How long do you wait after a engine build?

[kinger]

Wondering how long you wait after a engine build to really crank up the boost? I have nitrous on mine and wondering what peoples thoughts are on when to use the nitrous again. 500 miles? My rings are not new but all the bearings are. Thanks!

 

[Ted Jannetty]

Wondering how long you wait after a engine build to really crank up the boost? I have nitrous on mine and wondering what peoples thoughts are on when to use the nitrous again. 500 miles? My rings are not new but all the bearings are. Thanks!

The ring seal is the biggest thing, the bearings only need a couple heat cylcles and they are ready.

 

[wantboost]

what about a full rebuild,cylinders honed,all new rings,bearings.how long to wait before any high rpms,nitrous,boost.how long to seat rings?

 

[Ted Jannetty]

what about a full rebuild,cylinders honed,all new rings,bearings.how long to wait before any high rpms,nitrous,boost.how long to seat rings?

It is difficult to say for sure but a couple hundred trail miles should do it.

 

[mulot30th]

what about a full rebuild,cylinders honed,all new rings,bearings.how long to wait before any high rpms,nitrous,boost.how long to seat rings?

Same question here..

my tapex engine is almost done, and fully rebuilt, so do I need to wait like 300 miles?


I don't ride trails, only powder (mountain) and 300 miles will be awful long....


Can I at least run like 6-8# of boost?

 

[TWIN TURBO]

Rebuilds are't quite the same as new engines!!!!
New engines have cam bores and camshaft/lifter which are metal to metal wear surfaces that need run-in time to mate themselves. Yamaha says 300 miles, I would agree.
Rebuilds are a whole new story. What kind of rebuild? Did we just throw rings in it, no honing, if we honed it did we use DIAMONDS or a brake hone style hone? Did we meet factory surface finish or is it a mess? I've seen some all kinds, mostly THE MESS type, unfortunately for the owner. Most shops can't hone nickasil properly.
This make's a big difference in break-in ring seal being most important. Like Ted said bearings need little break-in if any. Camshafts need more attention, and rings need proper cylinder finishes, most important on rebuilds. If all is correct, BIG IF HERE, 10 runs starting out at lower power levels and RPM, working up to higher power levels and higher RPM will seat the rings If the cylinder finishes were right.
Lets go racing!

 

[kinger]

Cool I'm going to go beat the wee out of mine this weekend and get some confidence it is going to hold up, this sled hasn't proved it is reilable yet, but its not the sleds fault. Thanks!