turbo head work




202mphbusa

Registered
I have a HMP Rick Stetson head that is Stock seat 1mm O/S valve, that is in need of freshen
I was running the head when I was all motor. then for a little while on my first turbo setup
I pulled it off cause it seemed like it was killing power down low
I am looking to send it for refresh 1/2 studs and possible change back to OEM size valve
So my question is
Turbo head work who is out there ready........go
 

c10

Registered
I have a HMP Rick Stetson head that is Stock seat 1mm O/S valve, that is in need of freshen
I was running the head when I was all motor. then for a little while on my first turbo setup
I pulled it off cause it seemed like it was killing power down low
I am looking to send it for refresh 1/2 studs and possible change back to OEM size valve
So my question is
Turbo head work who is out there ready........go
Harold is a friend of mine here in Richmond Texas . Harolds automotive machine shop .
Don't let that scare you . He does many Busa's and race bikes from mild to wild .
He also rides ;) , and use to race himself . Hes made a few parts for my bike with specs I gave him .
281-342-4514 Tell him Little Bryan with the Tour Busa sent you ;)
 

202mphbusa

Registered
Car shop does not scare me There is a shop here in town that I use all the time for "basic" refresh valve jobs all the time
Kinda looking for some one with a little turbo busa experience so I cn discuss wheather valve size changes or maybe a blank canvas is the way to go
 

KZScott

Registered
leave the big valves in. we go to bigger valves on really high hp builds, and a mild set of cams.
do the chamber mod to knock down that bridge between the exh valves if its still there.
if the valves are sunk a bit it will kill compression and make it feel lazy. can always shave the head to bring that back if thats the case. maybe it was cam timing also?
 

202mphbusa

Registered
leave the big valves in. we go to bigger valves on really high hp builds, and a mild set of cams.
do the chamber mod to knock down that bridge between the exh valves if its still there.
if the valves are sunk a bit it will kill compression and make it feel lazy. can always shave the head to bring that back if thats the case. maybe it was cam timing also?
Cam timing was 105/105 yes the bridge was knocked down and the valve were sunk down
measured comp at the time was 8.2-1 so that was 90% of the problem
as was the fact I was running a gen1 single stage lockup, the bike would leave okay, lockup would come in , pull the motor down to 4k and BOOOOGGGGGGGG
 

KZScott

Registered
Cam timing was 105/105 yes the bridge was knocked down and the valve were sunk down
measured comp at the time was 8.2-1 so that was 90% of the problem
as was the fact I was running a gen1 single stage lockup, the bike would leave okay, lockup would come in , pull the motor down to 4k and BOOOOGGGGGGGG
get that same setup back to 10:1 and it will be a whole new bike
 

Sputter

Registered
Isn't 10-1 a bit high?
Not necessarily! Its the application and combination that is important! you can throw any combination together almost and make it run, but likely not the way it should. So you take and build a low compression large turbo, long wheelbase small street tire bike that makes 600 HP on the dyno and put it on the street and get beat by a 350HP higher compression smaller turbo, short wheelbase bike. Put a slick and bar on the small turbo bike and would still give the larger turbo bike fits in the 1/8 mile and put down the number every run instead of 1 out of 3. The larger Turbo lower compression will make it out the back faster in the 11/4 or LSR though. Everything has its place!1
 

202mphbusa

Registered
I know compression is a huge thing
my FZR1040 I put this STUPID HUGE ported head on it
raising the CR to about 14.5-1
drivability was hugely improved

Man I am old when does the learning stop my brain is full
So my "B" motor that I am building is really going to be my A motor but Hugely different than the one in there
Not 100% sure about head work yet
my plan was to just freshen the big head and maybe do the smaller vales
 

sportbikeryder

Registered
Stock bore, stock intake size, +1mm exh is what we typically run on our prostreet heads. 81 or 83mm bore. The oversize valves you have aren't a problem, nor are the oem guides.

I do many of the CNC heads that come through the shop. I will never understand why some shops try to sell guide replacement as an "upgrade" on many heads. Sure, I replace guides, but as a repair. Other than use of some extreme cams, i see no reason to replace guides for the sake of doing so.
 

Sputter

Registered
Stock bore, stock intake size, +1mm exh is what we typically run on our prostreet heads. 81 or 83mm bore. The oversize valves you have aren't a problem, nor are the oem guides.

I do many of the CNC heads that come through the shop. I will never understand why some shops try to sell guide replacement as an "upgrade" on many heads. Sure, I replace guides, but as a repair. Other than use of some extreme cams, i see no reason to replace guides for the sake of doing so.
I think it is piece of mind most of the time, I know it is for me. Maybe you have a head you don't know the history on, even if they look good why not spent a few dollars more and be sure? When spending 2000.00-4000.00 on a head it is cheap piece of mind for me.
 



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