Compression breaking is

1) Tranny is gear
2) Your foot is off the throttle

 

http://www.humvee.net/hid/engine/engbrake.html

I found an explaination of it here, thanks Rocket. I have
learned something today So for all you dyno
guys... 3rd gear pull... 8K... take the car out of gear!

 

how about if i don't go as light as an 8.8? say if i go to a 12.5lb flywheel instead? or even an ITR flywheel? will that be ok on a stock b16a2 valvetrain?

 

Geez.. listening to all this is making me scared... i just bought an 8.4 pound flywheel for my d16 and now i'm hesitant to put it on....

 

It has to do more with your driving habits.

Just try to avoid unecesary downshifting and compression breaking. That's bad for the motor.

 

i have stock valve train with a Spoon 8.8 pound flywheel, i havent had any valve float problems as far as i know. Ive had two valve adjustments since i had the engine (one recenltly i think its my TDC sensor though thats cause my rough idle) So what your saying Rocket is that if you have stock valve train its bad to let your foot off the gas in gear if on it or not? that wouldnt seem to cause a dramatic change in rpm vs stock right? what would be syptoms of rod bearings going out or excess where on your valve guides and such?

 

Your valve train tolerances will get sloppy and you'll gradually lose pwer sooner than normal due to your valve to guide tolerance becoming looser, you're exhaust vavles want be able to cool properly. Your rod bearings will want to take a crap.

Remember avoid.

1) Compression Braking/Letting off in gear (Even on dynos)
2) Unecessary Up shifts

Trust me on this. Your engine will thank you. I've seen the effects of this style of driving on cylinder heads and one of them has to be completely redone because of this.

 

Wow guys great thread! I love it.

Great infor ROCKET, I never really look into the aspect of how much valvetrain takes the beating.

I just has one more question/topic that you could coment more about how compression breaking is bad?
I mean I know that when your in 2nd or 3rd gear and reving at like 4-5k and then you let off the gas and your car is REVing on vacume and slowly slowing down is BAD

But what about daily driving compression breaking? like driving 30mph in traffic in 3rd gear at you let off the gas and the car is @ ...2800rpms is that stil BAD for the motor? I'm talking about daily driving not when your trying to accellerate really fast in a lower gear and you let off the gas pedal...


Did i make sence?

 

rocket,... will an ITR flyhweel be ok for a stock valvetrain? or is it still pushing it? how about a 12.5 lb? please respond. thanks

 

Yea I mite get the ITR flywheel with a set of ITR/Excedy clutch for my EM1 also.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by spoonek4 &raquo;</TD></TR><TR><TD CLASS="quote">Yea I mite get the ITR flywheel with a set of ITR/Excedy clutch for my EM1 also.</TD></TR></TABLE>

are you running on stock valvetrain as well? that is the combo i will most likely be going with

 

Yup COMPLETELY stock. And not planning for engine mods anytime soon. I can't master my car so just gonna get some better brakes pads, tires, suspension, clutch etc for now.

 

Rocket your so right its almost SCARY!!!! Will upgraded valvetrain help ease it a little?

 

I wonder if it would be recommended to upgrade to a better timing belt
under such stresses?

 

i been looking for a flywheel..... but cant really find much stuff for an h22a.. anyone have a good site/place?? thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Charlie Moua &raquo;</TD></TR><TR><TD CLASS="quote">Wow guys great thread! I love it.

Great infor ROCKET, I never really look into the aspect of how much valvetrain takes the beating.

I just has one more question/topic that you could coment more about how compression breaking is bad?
I mean I know that when your in 2nd or 3rd gear and reving at like 4-5k and then you let off the gas and your car is REVing on vacume and slowly slowing down is BAD

But what about daily driving compression breaking? like driving 30mph in traffic in 3rd gear at you let off the gas and the car is @ ...2800rpms is that stil BAD for the motor? I'm talking about daily driving not when your trying to accellerate really fast in a lower gear and you let off the gas pedal...


Did i make sence?</TD></TR></TABLE>

Not that bad. The faster your motor slows down the car the worse it is for your motor. Granted sometimes you gotta hit 2nd and shoot the rpms to 7k to take on some guy doing a 6k rpm flyby but that should happen ofte (I hope )

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by H22AEG &raquo;</TD></TR><TR><TD CLASS="quote">i been looking for a flywheel..... but cant really find much stuff for an h22a.. anyone have a good site/place?? thanks</TD></TR></TABLE>

Action Clutch carries the really nice ASSCO ones. Price is around high 300's from any Action dealer.