anybody run the .20 head shim?

[EXTREME1]

i bought the trx head shim kit came with .20 .30 stock .40 just was wondering which one too run?i run 30% fuel trx 3.3 revo.

 

[lesclaypool]

If you want to run the .20 go for it, but after some running pull the head off and check for pre-detonating/pitting on the button and piston.

 

[EXTREME1]

thats just it i think my style of driving i would perfer the .40 don't care bout top speed i do alot of rock, hill climbing and think the .40 would run cooler and have a lil more torq.but the .20 would make it scream but sacrifice engine life.and what bout temps?i know the .20 would run hotter than the .40

 

[lesclaypool]

Honestly I wouldn't care about temps so much. Tune it right and performance will be optimized and so will engine life.

https://www.rcnitrotalk.com/forum/showthread.php?t=76808

 

[EXTREME1]

i've read that before but it refreashed my memory.thanks so u think just let her eat go .20 and tune it.

 

[lesclaypool]

Yep but watch for pre-detonating.

 

[EXTREME1]

how often should i check it?half tank 1 tank?

 

[lesclaypool]

No no, run 10 tanks through it maybe, you'll know by then.

 

[mrbones]

No no, run 10 tanks through it maybe, you'll know by then.

I think I was told that the stock head shim is the 30.

 

[Extreme RC Mods]

To do it properly the deck clearance should be measure first, then you shim it accordingly. Taking out shims without knowing what the specs are is about as dangerous as cranking your boost in a 1:1 with no wide-band or tuning abilities. It just costs less to rebuild or replace.

lesclaypool's example will work but I would get it up to temp, put a performance tune on it and run it really hard for about five minutes. That's all it should take to show signs that it may be pre-detonating.

 

[EXTREME1]

how do you check deck height.is it the same as the motors i work on?clay/vener gauge?and yes .30 is the stock head shim.

 

[Extreme RC Mods]

Depth gauge.

 

[2revo1maxx]

I would leave it stock. It sounds like you're expecting a miracle to happen with a 3.3, when in reality you will barely see any difference in performance.....and it could be less performance at that.

 

[EXTREME1]

yes run it today it was 70 degs. and had a performance tune on it and with the .20 it started per=deadnating.so i guess i'll try the .40 just to see what that will do.think i'm gonna go with the picco .28 w/mount off ebay for $200.but i've only ran 2 gals. in my new 3.3 so probaly just buy the picco .28 and run the 3.3 till it dies.