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typical decking amount
Posted: Mon Jan 18, 2016 7:32 pm
by Seight-V8
hello all,
Does anyone know how much they normally deck the block head faces after fitting top hat liners?
Taking block to chesmans later this week and forgot to ask.
cheers
scott
Posted: Mon Jan 18, 2016 8:12 pm
by kokkolanpoika
As minimal as could.. ~0.1mm approx? What ever needed..
I build one engine to my friend, and engine numeber still look good after they mill deck..
Posted: Mon Jan 18, 2016 8:23 pm
by Seight-V8
sounds good, will speak to them on Thursday and see what they can do, hoping to get it back late Friday....
cheers
scott
Posted: Mon Jan 18, 2016 10:15 pm
by seight
Probably worth getting them to check both banks are the same height while they're at it.
Posted: Wed Jan 20, 2016 10:16 pm
by ratwing
FWIW my engine from Turners looks like it was decked so much the engine numbers were removed - I say this because the font is different to what I've seen on others (and IIRC the compression ratio stamp has gone too).
I haven't run the engine yet but I reckon Turners know what they're doing.
Posted: Thu Jan 21, 2016 7:24 pm
by seight
I had mine decked and the number as good as went so I had to redo it.
If you're lucky, like me, then your inlet manifold still lines up after too
I went from tin to compo gaskets at the same time and it all lined up perfectly afterwards.
Good luck.
Posted: Sat Jan 23, 2016 10:01 am
by Seight-V8
Had by block top hatted by chesman's in Coventry yesterday, and they've done an excellent job, with excellent service.....
Will recommend them anytime.
Just need to measure how much was removed from the head faces during the decking, as the engine number has now gone too.....
Then I can work out compression ratios for the next part of my re-build.
I am hoping the decking was minimal but I am not too sure.
regards
scott
Posted: Sat Jan 23, 2016 12:30 pm
by -88-
How deep pistons are at TDC in undecked RV4.6?
In my tophatted 4.6 pistons are 0.2mm above deck at TDC because i want them that way.
Going to use composite gasket so piston
to head clerance is going to be approx 1mm. Am i right?
Posted: Sat Jan 23, 2016 4:21 pm
by seight
I guess a lot will depend on your cam duration. You might get away with piston to head clearance but when I did mine I had valve clearance problems.
Posted: Tue Jan 26, 2016 10:37 am
by SimpleSimon
I have notched pistons with a 238 cam and my limitation was not VTP clearance although getting marginal it was piston to head clearance
as my pistons pop out of the block I am just outside the considered minimum
but mine is a 4.0 I removed about 1.3/1.5mm from the decks IIRC which also gives the usual inlet manifold issues that had to be corrected