HPE 4mil "bolt in" stroker kit

McDog

McDog

Other Administrator
Staff member
Location
South Florida
@holeshot

What has been your experience with this kit on a cylinder that has a big bore? Several I have discussed this with believe that air flow becomes a problem in a stock cylinder with this much displacement.
 
holeshot

holeshot

HPE products
Location
ca
McDog said:
@holeshot

What has been your experience with this kit on a cylinder that has a big bore? Several I have discussed this with believe that air flow becomes a problem in a stock cylinder with this much displacement.
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The problem with superbore sleeves is they reduce transfer passages. Its not necessarily a flow problem it can be a velocity problem. Giant transfer passages dont equal big power. But high port velocity at low rpm can cause short circuiting or charge dilution. And theres a mach limit on port velocity too. Anyway the HPE 4 mil kit adds crankcase volume which lowers case pumping pressure, my opinion is you wont see a problem on a big bore with the 4 mil kit. Displacement increases BUT the gains come from added leverage at the crank pin and effects of long rod.
So im confident its a strong upgrade for the big bore sleeved cylinders
 
Pantyblaster

Pantyblaster

Location
Graford, Tx
I'm kinda torn between sending my JM735 and having a big bore kit it in or just doing your 4mil stroker kit. Or maybe even have him do the big bore kit and also add your stroker crank. I'm looking for some more bottom end hit out of my rockered blaster. What's your opinion.
 
holeshot

holeshot

HPE products
Location
ca
Pantyblaster said:
I'm kinda torn between sending my JM735 and having a big bore kit it in or just doing your 4mil stroker kit. Or maybe even have him do the big bore kit and also add your stroker crank. I'm looking for some more bottom end hit out of my rockered blaster. What's your opinion.
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hard to comment on the performance gains with his big bore kit, so much depends on port timing and design when it comes to powerband. The 4 mil kit is designed to "hype" the motor from idle to peak peak rpm adding acceleration across the board.
 
Jamo07sj

Jamo07sj

Location
Disco bay, ca
@holeshot turned my 950 Stock stroke into a 999 4 mil. Night and day difference right off the bat. I am not a good tuner but w @Harbor help and some time we squeezed so much more out of it.

The stock stroke setup had a lay down pipe TNT v2

This 4 mil setup I am running two combos, longevity setup bpipe with full size cold fusion, or the NYNJA with kart tank more for flat water, shorter rides.

The 4 mil makes more power with these pipes then the SS did with the lay down, if I tried this with the lay down I would probably have to buy another one lol. I like bpipe / Nynja combo it lets me swap pipes without swapping head pipes / manifolds, battery box, water box etc. 15 min swap.

I have been running it since April or may on 91 pump gas and lightened flywheel , rest electronics are stock including a 61x cdi. (Yes 61 )

First day trying a couple flat water flips did better a lot then expected. Definitely enough power for that. Been ripping it all season without a hiccup, can't even begin to geusse how much gas I've ran through it so far.

Thanks Matt!
 

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holeshot

holeshot

HPE products
Location
ca
Yes i can put together 4 mil bolt in kits for dasa ss. Ive had baseplates made for dasa ss. I dont stock stroker domes for dasa yet but they cut them for me pretty quickly. These kits are NOT just tossing in a 4 mil crank and hoping for the best. Port timing is corrected and you will see gains from idle to peak rpm.
 
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Big Kahuna

Big Kahuna

Administrator
Location
Tuscaloosa, AL
"So we all know ADR stopped manufacturing cranks. I retired with a disability last year and decided to complete my backlog of builds and then slow hpe to nearly a stop so i could enjoy retirement and decide where i want to be business wise rather than being so backlogged i had no choice in sight. I dont depend in income from HPE to survive. So i dont have to sell to survive. That means i can sell parts involved in a build without making a profit and i dont have to charge crazy labor prices either. It also means i can be unbiased when it comes to piston choice or rod length. I dont need to hide knowledge and i dont need to prove my portwork or how my builds run ect. I allowed full access to this thread so that you guys could come on here and tell everyone how your build runs or how the one you rode runs and is it worth the cost. I tried to build you guys a professional package at the best price i could give. "
 
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