HEMI rebuild
#2697666
09/15/19 06:47 AM
09/15/19 06:47 AM
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Joined: Mar 2010
Posts: 984 Tennessee
Hemi ragtop
OP
super stock
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OP
super stock
Joined: Mar 2010
Posts: 984
Tennessee
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Last year I pulled the 540 cid HEMI out of the Coronet to find the excessive oil consumption. I’m glad I did. I had used a well known shop for the build. For some reason, my engine must have been worked on only on Mondays after a long weekend! They had built several engines for magazines, and friends. I expected professional results. Instead I had the following:
The block was delivered already bored and honed for the 4032 alloy Diamond coated pistons. It appeared as though the shop didn’t like the tight clearance that Diamond recommends for these pistons and so the bores were opened up to TWICE the recommended clearance. To make matters worse, the tools used did not provide the proper finish. Indeed, much of the wall surface showed NO crosshatch!
I had pre assembled the engine (new parts) and determined that the deck needed to be cut .040” Instead it had been cut .090” causing witness marks where the pistons had been contacting the heads!
The valve to guide clearance was as much as .007” vs .0015”. This shop either didn’t posses measuring instruments or didn’t know how to use them! I found out after the fact that they didn’t own torque plates for a HEMI. They evidently didn't have the correct honing stones for a Mega Block either!
The list goes on. Had I not pulled the engine, it would have had a short life.
After talking to several people I chose Bob Meyer at Performance Automotive in Greenville TN. Bob worked on Allen Johnson’s Pro Stock engines. He not only had a torque plate but a fixture to properly locate the bore center for honing!
Bob corrected all the problems and sent me these photos. He also ported the MP heads. I can’t wait to see the results on his Dyno in the near future!
Last edited by Hemi ragtop; 09/15/19 06:50 AM. Reason: Misspelled word
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Re: HEMI rebuild
[Re: Hemi ragtop]
#2697848
09/15/19 07:47 PM
09/15/19 07:47 PM
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Joined: Oct 2007
Posts: 4,212 New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,212
New York
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100 years ago, a famous MoPar racer and author had a famous shop build him a B stroker engine, for a car to be raced immediately. He assumed that everything had been checked...
The crank would not make a full revolution.
Boffin Emeritus
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Re: HEMI rebuild
[Re: polyspheric]
#2697868
09/15/19 08:45 PM
09/15/19 08:45 PM
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Joined: Jan 2011
Posts: 4,785 Utah and Alaska
astjp2
master
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master
Joined: Jan 2011
Posts: 4,785
Utah and Alaska
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I did my own assembly, but the machine work was done by a local machine shop, I think I will have one problem with a rod bushing, I may have to tear the engine down and hone it out if there is a problem. We also didnt put valve seals on the exhausts, I think that may also be a problem...Time will tell if I screwed the pooch on my 572 hemi...I feel your pain. Tim
1941 Taylorcraft 1968 Charger 1994 Wrangler 1998 Wrangler 2008 Kia Rio 2017 Jetta
I didn't do 4 years and 9 months of Graduate School to be called Mister!
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Re: HEMI rebuild
[Re: astjp2]
#2697894
09/15/19 09:29 PM
09/15/19 09:29 PM
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Joined: Jan 2003
Posts: 17,926 Akron, Ohio
ProSport
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 17,926
Akron, Ohio
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That sucks, I'm glad it's getting fixed. And your car is gorgeous!
1970 Challenger, all aluminum 528 Hemi, HDK suspension, Tremec 5 speed manual
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Re: HEMI rebuild
[Re: ProSport]
#2697947
09/16/19 05:50 AM
09/16/19 05:50 AM
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Joined: Mar 2010
Posts: 984 Tennessee
Hemi ragtop
OP
super stock
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OP
super stock
Joined: Mar 2010
Posts: 984
Tennessee
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That sucks, I'm glad it's getting fixed. And your car is gorgeous! Thanks and your car is impressively fast for a true street car! Driving the car is what I enjoy, but having a car that you can really drive that also runs deep into the 10s is like having your cake and eating it too!
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Re: HEMI rebuild
[Re: astjp2]
#2698324
09/17/19 09:03 AM
09/17/19 09:03 AM
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Joined: Jan 2003
Posts: 13,400 Marion, South Carolina [><]
an8sec70cuda
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 13,400
Marion, South Carolina [><]
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Hemi ragtop...hope it works out better for you this time!
astjp2...FWIW, I haven't run exhaust valve seals on my hemi for a long time w/ no issues. I know every setup is different though.
CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 18 spline 4 speed, Dana 60 '71 Demon, 340, low gear 904, 8.75 '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax
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Re: HEMI rebuild
[Re: Hemi ragtop]
#2698363
09/17/19 10:03 AM
09/17/19 10:03 AM
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Joined: Jan 2003
Posts: 17,912 S.E. Michigan
ZIPPY
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 17,912
S.E. Michigan
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Nice to hear all the issues were found and are being fixed. You should be set for a long time afterwards!
Rich H.
Esse Quam Videri
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