Customer asked if I can skim a BMW zorst manifold . First step on the coarse linisher,I check it on the surface plate,the end on the right has a 25-29 thou gap,the other 3 ports all touch down flush on the plate,this could be too much to reduce by linishing,to mill this would involve a significant time involved in making fixtures to bolt to,how much value is in these things before I plunge in with a price?
- Thread starter nickk
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oldbikedavey
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Blue and re-linish.
It's a car, and they get built to the nearest inch.
Nobody is going to be going round the Isle of Man on that crock of rubbish.....
It's a car, and they get built to the nearest inch.
Nobody is going to be going round the Isle of Man on that crock of rubbish.....
I have no idea on value of this particular one, but having one port distorted on a cast iron manifold while you can torque them down and they flex and seal, its also a recipe for the manifold developing cracks a few months after its torqued down and gone through some heat cycles.
There's a large % of 101fc exhaust manifolds with cracks in them due to this and they fetch a premium price for uncracked ones as a result. People are asking hundreds of pounds for one side only and I think the rh manifold is even pricier...
There's a large % of 101fc exhaust manifolds with cracks in them due to this and they fetch a premium price for uncracked ones as a result. People are asking hundreds of pounds for one side only and I think the rh manifold is even pricier...
brightspark
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you could soon rasp off 30 thou off it with a course belt on a linisher
Barking Mat
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Are thou tolerances that important on an exhaust manifold ?
I've never even thought to check, but I'm talking boats.
I've never even thought to check, but I'm talking boats.
Barking Mat
Cuddler of hedgehogs.
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I would have thought so.
oldbikedavey
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I might have to get another linisher.....
Agroshield
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When assembling, is is common practice to check the mating surface on the head?
When asking about tolerances, it is the interaction of the two parts that is the final arbiter.
If both are made to +/- 5 banana tolerance, there could (in theory) be a 20 banana gap if two highs and two lows happen to co-incide.
If that's the case then double up on the gasket on the port that's out of line.
Don’t know he just bought the manifold in.
Yes @brightspark another session got it down to 0.009”,so I’m happy it’s acceptable.
