Boost Works Turbo tC Build TRACK VIDEO
05-15-2011, 11:19 PM
#306
Senior Member
SL Member
Join Date: Jul 2007
Location: West Palm Beach, FL
Posts: 3,773
give me a loose motor with a decent amount of blow by over a super tight clearances motor any day of the week. mine has had a good amount of blow by since i got it back in 07 and runs like a champ to this day.
05-16-2011, 07:04 AM
#313
I got zero blowby at all.. like my can is always dry since i put it on like 2 years ago, is that a bad thing? During the dyno i did see some smoke coming from the catch can breather but not as much as the one in the vid
05-16-2011, 05:15 PM
#316
Yep. Piston rings aren't sealing well anymore. The engine is tired.
05-16-2011, 07:29 PM
#317
Senior Member
SL Member
Join Date: Jul 2007
Location: West Palm Beach, FL
Posts: 3,773
ok, there seems to be some confusion about blow by around here, so let me explain a few things. blow by is not necessarily a bad thing. it can be a sign of engine wear or damage on parts like piston rings or ringlands. it can also be a sign of cylinder wall scoring or wear. however, its usually only something to worry about if you notice a sudden increase in the amount of blow by you have.
the amount of blow by a car has is dependent on a many different factors. the two most important ones are piston to wall clearance and ring gap. when building a motor to handle high boost or n2o, these clearances need to be on the high side, thus resulting in more blow by. this is due to the fact that when metal heats up, it expands. im sure we can all understand this concept. the more boost or nawz you throw into the mix, the more heat it will produce, thus more expansion. as the pistons and rings expand, they put more stress on all components of the rotating assembly as well as the cylinder walls. to much expansion will destroy your motor plain and simple.
one way that engine builders combat this is to run a higher piston to wall clearance and ring gap, also know as having a loose motor. this will allow enough room for everything to expand and achieve its maximum seal under high load conditions. this is also the reason that many built motors have loud piston slap, and the reason why srt-4s can run 400+ whp and 11 second 1/4 mile passes while having 175k on the clock. many companies also sell pistons made out of lower expanding metals like 4032 aluminum.
another factor of blow by is how much you are boosting. i would say at least 90% of the boosted tc's on this site are running between 8-12 psi. trd07tc is running 24 psi. so when you see all this blow by in his video don't freak out. remember its a brand new built motor, there's nothing wrong with it. im sure he built the motor like that for a reason.
the amount of blow by a car has is dependent on a many different factors. the two most important ones are piston to wall clearance and ring gap. when building a motor to handle high boost or n2o, these clearances need to be on the high side, thus resulting in more blow by. this is due to the fact that when metal heats up, it expands. im sure we can all understand this concept. the more boost or nawz you throw into the mix, the more heat it will produce, thus more expansion. as the pistons and rings expand, they put more stress on all components of the rotating assembly as well as the cylinder walls. to much expansion will destroy your motor plain and simple.
one way that engine builders combat this is to run a higher piston to wall clearance and ring gap, also know as having a loose motor. this will allow enough room for everything to expand and achieve its maximum seal under high load conditions. this is also the reason that many built motors have loud piston slap, and the reason why srt-4s can run 400+ whp and 11 second 1/4 mile passes while having 175k on the clock. many companies also sell pistons made out of lower expanding metals like 4032 aluminum.
another factor of blow by is how much you are boosting. i would say at least 90% of the boosted tc's on this site are running between 8-12 psi. trd07tc is running 24 psi. so when you see all this blow by in his video don't freak out. remember its a brand new built motor, there's nothing wrong with it. im sure he built the motor like that for a reason.
05-16-2011, 08:42 PM
#320
Just low boost for the most part, car hasnt seen boost over 14psi. 7-8 daily. I thought so no blowby is fine, it just makes me wonder all boosted guys i know gets a good amount on theirs... Or maybe its just my catch can design not so good in trapping vaporized oil
Just pulled out the motor yesterday, its pita to pull out lol.. will be putting it together soon all i need is free time.
Just pulled out the motor yesterday, its pita to pull out lol.. will be putting it together soon all i need is free time.