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Milling deck
https://www.slantsix.org/forum/viewtopic.php?t=64079
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Author:  Charrlie_S [ Thu Sep 19, 2019 2:19 pm ]
Post subject:  Milling deck

What is the most anyone has cut a slant six deck, in particular a 170?

Author:  Charrlie_S [ Sat Sep 21, 2019 5:15 pm ]
Post subject:  Re: Milling deck

No responses? Forget it is a 170 block. What is the most anyone has cut a 225 deck. I bought an abandoned project, awhile back. The PO cut the deck a bunch. Just trying to determine if I should try to salvage the block or junk it.

Author:  Rick Covalt [ Sat Sep 21, 2019 5:55 pm ]
Post subject:  Re: Milling deck

I'm not much help Charlie. I know they have been cut more than my .110 for sure. Do you know how much yours has been cut? Seems like I remember someone cutting .150 but I'm not sure.

Author:  Joshie225 [ Sat Sep 21, 2019 8:30 pm ]
Post subject:  Re: Milling deck

I can't imagine the top of a 170 block being that much thinner than a 225. 0.100" is not too much at all. Do you know how much this one has been cut? Are the pistons out of the holes?

Author:  Dart270 [ Sun Sep 22, 2019 2:18 am ]
Post subject:  Re: Milling deck

No direct experience here, but I guess 0.150-0.200" would be OK. The small bore size works in our favor for rigidity in many places.

Lou

Author:  emsvitil [ Sun Sep 22, 2019 5:22 am ]
Post subject:  Re: Milling deck

Won't the pistons be sticking up out of the block on a 170 if you deck it too much?

Author:  Dart270 [ Sun Sep 22, 2019 7:23 am ]
Post subject:  Re: Milling deck

I bet he is trying to use different comp ht pistons...

Lou

Author:  Charrlie_S [ Sun Sep 22, 2019 7:52 am ]
Post subject:  Re: Milling deck

Back story:
As best I can understand, the PO read about using 2.2 turbo piston in a slant six. But he misunderstood several details. He tried using the 2.2 "turbo" pistons in a 170 engine, with stock 170 crank, rods. Then found out the pistons were too far down the hole, so cut the deck. Don't know why he made the decision to give up on the project, but I wound up getting a smoking deal on all his parts. $100 for everything.
Eight 2.2 turbo pistons std. with rings
Cleaned,bored and honed 170 block
Cleaned 170 crank, did not check journal size, yet.
Six reconditioned 170 rods
New hydraulic "turbo grind" cam and lifters
Cam, rod, main, bearings
Engine gasket set.

Looks like the deck is cut about .150 (measuring with a vernier caliper from deck to main saddle, and compared to a uncut block).
Even if I can't use this block, the other parts are worth much more then the price paid.
I have several 170 and 225 blocks, cranks, rods.
Have a set of 198 rods and ARP bolts
The biggest problem beside the amount of deck cut, is the pistons are the dished pistons, not the flat tops.
Even if I can use this block, it will just be a low compression 170 with better pistons, unless I can cut the head enough to bring the compression back up to between 8, and 8.5 to 1, and use a turbo. Need to measure.

Not sure what would happen, if I use these dished pistons with 198 rods, in a 225 block and crank. Again, need to measure.

Author:  Joshie225 [ Sun Sep 22, 2019 9:05 am ]
Post subject:  Re: Milling deck

Yeesh. That combo of parts would need about a 6" rod and some piston crown work to make it usable as a 170. You could find a 198 crank for that block and then compression distance comes close enough to work with maybe a little off the piston crown.

Author:  Charrlie_S [ Sun Sep 22, 2019 9:49 am ]
Post subject:  Re: Milling deck

Quote:
Yeesh. That combo of parts would need about a 6" rod and some piston crown work to make it usable as a 170. You could find a 198 crank for that block and then compression distance comes close enough to work with maybe a little off the piston crown.
The block already is cut at least .150, so those pistons, 170 rods, and crank, bring the piston close to the stock 170 zero deck. But the pistons are dished, compared to the 170 flat tops, so compression would be lower.

