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Discussion Starter · #3 · (Edited)
Oil Scraper Ring also serves as the Pin Retainer? :confused:
Harold
Yep kind of a cool idea hey?
The two plugs come in at 60 grams together but, there was no room for the standard spiral locks with this custom slug.
Live and learn....and cross fingers,toes and any other body parts that the combo works!

Notice also that it has a thermal barrier coating applied. I was very surprised with the roughness of the coating. Is that normal?
 

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Yep kind of a cool idea hey?
The two plugs come in at 60 grams together but, there was no room for the standard spiral locks with this custom slug.
Live and learn....and cross fingers,toes and any other body parts that the combo works!

Notice also that it has a thermal barrier coating applied. I was very surprised with the roughness of the coating. Is that normal?
I've done this on a few sets of pistons, but the plugs were always teflon or something similar, not aluminum. My turbo 2.5 Opel pistons have this feature, since I lowered the ring stack for boost tolerance.

Yup, a lot of the TBC's tend to be quite rough, that's totally normal.
 

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Discussion Starter · #5 ·
Yup, a lot of the TBC's tend to be quite rough, that's totally normal.
Any tuning hints on how to take advantage of the TBC would be appreciated.
Hey, I'm always looking for a edge since this will be the first set that we've tried.
The nice thing is that I've got a very good history and notes with this car going back 3 years.

The things learned with the 421 SBC will be translated to the Opel.
 

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Any tuning hints on how to take advantage of the TBC would be appreciated.
Hey, I'm always looking for a edge since this will be the first set that we've tried.
The nice thing is that I've got a very good history and notes with this car going back 3 years.

The things learned with the 421 SBC will be translated to the Opel.
You can go a few degrees more (or less) on the timing, or a bit leaner. Basically you have a higher EGT tolerance.

But it just lends a safety margin really, if you want to get radical with the tuning then you really need to do the TBC to the valves and the chamber as well, and a heat-transferance coating to the valve stems too. Otherwise the weak links will just get moved around, but not eliminated. What good is having heat resistant pistons if the exhaust valves melt!:eek:
 

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Yeah thats a very good point with the cylinder temps.

Would a reverse cooling system flow help lower an elevated chamber temp on the 1.9L?
I did modify a junk head and block once to see how hard this would be. I ended up redirecting the water pump flow to the head, and cut a window out of the RF corner of the block to intercept the return to the radiator. Never tested it in use though. I was too worried about air pockets created by trying to flow 'top to bottom' rather than the normal 'bottom to top', and chickened out.
 

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Discussion Starter · #9 ·
Bob I owe you an apology.
I had a local tuner bring in one of his toys running on E-85 the other day.
Yep he popped the headgasket because I didn't fully understand the lambda with a wide band. As penitence I hand wrote out the relationship between Lambda,gas,E85,E100,methanol,propane and diesel.

Lambda is Lambda is Lambda no matter the fuel.

That explains the lifting of the rings back in post 7.....too rich!
 
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