mulot30th
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apex mountain crracing 174
apex blower 136 for asphalt racing
osp drag race sled (apex engine based)
Just leakdown tested my apex motor tonight...
Started it to heat the motor up, then:
Got anywhere from 20% up to 50% depending on cylinders.... that is bad......
Ran a compression test to confirm that... 120psi to 145 psi depending on cylinder.
All that with bon stock compression ratio.
My rx1 on the other hand has between 4 and 7% leak down depending on cylinder (cold so must be less leakage when hot) and compression was a bit over 150psi... with 9-1 compression ratio.
I guess its time for a complete rebuild....
Sled has exactly 536km on odo...
I just wonder How could I get 287hp on the dyno with it. I have not riden it since that dyno session, so engine must be in exact same state as on the dyno.
Started it to heat the motor up, then:
Got anywhere from 20% up to 50% depending on cylinders.... that is bad......
Ran a compression test to confirm that... 120psi to 145 psi depending on cylinder.
All that with bon stock compression ratio.
My rx1 on the other hand has between 4 and 7% leak down depending on cylinder (cold so must be less leakage when hot) and compression was a bit over 150psi... with 9-1 compression ratio.
I guess its time for a complete rebuild....
Sled has exactly 536km on odo...
I just wonder How could I get 287hp on the dyno with it. I have not riden it since that dyno session, so engine must be in exact same state as on the dyno.
Torched the exhaust valves again ???
HYFLYR
TY 4 Stroke Guru
Seems like you are always having troubles my man. Could it be faulty install? Just curious?
mulot30th
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apex mountain crracing 174
apex blower 136 for asphalt racing
osp drag race sled (apex engine based)
Seems like exhaust valve are still leaking some...
but there a #*$&@ load of blow by the rings ... a lot of air going into the crankcase.....
One example... with the piston being at 50% of its compression stroke, its around 30% leakdown and it climb steadily to 50% at tdc, so that eliminate the leaking valves as a changing factor...
almost looke like cylinders are tapered
but there a #*$&@ load of blow by the rings ... a lot of air going into the crankcase.....
One example... with the piston being at 50% of its compression stroke, its around 30% leakdown and it climb steadily to 50% at tdc, so that eliminate the leaking valves as a changing factor...
almost looke like cylinders are tapered
mulot30th
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apex mountain crracing 174
apex blower 136 for asphalt racing
osp drag race sled (apex engine based)
will see....
What is the timing of your exhaust can set at?
mulot30th
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apex mountain crracing 174
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bone stock
kinger
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What would happen if you just run it, compression is there. I suppose its a matter of time.
mulot30th
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apex mountain crracing 174
apex blower 136 for asphalt racing
osp drag race sled (apex engine based)
Seems to run okay, just the compression is really down low...
My guess is its a matter of time too..
That is why my je pistons are ordered as well as forged rods. Then I'll crank this gt28 right to its limit!
My guess is its a matter of time too..
That is why my je pistons are ordered as well as forged rods. Then I'll crank this gt28 right to its limit!
I would definatly run it for a bit on the snow then check again before tearing down, could be you burnt some carbon off on the dyno, it may self heal!!
mulot30th
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apex mountain crracing 174
apex blower 136 for asphalt racing
osp drag race sled (apex engine based)
vcrash said:
i love those 4 last words
Sterling
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Stupid question, but is it possible the engine just hasn't fully seated the rings yet? 530 k is only 300 miles, My 05 rx-1 drove me crazy when I tried to sync the carbs at about 500 k. Once I had 1500 on it I tried it again and it was bone simple. The only thing I can think, was the vacume signal was different on all four due to the low time on the engine. I now have 2200 on mine, 600 with sc boost, and I swear it still is getting stronger. I know you are not trying to sync carbs (ain't none!), but maybe something to consider. You mentioned a lot of air in the crankcase, which could mean rings not yet seated. Just my two pennies. Wish you all the best!
kinger
VIP Member
I say run till she blows, then repair till then it could just be a sticking valve train from lack of use or something simple. Rare that problems take care of them selves but if she is feeling strong run her!
With low miles on it I would think it very well could be the rings are not set yet. You could run it until your burning blue then do a rebuild if it is in fact the rings.
