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Sheepers latest Ms75


Evan

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Since you're running NA you probably won't be needing the squirts unless you plan on a bit of track thrashing / sustained b-owts. I'm pretty sure their purpose is piston cooling rather than lubrication.

Did you have a spare turd crank at all? I wouldn't mind stroking my shitter out. 

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Cheers for your thoughts. 

Funny story about the cranks I had. 

Basically I had two,  one looked a bit worse for wear and one was excellent except number 4 main was a tiny bit scratched looking. 

So I set the better looking one up in the lathe to machine the nose to take the smaller drive pulley for the 5M and that's when I discovered the crank was bent.  Which was what caused the engine to grenade in the first place. And that's why I ended up with all the broken 7M junk. 

So the "bad" looking crank was perfect and that's the one I used. 

And whoever built the 7m before me never checked the crank for runout. And I bet it would have been super tight to turn as well. 

Should have been spotted before building a whole engine but I guess not. 

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Pretty impressive to bend a crank, surely the head would have ejected out the bonnet before that. I had two 7Ms once and basically gave them away, now they're a little harder to find. I wonder how good an AliExpress crank would be.. 

What's your thinking behind removing the squirts? Running thin oil and wanna ensure you retain pressure? 

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Na,  I just wanted some other perspectives in case there as something in missing. 

Is not a turbo engine bit it should rev. 

And the pump should handle it fine, it's how it was from factory. 

 

I'm kind of leaning towards running them just because they're there and they'll more than likely work to fling a bit more oil at the gudgeon.

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2 hours ago, sheepers said:

Oh and just to be clear the pistons should make it about 13 to 1 CR so it'll make a bit more heat at the top end. 

13:1 is pretty high for static I guess you already know you'll be on high octane fuel 

I think it would be worthwhile to keep the squirter to keep things cool . Will help prevent detonation having another cooling system 

Have you worked out what the dynamic compression is with your cams? 

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If you want to fine tune individual cylinder trims and shit and get 10/10ths out of a turd then yeah go nuts with full sequential, otherwise just run a crank sensor hidden somewhere on the flywheel and run wasted spark and batch fire.

You might be able to tune a better idle and start up with full sequential which may make a difference with the big cams and compression since you can blast all the fuel in on a single pulse, but I dunno how big a difference it'll really make.

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So,  thinking about it I can do cam angle really easily.

There is a hole in the side of the block and just inside that hole is a shaft that spins exactly half the speed of the crank for some reason. 

I can attach some sort of "trigger" to that shaft and a pick up of some sort to "see" that "trigger".

The crank however might be a bit more difficult. 

And it goes without saying that i want to hide it so its not obvious 

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It's almost like a dizzy once ran off that shaft

/ The same thought crossed my mind

A lot of modern engines run the crank sensor off a tone wheel on the flywheel, perhaps you could attach something or machine some slots into the back of that and hide the sensor under the manifold? Or cut a tooth off the ring gear :-D

I was gonna cut a tone wheel into the front pulley and mount the sensor off the lower timing cover, but I wasn't fussed about hiding it.

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