Running S&S Super Stock heads with stock 80' pistons? : V-Twin Forum: Harley Davidson Forums

ripsass · 09-07-2009, 07:28 PM

Anyone doing it? What are the results?

S&S says to run their pistons with the heads, but the local shop says they run great with the stock pistons too...

My top end only has 15,000 miles on it and I don't want to change them if I don't have to.

The guy telling me this puts together a lot of good running bikes, and sets up all the H-A's bikes too. Theirs haul a**.

I don't mind spending the $ to do it right but don't want to spend where not needed either.

econnor · 09-07-2009, 08:13 PM

Depends on which S&S heads. S&S makes two different heads for stock to 3 5/8" bore Evo engines. What I will call the traditional S&S Super stock head has a enlarged combustion chamber that requires S&S pistons. If you were to run these heads with stock flat top pistons the engine would not run very well because it would not have very much compression. S&S has a newer type of head now for use with a flat top piston, I do not have any experience with them but they look like a good head with a bathtub shaped chamber.

If you already have the heads, you can tell them apart at a glance by the shape of the chamber. The ones for a flat top piston have a small bath tub shape where the other heads have a much larger shape.

ripsass · 09-07-2009, 08:27 PM

Are you talking about the "Performance Replacement" heads from S&S?

I've seen those ones. They say that they are meant to run with stock pistons.

But I'm talking about the regular "Super Stock" heads. I thought the same thing about the compression too. But this shop tells me that they have put these heads on plenty of stock Evo's and they run good...

autotec · 09-09-2009, 10:15 PM

If I remember, this was a few years ago. LOL. The heads will work with the stock pistons, but you will lose compression. The chamber is much bigger in The SS heads. I'm not 100% sure, but this is what I remember when I installed my heads.

I think I went with the S&S 10-1 pistons when I installed the SS heads. Pistons are cheap, might as well install those also.

ripsass · 09-10-2009, 12:04 AM

Ya there's two different chamber sizes from what I'm hearing. If you run the smaller ones the compression doesn't drop much. Or so I'm told.

Pistons are $300, then might as well bore it .010"-.020" while I'm at it too.

Winds up being another $500 bucks...

econnor · 09-12-2009, 10:46 AM

Unless you already have the S&S heads, you could save some cash and end up with the same or more power, without being stuck having to run S&S pistons.

For what you are going to spend on stock S&S heads, have your OEM heads worked over. Many shops are doing head work on evo's that it is almost common to hit 100 hp and tq with an 80" evo. Few people consider S&S super stock heads as the head of choice for 80" evo engines.

ripsass · 09-12-2009, 11:07 AM

There is only one place up here that does geed head work. And it would cost as much as a new set of heads.
I can get a brand new set of S&S's for $700 bucks right now too.

What heads are the "head of choice" for EVO's?

econnor · 09-12-2009, 05:13 PM

Send those heads out to be done. The odds of having a good head porter in any given town in America is slim. Check out some of the sponsors of this site, there are some very good guys on this forum with proven results at a very fair price. A set of good ported heads with flat top pistons is almost always better than the proprietary S&S piston shape and their heads. $700 for heads plus another $250+ for S&S pistons, for $950 you can get allot more.

Check out Kirby at http://www.veetwinperformance.com/servchp.php

Or check our Springer and Bean here: http://www.bigboyzheadporting.com/showthread.php?p=17

Scott at Hillside also does some fine work.

http://www.hillsidecycle.com/

At least check these shops out. These guys can make your heads much better than new and probably for less money than a new set of S&S superstock heads.

ripsass · 09-13-2009, 03:22 PM

Thanks. I'll check them out.

With only 15,000 miles on the engine from original I don't see as need for a total top-end rebuild. I'd re-ring it and give it a hone maybe.

I've had great results with S&S stuff in the past, though not run the heads myself.

Hillside · 09-13-2009, 05:26 PM

Quote:

Originally Posted by ripsass

Anyone doing it? What are the results?

S&S says to run their pistons with the heads, but the local shop says they run great with the stock pistons too...

My top end only has 15,000 miles on it and I don't want to change them if I don't have to.

The guy telling me this puts together a lot of good running bikes, and sets up all the H-A's bikes too. Theirs haul a**.

I don't mind spending the $ to do it right but don't want to spend where not needed either.

Have welded the chambers, to establish the correct compression ratio for the intended use, and blended to a bathtub, with the OE flaltops with superb results.

Scott

blackjackcustms · 10-09-2009, 09:06 PM

S&S super stocks have 2" intakes, and with any kind of cam lift at all, they would crunch stock pistons. I have welded and machined them for 30 deg. pistons, and they flow like monsters. I personally hate the goofy stock chamber, but if you're gonna run it, you'll need pistons in any case, might as well get some compression too.

Hillside · 10-09-2009, 10:14 PM

...............no crunching, if the valve reliefs are addressed in a piston vise in a vertical mill.

Scott

wfolarry · 10-10-2009, 12:20 AM

Quote:

Originally Posted by Hillside

...............no crunching, if the valve reliefs are addressed in a piston vise in a vertical mill.

Scott

That's true.

blackjackcustms · 10-10-2009, 09:43 PM

Yes you can machine your valve reliefs to clear 2" intakes, but you'll still need to address the compression ratio.