![]() |
#1 |
Join Date: Jan 2022
Location: Gatesville Texas
Posts: 161
|
229 head question
I've purchased a new head and a tt250 (thin) head gasket. I going to see
if I can remember how to do some porting (it's been about 35 years). Has anyone done the chamber volume math enough to know how much deck to cut to get to between 9.5 to 10 compression? I have not measured the tt gasket but it appears to be about half the stock 0.040. gasket. I don't remember the math and I don't have an accurate way to measure chamber volume. tia
__________________
2021 RPS Hawk "IKEA" (Came in a box with no instructions) 110 main jet 1washer,2.5 sprockets and the cat fell off( with a little help) 1984 Honda V65 Magna "Daddy's Little Monster" To whoever stole my anti-depressants. I Hope Your Happy ! |
![]() |
![]() |
#2 |
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,098
|
The thinner HG on it's own combined with the TT250 head will give you the same 9.6:1 compression that the TT250 comes with. The thinner gasket gives about half a point on it's own, and having compared a Hawk and TT250 piston, if there is a difference in volume, it's no more than a couple of CC's off as the dimensions are more or less the same.
If your goal is 10:1, then take another half a mm off the head or jug deck. I don't have all of my data in front of me and I would have to dig out my notebook from the abyss, but those are the figures I remember off the top of my head.
__________________
Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124 |
![]() |
![]() |
#3 | |
Join Date: Jan 2022
Location: Gatesville Texas
Posts: 161
|
Quote:
My goal is to run pump gas without mixing av gas. I also have a 4degree key waiting to see if I can get away with, but it's pretty easy to undo if I can't. Thanks for the info.
__________________
2021 RPS Hawk "IKEA" (Came in a box with no instructions) 110 main jet 1washer,2.5 sprockets and the cat fell off( with a little help) 1984 Honda V65 Magna "Daddy's Little Monster" To whoever stole my anti-depressants. I Hope Your Happy ! |
|
![]() |
![]() |
#4 | |
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,098
|
Quote:
You will be ok. These CDI boxes have super conservative timing. ![]()
__________________
Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124 |
|
![]() |
![]() |
#5 | |
Join Date: Jan 2022
Location: Gatesville Texas
Posts: 161
|
Quote:
![]()
__________________
2021 RPS Hawk "IKEA" (Came in a box with no instructions) 110 main jet 1washer,2.5 sprockets and the cat fell off( with a little help) 1984 Honda V65 Magna "Daddy's Little Monster" To whoever stole my anti-depressants. I Hope Your Happy ! |
|
![]() |
|
![]() |
![]() |
Tags |
head, porting |
|
|