Rebuilding Apex motor after overheating

[rxrider]

http://www.ty4stroke.com/viewtopic.php?p=466478#466478

Take a look at this thread and let us know what you think.

Thanks
rxrider

 

[Ported Hornet]

Cool thread! Good luck on the rebuild.

 

[snoman]

interesting to do some mechanic there.pretty sure you'll get it running like new.

 

[MUSKOKA APEX RTX 07]

Talk To Rockerdan and he can help you with details he rebuilt his this summer !!!!

 

[Charged RTX]

Did Dan blow his up with the NOS?

 

[ROCKERDAN]

I have over 100 pics similar to those when i rebuilt my motor last summer.....mine let go due to NOS....my head was just slightly out of spec(warpage)and I had one cylinder pushed out 10mm into an eggshape....so I had to get a complete new upper and lower case....along with 1 piston,1 set rings and 1 rod.....all new main and rod bearings too....be sure to replace the head studs too,as i had one snap on retorque.

its a great motor to work on once its on the bench,very easy IMO....its removing it from the sled that sucks the most..lol.

Dan

 

[rxrider]

Thanks, I know, it's my 6th build (twice on my own turbo sled

ROCKERDAN, if I need any info I may ask you. I have never done bearing changes, only piston changes and block teardowns/rebuilds.

 

[rxrider]

This engine was in a stocker with only 15 miles on it. Overheated for a short periode, 5 miles at the most.

 

[ROCKERDAN]

yah i wish i knew what could be possible issues to look for on overheat....the shop manual is good with checking all specs and wear limits as Im sure you know.

as far as bearings...you need to plasti-gage all the main and rod bearings...to check to see how they spec out....there are different color bearings you order....I just ordered the medium size bearing to start and they were NOT within spec when i plasti-gaged them.....so I had to order another size after.


also,to begin with the manual shows you how to take the crank numbers and case numbers to come up with a bearing number to order...pretty cool stuff......I enjoyed building it up alot.....it was the removal from chassis that sucked...so much to tear down to get it out!....lol

Dan

 

[rxrider]

Thanks Dan

Can you tell me more about the plasti-gauging? I have never had the need to change out bearings on the 4strokes. I have mostly dealt with leaking head gaskets, blow pistons, rings and cylinders due to deto.

Do you have the equipment to plasti-gage at home? If so, where to get it? I have most of the tools needed for the 4stroke engines, still need a few tools tho. I have been buying tools whenever needed

We will take the head to a machine shop close by, they have the tools to measure the head and block for straightness. They also have the equipment to measure the cylinders for out of round.

Thanks
rxrider

 

[Kaz]

You should posts this over on the turbo/supercharger form. Lot more guys over there with experience rebuilting these engines.

Kaz

 

[87gtNOS]

scroll down this page....this guy shows pics and explains for you (so I don't have to!!) I sell the stuff, but I am in Toronto!

http://www.iroczone.com/projeng02.html

http://www.aircooledtech.com/plastigage/

 

[ROCKERDAN]

plasti-gage is really cool little stuff...i think it cost me 15 cents..LOL...the shop manual goes into detail on this procedure...

its basically plastic spaghetti.....different colors for different sizes....buy it at any automotive shop....you simply bolt together you rod caps OR main bearing/caps(or in our case bottom case).....with a peice of plasti-gage laying between the bearing and crank/rod.

then you UNBOLT the entire part...and you CHECK THE squeeze-out(for lack of better term) of the plasti-gage....the package has sizing on it,and you just compare it to sizings and it will tell you what your clearance is....in either MM or thousands....

then you just compare yours to the shop manual SPECS and when you are within spec,you have the proper COLOR bearing.

but use the CODE sequence in shop manual,which will point you to which color bearing to buy first...i think there are 4 or 5 different spec bearings(colors)....each just slightly different in thckness....

this is for rebuilding motors with either a MORE warn crank or a like new crank....not every one is exact same when you get the these tolerances...

very cool stuff....and ofcourse the shop manual is a must but it does cover the engine buildup pretty good....anything else comes up,PM me anytime or call me.

some pointers you may already know...be sure to use NEW rod bolts(at caps) as these are stretch bolts,do not reuse....also,i recommend new head studs....and when all is done,BE SURE TO PRIME THE OIL PUMP at initial startup.....i can go over that procedure when you are ready....otherwise motor gets no oil!

Oh yah...let me try to attach a pic of my plasti-gage here....i throw in some pics of when my motor went down too..lol

Dan

 

[rxrider]

You should posts this over on the turbo/supercharger form. Lot more guys over there with experience rebuilting these engines.

Kaz

I have done that with a link to the original post in the 4stroke Garage forum

I thought it could be of interest for the non turboed guys as well

This engine will be sent out to be repaired and rebuilt. There were little damage done to the engine, the owner have decided to do it right this time, having the engine built from the ground and up. Strenghtening the rods, cylinders and block, low compression pistons and so on.

 

[SumpBuster]

I didn't do it myself, but I remember my dealer needing to match numbers off the crank with bearings? When I cooked my 03, it needed a new crank, mains, rods, bolts and a sumpcover. Top end was fine. A bud has it now, and 5000 miles later runs like a bear...very cool motors, imo. It was the first one he'd taken apart, and it was no fun getting that motor out of the chassis, like Dan said..LOL.