Stroker Pistons for Shovelheads, who makes 'em?

[lairdog]

I have a 93" pan motor(S&S cases) with STD heads, Which I am pretty sure use shovelhead pistons.that I need pistons for & would like to know if
there are other options besides S&S for some quality pistons.
I found a company called CP, But there's only go up to 88" strokers.
Also, I do not want high compression, preferably 8.5:1 S&S pistons start
at 9.0:1 for their stroker pistons.
I called wiesco pistons & they do not have what I am looking for either.

the reason I want to keep the compression below 9.0 on this motor
is that It has a kick only trans, & do not want to hassle putting a starter
on the bike.

[govmule84]

Forgive me for not directly answering your question, but would a set of compression releases improve your life?

Jesse also got wind of this thread and says Keith Black makes what you are looking for in both a cast and forged version.

[lairdog]

Mule, I already have C. releases & they don't work worth a shit as
far as assisting starting. I use them for prime kicks though!
the current pistons I have are 9.5:1 & It sucks trying to start the bitch.
the only thing that kicks harder than this stroker motor is an old
recording of allen Woody at the roxy theater in Georgia in the late 90's.

It is such a bitch to kick, that I already snapped off the shaft on the
kick pedal, & then recently the woodruff key on the kicker gear sheared
in half! a buddy of mine almost dumped the bike several times trying to
kick it to life. then fucked his ankle up. & the problem is definitely compression, since it kicks super
easy when the plugs are pulled

[govmule84]

That Allen Woody sure did kick hard. Call Keith Black, it sounds like

[magnum45pete]

a good machinest might be able to remove some of the piston dome to lower compression.... I did this to lower the compression in my 45 magnum and has worked great for the last 4 1/2 years.... the 900 sportster piston crown had more than enough meat on them for this to be done safely.....measure the crown thickness on your pistons and see if it's doable on yours...

[lairdog]

mule, i'll check KB again. DIDn't have any luck in a previous web search.

mag45.... yeah, I thought about machining the domes, but does it need
to be a radius or curvature on the dome. or can the dome be machined flat?
I could very easily use my Bridgeport to take off some material off the domes,
but it will be flat, since I do not have CNC.

Seems to me that combustion would be hindered if the tops were just machined flat.

[ralphiejantz]

Give JE Pistons a call they can custom make you whatever you want and so can Diamond.

at 9.5 to 1 though you should not be having any trouble kicking it through.

My old 93" shovelhead was 10.5 to 1 and kicked over just fine.

What kind of cam specs are you running. The specs on the cam will also affect kicking compression so you might have something in there that is not ideal for your setup.
Plus its a hell of a lot easier and cheaper to swap a cam out with the right specs vs taking the entire top end of the motor off to swap pistons if you don't need to

[govmule84]

Jesse says the KB website is useless. He told me to have you call Marco there. 1 800 648 7970, x191.

I also agree with Carmine; JE will make fucking anything... they made me a set of pistons for a Jap-only Honda motor that was eating nitrous. If you have the money, they have the time.

[lairdog]

thanks guys.

This motor is new, & supposedly has "9.5:1" Compression. I am thinking that
the builder (accurate engr.) possibly screwed up & did something like 11:0:1
It just has major resistance.

The Cam is definitely Not a mild cam, It is a Lieneweber L51 which I believe has
a lift somewhere around .520 but with the spark plugs removed, there is very
little resistance when kicking, which makes me believe that compression is the
factor here.

[little d]

Lairdog,
have you considered stroker plates? Sounds like they did ya a favor and bumped the #'s up a little for ya but kicking that......

[twistedtee]

Can't kick 9:1?
Jerry
Rhode Island

[gasketscraper]

I think the overlap on the cam is the issue. Its causing too much static compression when kicking. I mean breaking a shaft on the kicker is pretty extreme. Have you put a compression gauge on it while kicking it over? Maybe they did put Higher C.R. pistons in than stated.

[JasonMcElroy]

I'm with you, GS. It's not only about the compression. The cam overlap makes a big difference.

Learned this the hard way back when I built my 93" motor. Now have it at a happy medium as it's a kick-only bike.

Jason

[BigDawg]

Originally Posted by ralphiejantz

Give JE Pistons a call they can custom make you whatever you want and so can Diamond.

at 9.5 to 1 though you should not be having any trouble kicking it through.

My old 93" shovelhead was 10.5 to 1 and kicked over just fine.

What kind of cam specs are you running. The specs on the cam will also affect kicking compression so you might have something in there that is not ideal for your setup.
Plus its a hell of a lot easier and cheaper to swap a cam out with the right specs vs taking the entire top end of the motor off to swap pistons if you don't need to

^This. I run 9.78:1 forged S&S (Wiseco) pistons in my 100ci and it's a cupcake for me to start. I run an Andrews B though. It may not give me the most performance possible out of that motor, but it's easy to start and it runs good.

[Dave B]

Don't do anything piston wise. Run a cam with a late intake closing time. This way the cam bleeds off some of the compression. Trouble is alot of those cams don't pull hard until 4000 rpm. { Overlap is the period where both the intake and exhaust are open at the end of the exhaust stroke.] Later intake closing time in a cam is what you want.