|12-06-2004 06:59 PM|
|68NovaSS||The JE pistons for a 5.7 rod I used are part # 131631 and run $669.00 from Summit. If your pistons came from Summit and aren't molested or damaged I'd be willing to bet they'd exchange them.|
|12-06-2004 06:41 PM|
|67 Deuce 4 Me||Ive bulit 2 383's one was a 6 " rod, one was a 5.7. From what I'm reading it sounds like you have 6" rod pistons on a 5.7" rod. I loved my 6'' rod engine. not alot of diffeance in performance.6" set up cost more though.|
|12-06-2004 05:54 PM|
|NXS||Be happy you've got the 6" rod pistons! You are well ahead using them in combination with a blower!(it will be less prone to detonation from timing or fuel problems...and that is what makes your engine self combust with a blower!) Be sure to run some cold plugs also, around an AC 42 or 43 temp range, depending on boost levels.|
|12-06-2004 05:48 PM|
|draven||I bought them all at different times and didn't pay attention to the small note on the jegs website. Stupid me And yes, for faster rev's.. although I guess I shouldn't worry about that too much with the supercharger.|
|12-06-2004 05:45 PM|
I'm pretty sure if you got them from Jegs they told you they were for 6" rods. Why did you want to try to run them on 5.7 rods, rpm?
You surely paid more for a 6" rod piston than a comparable 5.7" right?
|12-06-2004 05:41 PM|
|draven||I bought them from jegs a few months back. I called and they said it would clear fine with 6" rods. Looks awfully damn close to me though|
|12-06-2004 05:36 PM|
I went back a re read your 1st post. I see the machine shop did say to run 6" rods!
Where did your pistons come from?
|12-06-2004 05:07 PM|
So they'll work with a 6" rod then? JE told me they were made for a 6" rod with a 3.750" stroke so they should
Also on another note, what do you guys think of the rest of my combo:
Jegs 220cc 2.10/1.60 Heads 64cc heads,
Crane supercharger cam Adv. Duration: 286°/294°
Gross Lift: .525'/.543''
Mighty Demon 750 w/ mech. secondaries,
Crane Roller lifters,
Jegs 1.5 roller rockers,
Edelbrock super victor manifold,
4.10 Gears, Turbo 350 tranny with 3500 Stall in an '85 GMC 1/2 ton pick up.
What kind of HP/Tq should I see out of this setup with between 8-10 lbs of boost? Could I get away with more with an 8.5:1 C/R? Also thinking of adding a 150 shot of NOS, any problems there?
(Supercharger is the new carbureted vortech btw)
|12-06-2004 04:50 PM|
|NXS||Well those are 6" rod pistons. I wonder why the Machine shop didn't notice the low deck height?|
|12-06-2004 04:42 PM|
170817 Is the part# for them, I'm running into a hell of alot more problems then I expected, lol. So you guys think a 6" Rod won't work?? JE told me it would
Where did you get those pistons and how much were they?
I don't mind going to a 6" Rod but I don't know if I'll have any more problems with that.
|12-06-2004 04:34 PM|
some handy calculators
Here is the location for some handy engine building calculators.
If the pistons are the correct compression height for the stroker crank with 5.7 rods, I don't think you can change to longer rods, unless you change to a shorter crank, too.
|12-06-2004 04:33 PM|
I had the exact same problem with my 383 blower setup, early 2 piece block, using the Eagle 4340 crank and 5.7 rods with a set of JE pistons I bought off eBay. My machinist said he could grind the crank throws a little, the small amount needed for clearance, the only issue would be balancing costs. These pistons were originally custom forged for an LT-1 motor, why they didn't fit I don't really know. I spoke to Eagle's tech and they said they have seen interference problems but never with JE pistons until now, and also recommended grinding the throws. I spoke to JE and without the original order number they couldn't help at all.
I didn't want to cut a new relatively expensive crank, so I sold the pistons and bought a set of JE "shelf" blower pistons with the -31 cc dish and they cleared fine. I didn't want to go with the 6" rods because of the pin interference with the oil ring location.
I didn't lose any $$ so I was lucky in that respect. What part number are your pistons? If you decide to go my route I'll get the part # for the pistons I'm using.
Also, those pistons won't work on a 6" rod anyway, they have a different compression height.
|12-06-2004 04:24 PM|
I called JE and they said to go with the 6" Rod and it should clear fine, so that's what I'll do.
Thanks alot for your advice
|12-06-2004 04:10 PM|
|Tiresmoke7||i would call JE tech support and see what they say. Most pistons are designed to work with a specific stroke and rod length. Call JE and have the JE part # for the pistons you have handy.|
|12-06-2004 03:59 PM|
|draven||Damn, well I'll probably just have them machined then.. How safe is this though? it's hitting right on the arc near the skirt on the bottom of the piston. I'd hate to see these $700 pistons fly to pieces|
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