HarleyTechTalk

Technical Forums => Twin Cam => Topic started by: RTMike on September 09, 2021, 09:36:04 AM

Title: 30 degree pistons
Post by: RTMike on September 09, 2021, 09:36:04 AM
Does anyone make 30 degree pistons for T/C 103 or 107? :fish:
Title: Re: 30 degree pistons
Post by: kd on September 09, 2021, 12:30:30 PM
If none of the HTT builder / vendors can help, you can contact Ron Dickey at Axtel.
Title: Re: 30 degree pistons
Post by: Don D on September 09, 2021, 02:05:28 PM
They are going to help you get what?

If you would like to hear a few counterpoints about the design I suggest asking Randy Torgeson. HYPERFORMANCE. Or his partner Reggie from R&R Cycles. We had this discussion about 12 years ago.
As far as I am concerned I do not like two aspects,  the lock on compression,  can't mill the heads to raise the compression. Lower compression can be accomplished only by cutting the piston, quench distance must be optimal to get any perceived benefits.
so new custom pistons are needed to adjust up, plus they are very heavy biased up top with an already less than supported skirt. The weight of the pistons forces rebalancing in most cases.

The motors I have built and helped guys with ran good but no better than a flat squish design and those lasted longer. I think you can get them from zippers, tman, or axtell.
Title: Re: 30 degree pistons
Post by: Deye76 on September 09, 2021, 03:59:42 PM
I have to agree with Don, after running Axtell 20 deg. A flat top was equal to or better for power and tuned more easily.
Title: Re: 30 degree pistons
Post by: kd on September 09, 2021, 05:08:24 PM
I had an opportunity to use them too.  For all of the reasons mentioned I went with the flat tops. BTW Don, I fixed my previous post reply.  :embarrassed:
Title: Re: 30 degree pistons
Post by: Hillside Motorcycle on September 10, 2021, 03:35:27 AM
A well equipped shop can easily move compression up(or down) with a 30 degree piston, by surfacing, and re-establishing the 30* angle(s), or if need be, start with piston blanks, and machine your own as needed, to include valve reliefs and the 22.5 degree rod scallop.
Simple, straightforward work.
We were using Axtell Angle Top pistons as far back as in the mid-1990's in Evo engines.
CP could whip up a pair in short order.
Title: Re: 30 degree pistons
Post by: Don D on September 10, 2021, 07:00:55 AM
But why? Why bother? What is the cost/benefit today in 2021?
Title: Re: 30 degree pistons
Post by: RTMike on September 10, 2021, 08:04:15 AM
I was just checking options for a set of heads that got screwed up when the piston ring and land broke and hammered out the quench band on the heads.
Title: Re: 30 degree pistons
Post by: jsachs1 on September 10, 2021, 02:35:50 PM
Quote from: RTMike on September 10, 2021, 08:04:15 AM
I was just checking options for a set of heads that got screwed up when the piston ring and land broke and hammered out the quench band on the heads.
You mean like this.
A little welding on the head, along with time on the lathe, head deck, and chamber. Comes out just like new.
[attach=0,msg1394789]
I usually also increase the angle on the heads by 2 degrees over stock.
John
Title: Re: 30 degree pistons
Post by: Hossamania on September 10, 2021, 04:12:49 PM
Quote from: jsachs1 on September 10, 2021, 02:35:50 PM
Quote from: RTMike on September 10, 2021, 08:04:15 AM
I was just checking options for a set of heads that got screwed up when the piston ring and land broke and hammered out the quench band on the heads.
You mean like this.
A little welding on the head, along with time on the lathe, head deck, and chamber. Comes out just like new.
[attach=0,msg1394789]
I usually also increase the angle on the heads by 2 degrees over stock.
John

That had to be one hell of a racket!
Title: Re: 30 degree pistons
Post by: Appowner on September 11, 2021, 04:07:14 AM
Not being a mechanic I was thrown by the 30 degree piston statement.  Never heard that before.  Thanks for expanding my education.

That said I did an online search for "30 degree pistons" and the first hit was the Axtel web site with a picture of said piston.  Holy Crap!  The price of that thing would keep me away. 
Title: Re: 30 degree pistons
Post by: chaos901 on September 11, 2021, 05:39:05 AM
Always interesting to read a discussion from folks that know what they are talking about, even if I can only follow some of it.

Why this site is so good.
Title: Re: 30 degree pistons
Post by: Don D on September 11, 2021, 06:46:45 PM
I just did a remodel on this 2016 head.
2.5 hours, I hate to throw out things. Needs seats done and surfacing to be back in circulation.
Title: Re: 30 degree pistons
Post by: cheech on September 12, 2021, 04:32:38 PM
Quote from: HD Street Performance on September 11, 2021, 06:46:45 PM
I just did a remodel on this 2016 head.
2.5 hours, I hate to throw out things. Needs seats done and surfacing to be back in circulation.
That's what separates you true machinists from the posers.  :up:
BTW, what bolt came out and went through there?
Title: Re: 30 degree pistons
Post by: fatbobber on September 19, 2021, 11:57:07 AM
I had those angle tops in my EVO softail 1340 cc back in the nineties, the bike did 100 rwhp with those pistons and has never let me down on various trips through Europe . Don from Axtell adviced me  those pistons and who am I ,not to believe him , the bike was fast and reliable ;-)
Yes it is quite some job to make those pistons fit perfectly to the heads and adjust the squish accordingly ,but the results are very good ,in my experience better then with the flat top pistons .
I now have those 20 degree angle tops in my 107 cu twin cam fatbob and must say the bike pulls like never before .Along with a T-man 590 and some Zippers stage 3 thundersport heads ( wich i modified to handle the pistons ) and an RB racing modified exhaust...the bike runs like hell,with the thundermax not even quite fine tuned, the bike made 115 rwhp ...i am a satisfied customer ,Ron Dickey's advice is gold as always ;-)
I have a customer with a 88 cu EVO ,running those pistons for 60.000 miles now and they do the job perfectly ;-)