What big bore kit is this

[LONG-ROD]

I have not broke this motor down yet, but can any one tell me what it is.

[CorvetteZ06]

def. a pro-X cylinder, besides that, really couldnt tell ya more just from that pic.

[C-LEIGH RACING]

The cylinder is a new model Pro-x because it has the renforceing web on the side of the reed chamber.
The head is an old model with a non replacable dome, dome & squish is cut into the head casting.
Old model first cast Pro-x cylinders didnt have the renforceing web & + the area where the reed cage bolts up was shorter & caused problems in mounting the carb to the air filter boot.
The first cast Pro-x cylinders were cast by CP Industrys.

Something else I noticed, the cases are different year models, right side is a 85/86/87 & left is 88/89.
Neil

[norcalduner]

Originally posted by C-LEIGH RACING
The cylinder is a new model Pro-x because it has the renforceing web on the side of the reed chamber.
The head is an old model with a non replacable dome, dome & squish is cut into the head casting.
Old model first cast Pro-x cylinders didnt have the renforceing web & + the area where the reed cage bolts up was shorter & caused problems in mounting the carb to the air filter boot.
The first cast Pro-x cylinder were cast by CP Industrys.

I again have learned something new in this forum.
Thanks for your insight Neil.

[ib2strokin]

Neil, how can you tell the differences in the cases? Is it ok to mix match cases, or is there a benefit to certain year cases?

[CorvetteZ06]

you can tell that the cases are different years by the open space where the front motor mouunt bolt goes through. 85-87 has a smaller opening, while the 88-89 has a bigger opening. you can see it in the pic.

[C-LEIGH RACING]

Originally posted by ib2strokin
Neil, how can you tell the differences in the cases? Is it ok to mix match cases, or is there a benefit to certain year cases?

Old 85/86 models are thicker on the outside around the crankshaft area & are better to use when building a stroker engine. Reason, when the cases need trenching to clear the rod, theres more metal left for strenght.
Another +, when buying new cases, the old 85/86 come with all new bearings & seals.
The 88/89 new cases only have the thin shift drum bearing & the two clutch rod/arm bearings.
Neil

[LONG-ROD]

Thaks for poining this out, I don't underst6and the benifit of the two diffrent cases together. Do you think at glance this motor is stroked, is there anyway of telling just what this motor has done without tearing it down?

[ib2strokin]

Originally posted by C-LEIGH RACING
Old 85/86 models are thicker on the outside around the crankshaft area & are better to use when building a stroker engine. Reason, when the cases need trenching to clear the rod, theres more metal left for strenght.
Another +, when buying new cases, the old 85/86 come with all new bearings & seals.
The 88/89 new cases only have the thin shift drum bearing & the two clutch rod/arm bearings.
Neil
cool, well i guess that the guys at C&C in sikeston knew what they were doin when they built the motor i have now. i couldnt figure out why they used 85 atc250r cases when they built my +2mm stroker, using an 88 jug, and an 86 piston w/ spacer plate. he built the motor for his daughter to race and it came with the quad that i bought from a buddy. im guessing that the reason for the +2mm stroker over the +4mm would be having more overbores and still stay under the 265cc limit, does this sound right or am i totally wrong?

[C-LEIGH RACING]

Originally posted by ib2strokin
cool, well i guess that the guys at C&C in sikeston knew what they were doin when they built the motor i have now. i couldnt figure out why they used 85 atc250r cases when they built my +2mm stroker, using an 88 jug, and an 86 piston w/ spacer plate. he built the motor for his daughter to race and it came with the quad that i bought from a buddy. im guessing that the reason for the +2mm stroker over the +4mm would be having more overbores and still stay under the 265cc limit, does this sound right or am i totally wrong?

With a 74mm stroker crank you can bore in up to a 67.50mm piston & be under the 265cc limit, 264.8cc.
Neil

[ib2strokin]

Who makes a 2mm stroker crank for the R's or does it have to be custom made? I've looked and looked and all I can find is 4mm and I think 3mm, but no 2mm

[kiesta00]

A 4mm stroke really isn't worth the extra setup headache...and they wear pistons out quicker. If I could build my motor again I'd build a bulletproof 72mm crank for the price of a hotrods 76mm.

[ib2strokin]

yea ill prolly just stick with my 2mm stroker, but im not sure who i could get a replacement one from if this one ever craps out?

[LONG-ROD]

Does'nt hot rods make crakes to your specs?

[86 Quad R]

i'm in the process of checking THIS (http://www.mrcrankshaft.com/) guy out.

[LONG-ROD]

Remember you get what you pay for , and a well know company will stand behind there products and work.

[C-LEIGH RACING]

Originally posted by 86 Quad R
i'm in the process of checking THIS (http://www.mrcrankshaft.com/) guy out.

You had any contact with this guy yet.
Rod price looks low, wonder what rod kit hes useing.
Neil

[86 Quad R]

ya have a pm neil.

[86 Quad R]

Originally posted by LONG-ROD
Remember you get what you pay for , and a well know company will stand behind there products and work.

in most cases i suppose they do but, sadly i'm reading more en more where they arent/wont stand behind their stuff.

big/major companies were small people at one time. :blah: