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~~james_dunn~~ · 03-12-2021, **(Subject: Cylinder block deck height )**

Running into issues putting together an engine. Machine shop is saying minimum deck height is 17.016" i have multiple block that have all been decked from various machine shops, they are all basically below the minimum deck height @ 17.010. That being said, deck height being to low obviously raises compression, to low it back down you run a thicker head gasket. But i don't know of any thicker head gaskets offered for the DOHC series ISX. also you have to consider this will move the liner closer to the crank so will effect the top piston ring to anti polish ring clearances, regardless of liner protrusion. Question..... what is the factory deck height of the ISX block? cummins can't tell me. Also has anyone assembled an engine with this low of deck height and if so where did you get a thicker headgasket.

Rawze · 03-13-2021, **(Subject: Cylinder block deck height )**

Every single time I have seen people lower the deck height on an ISX... it ended in disaster and the engine lived a short life due to significantly higher than normal compression ratios and all sorts of other ill-effects. They are not designed for such mods.. and frankly there is no reason whatsoever to machine the top deck of one for ANY REASON outside of someone causing some sort of damage to one out of stupidity!

OUTSIDE OF SOME SERIOUSLY RARE-AS-HELL CIRCUMSTANCES ... LIKE SOMEONE CAUSING DAMAGE TO THE TOP DECK BECAUSE THEY WERE AN IDIOT!!!... WHY THE H#ELL WOULD SOMEONE WANT TO MACHINE THE TOP OF THE DECK ON AN ISX BLOCK IS BEYOND ME TO BEGIN WITH!!-- THERE is NO ADVANTAGE TO DOING THIS WHATSOEVER!!! --- WTF IS SOMEONE THINKING!?

IT AIN'T NO GODDAMN OLD-SCHOOL GARBAGE-CAN DESIGNED ENGINE!... STOP TRYING TO MACHINE THE TOP DECKS OF AN ISX! .. IF IT IS THAT DAMAGED BECAUSE OF SOME COMPLETE MORON'S MISTAKES!!1... THROW THE BLOCK AWAY!

====

AND IF YOUR SHOP is machining ISX top decks as part of come common horrible practice due to some twisted reality of lunacy -- THEN I WILL BE THE FIRST ONE TO TELL EVERYONE ON THIS FORUM TO RUN AS FAST AS THEY CAN AWAY FROM YOUR SHOP!!! -- YOU ARE OBVIOUSLY DOING SOMETHING VERY VERY WRONG!!!

next, he will be bragging how he has the old heads off ISX's re-machined too... I shutter to think of what other horrible things that some places out there will do to these engines.

If your looking for support on garbage mods and horrible practices like that ... your on the wrong forum!.

hhow55 · 03-13-2021, **(Subject: Cylinder block deck height )**

I recall a guy taking an isx head to machine shop in Houston, and they wouldn't touch it.
They said get one from cummins

~~james_dunn~~ · 03-15-2021, **(Subject: Cylinder block deck height )**

(03-13-2021 )Rawze Wrote: Every single time I have seen people lower the deck height on an ISX...

Thank you for your answer, however i guess i miss represented what i'm doing. I understand all the negatives that go alone with decking the ISX blocks and am truely shocked that i have received 4 blocks from multiple sources all over the country that have this same issue, so i was simply inquiring if i was missing something, the customer i'm building this engine for traveled hundereds of miles because i build very reliable engines and leave no stone unturned. I was simply asking about deck height because i know all the horrible things that arise from increasing compression, ect, ect, ect. That result from deck height changes. I am really disturbed that this seems to be a super common issue apparently with machine shops doing this to blocks. I am currently trying to make due with used blocks because of the current availability issues with cummins for a new block. Ive been told up to 200days out for a new block. I will continue serching for a new block but was completely baffled by the common malpractice, the machine shop that i use checked block height at my request because it is very obviously been decked and they advised it was below the minimum, on all 4 blocks i have received from various used block suppliers. I know cummins states something like .003" is the maximum allowable deck removal amount, but yes i agree i have no idea why an ISX nwould need to be decked in the first place.Looks to me what machine shops are doing is decking the block to "restore" liner height vs cutting and shimming the liners like normal. I have no idea why this is happening widespread. I have several engine that have counterbores cut to the max and running several shims with higher mid 700HP on 60-65psi boost for over 600K miles without issue so why these blocks are being decked is beyond me. I was simply asking if i was missing something that had changed with parts availability that i wasn't aware of, thinking maybe some unknown was why all these blocks are getting decked to the point of being ruined. Your answer confirms my fears, people are idiots when it comes to making a buck and these machines shops are doing just that. decking blocks to make them appear nice and good hoping the people using these blocks are too stupid to measure things themselves.

tree98 · 03-15-2021, **(Subject: Cylinder block deck height )**

james_dunn
[/quote' Wrote: I have several engine that have counterbores cut to the max and running several shims with higher mid 700HP on 60-65psi boost for over 600K miles without issue

You must not be referring to an isx with that statement. It's well known that they won't hold up very long with that amount of boost before it will crack the head or a piston.700 hp wouldn't require boost anywhere near that level anyway.

Rawze · 03-15-2021, **(Subject: Cylinder block deck height )**

(03-15-2021 )james_dunn Wrote: ...
higher mid 700HP on 60-65psi boost
...

THIS GUY SOUNDS LIKE ONE OF THOSE PEE-DEE-EYE STYLE ENGINE KILLING IDIOTS FOR SURE! - I SUSPECTED AS SUCH ON THEIR FIRST POST... WHY I WAS A BIT HARSH... BUT NOW HE PROVES BEYOND ANY SHADOW OF ANY DOUBT IT ALL ONTO HIMSELF.

--- YUP ... THERE IS A MORON AROUND EVERY CORNER WITH THESE ISX ENGINE,... AND YOU ARE CLEARLY ONE OF THEM!

this guy is a complete engine killing butcher!!! -- BANNED!

TAKE YOUR ENGINE KILLING BRAGGING, BAD DELETE, OVER-BOOSTING LUNACY PRACTICES BACK TO SOCIAL MEDAI WHERE ALL THE OTHER ISX IDIOTS HANG OUT. -- YOU KNOW... THOSE PLACES THAT TRADE BAD INFORMATION, PIRATE 'JAIL-BREAK' SOFTWARE, DO BAD DELETE PROGRAMMING, DO THOSE MORON TURBO SWAPS, AND ALL THE OTHER HORRIBLE IDEAS ... WHERE THAT STUFF BELONGS!