Trying to find a piston that will meet my needs. I prefer Wiseco but they do not have a shelf piston that fits my needs. Their -4cc piston puts me below 10:1 and the 5cc option puts me close to 12:1. Looking for another piston recommendation that would be comparable to the Wiseco's.
A 2cc piston with a 30mm c/h would put me about where I am looking to achieve.

If I didnt already have a set of rods I probably would have chosen a cast piston.

81.5mm GSR
E-85/methanol injection
Looking for 11:1 c/r
JRSC 9psi
Autocross car

I am using 212mm for the deck height, there seems to be a little bit of discrepancy on that exact number.
I purchased a kit to CC the head to get an exact number on the head chamber volume, I hope to get time for this tomorrow.

 

Why not custom ones?

 

Cost/availability/complication.

Looks like CP has an offering in the size I need, while I have never used a set I have seen them fail in friends engines that seemed to be a bit premature.

 

gotta be a tune issue, cp's are great slugs

 

Very well could have been, I was not part of any of them just some local first hand experiences.

 

mahle has a piston that's just what you're after with a 1cc dome and 30mm ch

http://cgi.ebay.com/ebaymotors/MAHLE...#ht_1844wt_917

none of these big name pistons will fail if they are setup right. if they do there is another problem and or you were very unlucky and got a bad piston

the nice thing about these mahles is you can run PWC at .0025-.003

 

600105-4 manleys have a 1.2 cc piston according to them its 11.1 on a gsr at 81.5mm..great quality..mines weighted at 315g each...and they come coated like the wisecos...

 

i have no idea what they are smoking unless the comp height was changed. with a stock comp height 1cc is around 10:4-1

they also weigh 45g more than the mahle and have to be setup looser

i can't imagine a reason to run 2618 on a 9psi jackson setup, 4032 is already overkill

 

you can alway use an ls crank and rod combo and your compression will be higher and better torque...

 

I already have a good set of Carrillo GSR rods I would like to use.

I'm starting to question what the 1 point of compression will really help, I have the fuel system set-up for the E85 and have a station within a few miles of my home. The supercharger is flow limited and spinning it faster just makes heat jump up, hence my thoughts on raising compression. The head is ported and has OS intakes flows about 300in/200ex @ 28in

Not looking to light the world on fire, just to make the most efficient set-up I can com up with.

 

a flat piston will make more power than a dome(more efficient cumbustion chamber)...raise your compression by a thinner headgasket and flat valves..you can also mill the head to get 11.1 compression with a flat piston..

 

I have the head already built with flat valves, and already has the GSR combustion chamber. I guess until I get time to cc the head piston selection is a side thought.

I have the cart before the horse.....

 

Foiled by not having a spark plug wrench at home.....

 

What are the chances you'll ever be running pump gas in it? A friend of mine locally had a 12:1 compression 2.4 liter dsm making over 700 HP on E85. If you are set on running E85 all the time I would not be worried about running 12:1 compression myself.

 

I don't think I would have to run premium over e85 but things change and I would hate to be stuck. Then there is always products out there like torco accelerator.)

 

for the boost your running and e85...i would go with the high 11s in compression...there people running 14 to 1 on e85...and boosted set ups 11 to1 on bone stock block and running over 300whp...on 93octane...your lucky you have e85 in your area...the nearest pump is like an hour from me if it wasnt i would run a high compression turbo setup...

 

CC'ed the head today, right at 40cc's with the chamber work, milling and flat valves.

The 5cc Wiseco's puts the c/r at 12.2:1 and at 9 psi that equates to about a 19.7:1 effective c/r.

The -4 cc Wiseco's puts the c/r at about 10:1 and at the same boost level the effective c/r drops to about 16:1

Plan is to run the buddy club spec iii cams and keep the powerband in the sub to low 8k rpm range to not over drive the blower too much. The buddy club cams seem to theoretically fit the supercharger applications quite well if dialed in properly.

 

if you're after 11:1 the +1cc mahle is a perfect fit. at 10:1 the -4 wiseco seems smart since it would be easier to turn the boost up should you ever choose to do so

i still don't see why you want to use a 2618 piston though. 4032 has less expansion and is beyond strong enough for your goals

 

I am only choosing the Wiseco due to my good experiences in the past and they "appera" to have a much nicer "modern" design with the slipper skirts and lightweight design.

I assume the 2618 pistons have a higher silicone content?

 

2618 has less silicon but is stronger because of this , 4032 expands less and can be set up with a tighter piston to wall clearance. both brands are very good. mahle is as far as i know the worlds largest piston maker. they also have top notch thermal coatings which is why they have the tightest PWC of any forged piston i've came across. weight and design is almost identical between the two. wiseco gets used in nascar, mahle in lemans, both brands are top notch, i would focus more on the compression and piston material over the brand

on a cold start up 4032 rattles a little

2618 makes a cummins sound quiet until it gets to temp

the looser the piston in the bore the shorter the life of the engine. you increase bore wear and shorten ring life

cast pistons can go 200K miles or more
4032 if done right can close in on 100-130k before they start burning a lot of oil
i have never seen 2618 used in a mileage motor

the way i've always looked at it on a b series is

300whp or less with limited track use = cast
300whp to...hell who knows? maybe 600whp = 4032

***** out pushed to the limit road or drag racing = 2618

people have made? what, 400-500whp on stock bottom ends and kept it together for awhile. when it did fail it's usually a rod that goes. even the little honda cast pistons can take a serious beating.

 

My last bottom end with Wiseco's went 20k plus with no problems until the valve and piston got cozy....

I never noticed any additional piston slap, then again I was running a pro series skunk camshaft that probably covered any sounds that may have been present.

I will look into the mahle pistons.

Thanks

 

i thought wiseco made 4032 pistons as well as 2618, i know the 1cc mahle will work for your app but wiseco does so much custom crap you may be able to get a 4032 1cc piston from them as well. if you had them before and they didn't rattle cold i almost wonder if you had 4032.

then it just comes down to which costs less. the mahles i posted in that link above from maw products was the best price i found in a quick google search. $440 is defiantly on the lower end for a forged piston/ring set

 

There seems to be some discrepancy on the Mahle some sites list them at 1cc and others -1cc. Either is close enough for my application, I found them through 909 for 410 shipped.

I really like the fact that they come in 81.25 as well.

 

they are positive 1cc, i've had that piston before. mahle also has a top fing notch tech line. give them a call monday to chat on exacts

here's their phone number

http://www.us.mahle.com/na/Power%20Pak%20Pistons

what is wrong online are the pics. this is the actual piston

 

Nice engine stand, ive never thought of doing that.