4cylfiend

iTrader: (1)

Looking good! Those wristpins seem a little thin walled, but i'm sure they will be fine.

EF1.8T

Looking like an interesting build! I'm in

TypeRfit

iTrader: (6)

Nice build, I'm in. Thank you though for being a little more informative about the engine building procedures. Learning some good stuff here.

Runnerdown

Not trying to be a dick, but it's painfully obvious from the pics the piston has hit the head and made marks on both.

Good like with the new build, it should be killer you have a great parts list.

Muckman

iTrader: (2)

Ya know I never even thought about it but youre right. They are thinner than CP wrist pins. Im not worried though.

Muckman

iTrader: (2)

You're not being a dick at all. I even said that theory makes perfect sense. Im just shocked that the damaged bearing would allow .060" of additional movement.

...dick lol

4cylfiend

iTrader: (1)

pm sent

rich7777

True, but there are many builders out there that do this without any issue. I can't see how if it comes off so easy it would matter if its removed or not. Won't it come off anyway after so many miles anyway ? Have you found any problems with removing it ?

4cylfiend

iTrader: (1)

On most bearings, it is a "break-in" coating so to speak.

rich7777

I have to question though, why do bearings need "breaking in" ? There's nothing to really break-in about a bearing from my knowledge. They're not like piston rings to that degree. They should never come in direct metal on metal contact..

TypeRfit

iTrader: (6)

I've rebuilt plenty of dirtbike motors and was taught to break it in how you're going to drive it. If anyone has anymore insight on that it would be helpful.

4cylfiend

iTrader: (1)

I would say its because on the first startup, there isnt going to be any oil pressure so when turning it over, there may be a slight bit of friction until it builds up oil pressure.

Muckman

iTrader: (2)

On that same subject, if you rub off the soft "break in" film to obtain wider oil clearance then you arent really opening the clearance at all. All the bearings will open up the same amount when that film is rubbed off anyways.

shermanyang

iTrader: (1)

Loving this build! Gonna use the information you're supplying for my own build(obviously don't have the funds to go to your extreme) but I think I'm gonna try running on 93 octane vs E85 just cause I hate driving around trying to locate a gas station supplies it.

Muckman

iTrader: (2)

The same applies to 4 stroke engines. You have a limited time window to seat the rings with a fresh hone which requires heavy load, deep vacuum and rpm. The complicating factor is most everyone on here is adding a turbo in addition to breaking in a new engine. So you have to make sure its tuned safely before you "beat on it". I prefer NA if possible or very low boost during break in to keep it simple and safe. Some people break engines in on the dyno where you can minimize the risk while logging miles.

TypeRfit

iTrader: (6)

Makes sense, are you going to be breaking your motor in N/A then?

Muckman

iTrader: (2)

Id like to but I dont have a header that will bolt up to my 3" exhaust. Precision also sells their wastegates with a 1.5psi spring which would be nice. I dont think it would fit my Tial though. I'll rig something up.

rich7777

So are you saying that the coating is to help oil retention on the first start up ? I can't see it doing anything other than helping the oil stick to the bearing. Then again, if you're using assembly lube it shouldn't make any odd's...


I've always seen it as a way to ensure you're seeing the correct clearance more than anything... Sorry if you feel like I've taken your thread off track with this man. I feel that is good to go over some of these things even if they are relatively simple. If we can learn something new then good. If not then it's no problem...

Muckman

iTrader: (2)

This discussion is definitely on track! Ring gap theory, break in practice and bearings are relevant to this discussion. If I didn’t want to discuss the details I would just plop down turbo specs and a 540hp dyno plot. (ballpark)

JDM809

nice build, my sfwd build is somewhat like yours but with a little less compression. i have a 83mm golden eagle sleeved block with custom j.e. high compression pistons (12.5:1) with bigger and deeper valve reliefs and asymmetric piston skirts... compression should help with the spooling of my big turbo...

Muckman

iTrader: (2)

Why bigger valve pockets? Are you running a cam over .500 lift? A few experienced people on this forum will tell you compression will not help spool at all. It will only help you under the curve with more torque (all motor).

gringotegra

Looking at your old motor, looks like it spun a bearing and then the added play it had after let it then hit the head. Not Detonation.


As far as break in procedures, we build and install 45-50 motors a year here. All ranging from 400-800whp Evo/DSM's and a Few subaru's. All our bearing clearances are the same, and depending on power level the PTW is the same also (Higher power = PTW normally looser, Although it varies on what pistons you use too).

We break them in within 100miles for the customers and then tune them. In the 300+ motors we have built over the years, we have never seen any Rings not "Seat" with this break in procedure.

gringotegra

This.


Compression doesn't help spool!

Runnerdown

Something I think should be brought up, the crank still has the factory plugs ***** on the oil holes. I find that this "V" shaped area in the crank will centrifugally collect sludge and debris. If you remove them you find 99% of the time there is crap build up inside there that is nearly impossible to remove by conventional methods. I have not tried an ultrasonic cleaner yet but i think it would work. I have my machinist remove them and tap it for pipe plugs. This junk can dislodge and go right into the bearings so I never chance it. A used or grinded on crank is something I would be very keen on checking.

JDM809

sorry my mistake, valve reliefs are not bigger just deeper. lets just see this is my first race build. i look around this site alot and ask alot of question whenever possible. currently debating on what rods to use and what turbo. but i know alot of people out there running high compression turbo motors. hope they tune in on this thread. like Miller.