PS: I seem to remember taking some measurements when I first got these parts, and coming up with a cut of about .170 on the block. But I do have a 198 crank on hand.
I really need to do some trial fitting and measuring. Just wanted an opinion on whether the deck was even thick enough, to consider using this block for anything except a boat anchor. Would be a shame, as the condition and machining look nice.

Author:  DadTruck [ Sun Sep 22, 2019 4:24 pm ]
Post subject:  Re: Milling deck

Quote:
the deck was even thick enough, to consider using
trying to make an honest appraisal without any real experience or data is difficult, so in place of having real experience or data with the actual part, use data or experience from something similar.
In this example, consider the aluminum slant six block. It is an open deck block. And it holds up fine to stock HP and driving levels. So I am thinking that if an aluminum block with no upper deck can easily handle 100 hp, a cast iron block with a thin upper deck can do a lot more. Probably the biggest risk is cracking the bore at the upper deck due to the higher combustion pressure in a race engine. But who can really say. Make sure the deck of the block and head have good flatness and a texture to work with the head gasket that you are using, allow for the shortened engagement of the head bolts, and let it rip, like you said, you don't have anything in the block.

Author:  ceej [ Sun Sep 22, 2019 11:47 pm ]
Post subject:  Re: Milling deck

I cut the deck on the Hooptie 0.125", but I think the Jesiolowki deck was cut in the 0.16x range. Don't know if they canted the block to do it. Give Ed a call. I heard this during a conversation at the track or the pit campfire some time ago. I don't think that block had issues with studs/bolts pulling or the head. It threw a rod in the burnout box at Samoa for unrelated reasons. Don't know what his later mills had.

Lots of meat in there for cutting the deck. I could go measure how much on the 170 block in the shop. I believe it to be unmolested.

CJ

Author:  Charrlie_S [ Mon Sep 23, 2019 4:49 am ]
Post subject:  Re: Milling deck

Quote:
I cut the deck on the Hooptie 0.125", but I think the Jesiolowki deck was cut in the 0.16x range. Don't know if they canted the block to do it. Give Ed a call. I heard this during a conversation at the track or the pit campfire some time ago. I don't think that block had issues with studs/bolts pulling or the head. It threw a rod in the burnout box at Samoa for unrelated reasons. Don't know what his later mills had.

Lots of meat in there for cutting the deck. I could go measure how much on the 170 block in the shop. I believe it to be unmolested.

CJ
If you could measure for me, at your convienence, that would be great. Not a big rush, just trying to get my ducks in a row, as far as what parts to use for what.
Could you send me Ed's number in a PM?
Thanks

Author:  Joshie225 [ Mon Sep 23, 2019 10:50 am ]
Post subject:  Re: Milling deck

Quote:
Quote:
Yeesh. That combo of parts would need about a 6" rod and some piston crown work to make it usable as a 170. You could find a 198 crank for that block and then compression distance comes close enough to work with maybe a little off the piston crown.
The block already is cut at least .150, so those pistons, 170 rods, and crank, bring the piston close to the stock 170 zero deck. But the pistons are dished, compared to the 170 flat tops, so compression would be lower.

PS: I seem to remember taking some measurements when I first got these parts, and coming up with a cut of about .170 on the block. But I do have a 198 crank on hand.
I really need to do some trial fitting and measuring. Just wanted an opinion on whether the deck was even thick enough, to consider using this block for anything except a boat anchor. Would be a shame, as the condition and machining look nice.
My calculations included taking a fair bit off the crown of the piston to essentially make the piston a flat top which results in needing a longer rod or a longer stroke. As you have a 198 crank I would explore that route as it's probably less expensive than any other combination of parts to get a workable compression ratio.

Author:  Dart270 [ Mon Sep 23, 2019 12:13 pm ]
Post subject:  Re: Milling deck

198 crank needs some clearance grinding on counterwts and some on the block, but not much. I have mocked this up on one crank and block...

Lou

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