Belgian1979vette
Well-known member
Anyone know how finish machined the dart shp's come from the factory ? I mean, cylinders honed to finish size with deckplates and main line align honed, parallel deck etc.
Dart shp
- Thread starter Belgian1979vette
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gkz
Well-known member
I would just ask Dart; They're very good with getting back with you. See if this email still works; they'll fwd to appropriate dept.
[email protected]
[email protected]
Twin_Turbo
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Contact CNCBlocks Carl on this forum.
CNC BLOCKS
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The SHP blocks that come from Dart have a 9.025 to 9.028 decks if you want that much quench thats fine but I don't reccomned that. The 4 inch bore block comes 3.995 and the 4.125 block comes 4.120 bore.
Dart can fully machine a block for you and as far as plate hone they would need to know what you were using for gaskets and hardware to duplicate the end build.
The main lines are line honed from Dart and are in the middle of the spec. That being said 90% of the SHP blocks we machine the customers do step up to a stud kit for 55.00 and from there we do line hone to 2.6415
Here is what we do to an SHP block
On the SHP block when we machine them we do break the main caps down relube and add studs if needed and line hone to the high side of the spec. chamfer theh main cap housing bores and deburr.From there we will deck to your desired deck height, bore the cylinders if needed and hone with a plate using the same hardware and gasket to be used in the end build. We will check lifter bores size as well, tap all oil galley holes deeper, chamfer cam pug hole and freeze plug holes, chamfer head bolt holes. clean and brush out all oil galleys.
Hope this helps
Carl
Belgian1979vette
Well-known member
If i'm not mistaken the std bearings (clevite H) are .095 thick, which would give 2.6415-.095-2.448 = 0.0985 clearance. Looks real big. I though clearance needed to be in the .024 range.
Twin_Turbo
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2 bearing halves!!!! -> .0035
Belgian1979vette
Well-known member
My bad, but still big.
CNC BLOCKS
Well-known member
Lets see here clevite MS-909-H are .0954 your shaft is 2.448
housing bore 2.6415 minus shaft diameter 2.4480= .1935 add shell thickness of both bearings .1908 minus .1935 = .0027 as that should be your oil clearance.
And .0027 oil clearance on the mains is right on the money.
The only problem not to many cranks ground on the low side of the spec.
housing bore 2.6415 minus shaft diameter 2.4480= .1935 add shell thickness of both bearings .1908 minus .1935 = .0027 as that should be your oil clearance.
And .0027 oil clearance on the mains is right on the money.
The only problem not to many cranks ground on the low side of the spec.
Belgian1979vette
Well-known member
Carl,
I take it that all mains are the same size, which would then make it possible to just use one set to get main clearance within spec ?
I take it that all mains are the same size, which would then make it possible to just use one set to get main clearance within spec ?
CNC BLOCKS
Well-known member
Some times you may have to split a set of bearings, We have seen circle track engines with .0018 oil clearance and everything looks fine.
