Broke predator block

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Vtbowhunter3

New Member
#1
#1
This is in a mini racing snowmobile for my son with a JR clutch cvt system. Broke one broke when the side cover came loose earlier in the season. Rebuilt the engine and installed a stud kit with solid dowels and here in the 2nd lol. The engine has a +.20 rod with a clone outlaw racing plus stroke crank. NR 274 cam with a Honda 18cc head milled .080 will a billet side cover take care of this issue? I’m assuming the stock cover can’t take the vibration from the heavy clutch. Or do I have another problem? Thanks
IMG]https://uploads.tapatalk-cdn.com/20180214/904ba58df10311d2f7ae8450be53e5c5.jpg[/IMG]


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trinik7597

trinik7597

Active Member
#6
#6
You said the magic word !!! Gx200 ... The billet side cover should take care of it but the predator blocks are commonly weak inferior castings accept the first gen non hemi ..check your end play you can shim it if it is too loose ..
 
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Vtbowhunter3

New Member
#7
#7
trinik7597 said:
You said the magic word !!! Gx200 ... The billet side cover should take care of it but the predator blocks are commonly weak inferior castings accept the first gen non hemi ..check your end play you can shim it if it is too loose ..
Click to expand...
Haha ok! I have a GX200 sitting here maybe it would be wise to build that when I get my side cover...


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trinik7597

trinik7597

Active Member
#8
#8
Unfortunately all your parts won't cross over ... And you would be giving up some displacement .. But you can never go wrong with a real Honda gx motor ..
The billet side cover will stiffen the block considerably and you can take advantage of the fittings to relieve some crank case pressure if you don't have a vent already .. And the bearings are much better .. I would make sure my end play was pretty damn tight too with that big driver
 
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Vtbowhunter3

New Member
#9
#9
My head, rod, crank, flywheel is all Honda. Only predator parts I have are piston and block. That should all switch over shouldn’t it? Not sure where the piston would sit in a Honda block with that combo. I would rather not lose displacement though. My valve cover is currently vented.


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trinik7597

trinik7597

Active Member
#13
#13
Sorry I see it ...what is the stroke on the clone max stroke crank ? With the stock Honda crank and a plus 20 rod you should have slight pop up depending on the motor .. And you are probably slightly de stroked now ... Is it a hemi block ? If so everything will cross and forget my first statement
 
trinik7597

trinik7597

Active Member
#14
#14
I would swap it over and order a z4m piston from Dover they have different compression heights available .. And get rid of the dished piston that's gonna be in there .. Gerry @ Dover should be able to get you to zero deck or damn close to it .. And you can make up piston to head clearance in the gasket
 
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Vtbowhunter3

New Member
#15
#15
I’m close to zero deck height now with the predator. The crank is +.17 I will give him a call I am still learning a lot and bought a lot of the stuff used. This motor that just broke the block was the first one I had actually put together. Seemed to run good until it leaked oil! Haha


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trinik7597

trinik7597

Active Member
#16
#16
Just my opinion ... If you already have a gx200 and all. You have to buy is a piston and some gaskets to swap everything that's what I would do .. You may have already stressed the block as well as the side cover and it just hasn't shown up yet ...
 
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Vtbowhunter3

New Member
#17
#17
This block is junk it broke out by one of the solid dowels I would need to buy a whole other engine now. I think you have talked me into it.


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noseoil

noseoil

Active Member
#19
#19
0.010" give or take should be ok. I used a HF dial gauge & made a simple holder to fasten it to the block for mine. It's crude, but it works well enough, nothing fancy but just needs to be a solid rest for measuring things when pushing & pulling. Aluminum angle, screws & 2 bolts will do it. Too tight & it will blow off the side cover every time at speed. A heavy clutch will need the extra support bearing to get rid of crank flex, too much mass pulling on the case isn't good. Use studs & red loctite to hold them into the block (hopefully) for good...

Crnk-Setup.jpg
 
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