| ausmini https://www.ausmini.com/forums/ |
|
| Oversize Exhaust Valves https://www.ausmini.com/forums/viewtopic.php?f=2&t=26453 |
Page 1 of 1 |
| Author: | Anto [ Fri Jan 05, 2007 11:16 am ] |
| Post subject: | Oversize Exhaust Valves |
Looks like I've got to get this 12G202 head I have here serviced as the exhaust valves are fairly recessed. I'm concerned that they might be so far gone that o/s valves need to be fitted. Anyone know how much extra work this would be for the machine shop to do? I have four of the right valves here anyway that are in good condition, I'm thinking I might just get them fitted regardless, and also get some extra meat taken off the deck to increase C/R, may as well. |
|
| Author: | willy [ Fri Jan 05, 2007 11:24 am ] |
| Post subject: | |
Take it to a machining shop. They will fit new valve seats, and lap the existing valves in accordingly. A new angle will most likely be cut on the valve. |
|
| Author: | Lillee [ Fri Jan 05, 2007 11:30 am ] |
| Post subject: | |
Hey Anto, how's things? If you already have the smaller 1098 1.151” exhaust valves, you can fit 1.215” exhaust valves. The alternative is to machine up some hardenned seats which means you can use the original smaller valves. I would go larger valves, when they eventually recess (won't happen for many miles if you use a Fuelstar or the like) then cut and press in the hardenned seats later on, giving you more life on the 202. |
|
| Author: | Anto [ Fri Jan 05, 2007 11:49 am ] |
| Post subject: | |
Yeah I might go see the machine shop. This is only a budget head anyway, although I wouldn't mind giving it a light going over with the grinder to unlock a few extra horses and torques. Whats the worst that can happen.... 
I have another couple of 202s here, one is already converted to unleaded, but unfortunately I'm 99% its cracked, although I guess it could be warped... we'll see. |
|
| Author: | willy [ Fri Jan 05, 2007 11:52 am ] |
| Post subject: | |
Anto wrote: Whats the worst that can happen....
Where do I start 
|
|
| Author: | drmini in aust [ Fri Jan 05, 2007 12:20 pm ] |
| Post subject: | |
Lillee wrote: Hey Anto, how's things?
If you already have the smaller 1098 1.151” exhaust valves, you can fit 1.215” exhaust valves. The alternative is to machine up some hardenned seats which means you can use the original smaller valves. I would go larger valves, when they eventually recess (won't happen for many miles if you use a Fuelstar or the like) then cut and press in the hardenned seats later on, giving you more life on the 202. Chong you are talking 1275 heads- in a 202 they are 1.000", not 1.156". you can get 1.062" O/S ones. Otherwise, fit inserts. 
|
|
| Author: | 9YaTaH [ Fri Jan 05, 2007 1:52 pm ] |
| Post subject: | smog |
Anto wrote: Yeah I might go see the machine shop. This is only a budget head anyway, although I wouldn't mind giving it a light going over with the grinder to unlock a few extra horses and torques. Whats the worst that can happen....
I have another couple of 202s here, one is already converted to unleaded, but unfortunately I'm 99% its cracked, although I guess it could be warped... we'll see. Theres a smog head sitting on my garage floor that I keep tripping over 
|
|
| Author: | cush [ Fri Jan 05, 2007 2:36 pm ] |
| Post subject: | |
you should put it on a bench or in a cupbaord then... 
|
|
| Author: | Anto [ Fri Jan 05, 2007 2:38 pm ] |
| Post subject: | |
998 smog head? I usually find the wheelie bin a good place for em, right next to all those 850 heads
|
|
| Author: | slinkey inc [ Fri Jan 05, 2007 2:38 pm ] |
| Post subject: | |
Lillee wrote: Hey Anto, how's things?
If you already have the smaller 1098 1.151” exhaust valves, you can fit 1.215” exhaust valves. The alternative is to machine up some hardenned seats which means you can use the original smaller valves. I would go larger valves, when they eventually recess (won't happen for many miles if you use a Fuelstar or the like) then cut and press in the hardenned seats later on, giving you more life on the 202. I've been using one since the rebuild of my 12G940 (Mk2 'S' one) head on my car. Has anyone seen what these do in the long term? At the moment the car is fine, only mini at the dyno day not to smoke  But this is obviously due to the motor being only 6000k's old.
|
|
| Author: | Anto [ Fri Jan 05, 2007 2:42 pm ] |
| Post subject: | |
I run flashlube and haven't seen any reason not to. Haven't tried any of those catalysts or whatever but a mate of mine has been running one for years with no probs. With this head of mine, the previous owner obviously did something wrong, the exhaust valves are pretty badly recessed. The engine is old enough that leaded petrol would still have been at the pumps so I dunno ??? The rings and bearings were like new and I could see hone marks on the bores. |
|
| Author: | 9YaTaH [ Fri Jan 05, 2007 5:45 pm ] |
| Post subject: | Carz |
cush wrote: you should put it on a bench or in a cupbaord then...
No room...too much other K-rap  Part of the problem is having six cars of various types in the yard to look after 
|
|
| Page 1 of 1 | All times are UTC + 10 hours |
| Powered by phpBB® Forum Software © phpBB Group http://www.phpbb.com/ |
|