5.7" Yes ... but by the time you replace rodbolts & have rods resized etc ... you would likely have spent nearly the new budget rods' ebay price. If you really wnat to cheap out on a 383 ... buy a cheap 383 or old 400 crank ... buy a set of used 400 rods (5.565") off ebay (~$20-40/set) and use any plain 350 pistons (~$40-$75/set). That is exactly how the first 383's were assembled many years ago ... things have changed ... and for good reason(s).

sly vette

I know the importance of installing good parts for a good eng. The reason I'm asking these questions is that I know nothing of a stroker motor. Like now for example, I was not aware that the old rod bolts would not work. (clearance again I assume) I also did not know that the rods will have to be resized. I don't know how the rods would have to be re-sized, I imagine that the rod journals would have to be enlarged. Is that correct? I will be the first one to admit that I'm ignorant on alot of the issues involved in putting a stroker together, however that is what makes this site so great, alot of guys that have more knowledge than myself, and are willing to share that info with the rest of us. I thank all of you, and please don't get frusterated with what may seem like obvious questions. Remember, "The only bad question is the one that is not asked".
Later,
Sly