TRX250R.ORG

Workshop => Engine and Bottom End => Topic started by: croat1 on May 30, 2019, 12:35:41 PM

Title: Cylinder head
Post by: croat1 on May 30, 2019, 12:35:41 PM
Another alternative to the Cool Heads....

https://www.phatheadracing.com/

Joe
Title: Re: Cylinder head
Post by: Hawaiiysr on May 31, 2019, 12:34:31 PM
thats cool. good to know
Title: Re: Cylinder head
Post by: croat1 on November 04, 2024, 08:11:22 PM
Not listed on their website.  Have to call them.

Title: Re: Cylinder head
Post by: broken1 on November 05, 2024, 10:29:38 AM
I don't understand why the aftermarket o-ringed heads are machined with equal size coolant passages all the way around. After all this time you'd think they'd have that figured out.
Title: Re: Cylinder head
Post by: Langbolt on November 06, 2024, 07:38:32 AM
I don't understand why the aftermarket o-ringed heads are machined with equal size coolant passages all the way around. After all this time you'd think they'd have that figured out.

Exactly! The only one I have seen with the coolant passages machined correctly is the Pro-X cast head. ;)

Even MOD-QUAD machines all the passages the same.

https://www.modquad.com/product/250r-cool-head/

:(
Title: Re: Cylinder head
Post by: All250R on November 14, 2024, 06:38:03 PM
I don't understand why the aftermarket o-ringed heads are machined with equal size coolant passages all the way around. After all this time you'd think they'd have that figured out.
I'm on my second prototype for a head that matches the head gasket's coolant ports. I had a local shop working with me, but they ran out of steam with me. It's also based on the old RK deisgn, so it will be easier a little easier to place the o-ring groove than a coolhead  style.
Bryan May has redone the design file, and hopefully will have a head cut for me this month.

It will be made from 6061T6 and will have a slotted head-stay.
I'll post an update when I get the new prototype.
Title: Re: Cylinder head
Post by: croat1 on November 14, 2024, 08:15:18 PM
I don't understand why the aftermarket o-ringed heads are machined with equal size coolant passages all the way around. After all this time you'd think they'd have that figured out.
I'm on my second prototype for a head that matches the head gasket's coolant ports. I had a local shop working with me, but they ran out of steam with me. It's also based on the old RK deisgn, so it will be easier a little easier to place the o-ring groove than a coolhead  style.
Bryan May has redone the design file, and hopefully will have a head cut for me this month.

It will be made from 6061T6 and will have a slotted head-stay.
I'll post an update when I get the new prototype.

Can’t wait to see it!!!

Joe
Title: Re: Cylinder head
Post by: All250R on November 15, 2024, 02:47:52 PM
Thanks Joe. In that case, here are a couple preview images.
Jason
Title: Re: Cylinder head
Post by: Hawaiiysr on November 15, 2024, 05:31:25 PM
Nice!
Title: Re: Cylinder head
Post by: croat1 on November 30, 2024, 08:54:32 PM
Modified OEM head

Title: Re: Cylinder head
Post by: Langbolt on December 01, 2024, 10:02:38 AM
Modified OEM head



Joe, did they weld up the coolant passages and re-machine the new passages ? That is very interesting! :D
Title: Re: Cylinder head
Post by: All250R on February 20, 2025, 12:31:19 PM
I don't understand why the aftermarket o-ringed heads are machined with equal size coolant passages all the way around. After all this time you'd think they'd have that figured out.
I'm on my second prototype for a head that matches the head gasket's coolant ports. I had a local shop working with me, but they ran out of steam with me. It's also based on the old RK deisgn, so it will be easier a little easier to place the o-ring groove than a coolhead  style.
Bryan May has redone the design file, and hopefully will have a head cut for me this month.

It will be made from 6061T6 and will have a slotted head-stay.
I'll post an update when I get the new prototype.

Can’t wait to see it!!!

Joe

I got the second prototype back from Bryan May (Outlaw Racing). He's posted some media pics, but thought I'd post here a few shop-quality photos.
It needs to be tested, and any tweaks made before production runs are made.

The main problems being solved are
  *coolant flow regulation for oring'd heads
  *easier to place the combustion oring than with the well known coolhead design

I'm not sure how best to sell these. I may go to Dave Moore, and Jerry Hall to see if they have a need for a batch order. I'll probably keep a few on  hand for individual customers too. Any thoughts are welcome.
Title: Re: Cylinder head
Post by: croat1 on February 21, 2025, 03:48:36 PM
Jason, very cool!  How were planning to hold the domes when cutting?

I’d reach out to LED, Pete at Hybrid and Bubba Ramsey including the 2 names you mentioned.

I’d be interested in a few.  Any idea on price point?

How
Title: Re: Cylinder head
Post by: All250R on February 24, 2025, 06:14:29 PM
Jason, very cool!  How were planning to hold the domes when cutting?

I’d reach out to LED, Pete at Hybrid and Bubba Ramsey including the 2 names you mentioned.

I’d be interested in a few.  Any idea on price point?

How

Sorry for slow reply Joe.
*I haven't made one yet, but I think they can be cut with a piece threaded into the spark plug hole might be the easiest.

*Thanks for the tip on builders. I'll do this once I have the prototype tested. The slot needs to accomodate non-gasketed heads with no spacer place to CR gaskets with a spacer plate. An ATC/TRX gaskets may be possible (w/spacer plate), and a couple other tests need to pass. We're heading to summer here in Phx (which isn't fun), so I'm working on a plan to test, and get that feedback to Bryan.

*I don't have a firm price yet because I want to bright anodize (clear) the shell so it's finish stays consistent over time for people who maintain a quality ashetic (like me). But I'll try to keep cost with an uncut dome close to what a $240 coolhead would be. I think this would be good for people/builders who want their head spac'd for their own specific engine.

That's the idea so far anyway.