can a 170 block be decked to a zero deck height?

[thefurnacedude]

Hello Everyone,

I have a 200 head with larger combustion chambers going on a 170 block. I would like to end up with about 9.5 - 1 CR. When the pistons in this bock are at TDC, the piston is about .030" from the top of the block.

Can I zero deck this block? I would rather do this than shave the head .090 to keep the CR where I want it.

Please let me know your thoughts as I am sure there are some members have encountered this issue in the past.

Thanks
Tim

 

[Asa]

you can zero deck any block, you just have to pull it and drop it off at a machine shop

 

[Anlushac11]

I thought .020" was normal but it might be .030".

I dont think it would be a problem but your still going to have to do something about losing compression with a new head gasket unless you can find a new steel him head gasket.

Seems like your going to have to mill the head irregardless.

 

[Asa]

i seem to remember something about going just below zero decking to compensate for the headgasket, am i crazy? or just mis-remembering?


also, when you drop it off to be machined, drop it off with the complete rotating assembly so that they can get the most accurate measurement possible for when they deck it

 

[Anlushac11]

i seem to remember something about going just below zero decking to compensate for the headgasket, am i crazy? or just mis-remembering?


also, when you drop it off to be machined, drop it off with the complete rotating assembly so that they can get the most accurate measurement possible for when they deck it

I have heard of guys doing that, so the piston ever so slightly sticks out of the hole.

 

[gb500]

hi read this thread - decked so the pistons stick above the deck by a certain thou.
Not mine !

http://fordsix.com/forum/viewtopic.php? ... highlight=


i,ve decked my 200 block so i have about 8 thou sticking above the deck with an approx 48 thou thick head gasket(aftermarket)
(australian log head)

brett

 

[gb500]

sorry forgot to mention - still need to asemble - so no running feedback yet!
brett

 

[CZLN6]

Howdy Tim and All:

Tim- Yes, but you'll still have to mill the head to attain your CR goal. What Head gasket are you planning to use? Are you using OEM type flat top piston? IF you're using a high lift cam check your valve to piston clearance after all machining.

Brett- Do Aussie 170s use flat-top pistons like USA 170s? Any engine can be decked to zero, and more. Most of posters here have been working with 200s with dished pistons. So If your 170 has flat top pistons and depending on your valve lift, I'd encourage you to do a mock assemble with a piece of clay on top of the pistons to determine valve to piston clearance.

Adios, David

 

[powerband]

I just wanted to mention info that may be useful. The 170 has an advantage in that the thin OEM style - Steel Shim head gaskets are available.

The '63 has a stock '71 170 with a worked D7xx head milled to matcjing @ 48cc chambers (@ .070 ). With steel gasket running @9.5 CR.

Built for modern drivability, MPG and mild performance it uses stock cam, 2Bbl H/W, Dual out headers and OD T5 tranny to original 3.50 rear.

The OD tranny allows the 170's torquey' performance driving through the gears or cruising at Interstate speeds.

The fairly high CR requires Hi-Test but the performance available is worth the price.

Powerband