Rough block deck...

connormcd88MKIII · 04-04-2010, 10:17 PM

Now I have a picture of my number six cylinder and it seems to be slightly roughed up. It seems minor but I want to make sure that there wont be a leak. Do you guys think it will be a problem? What are my possible solutions?[IMG]P4030699.JPG[/IMG]

cre · 04-05-2010, 01:18 AM

I'd get the block machined.

Green7mgte · 04-05-2010, 02:17 AM

cre, can you say why you recommend machining the block? what from the picture did you discern, that warranted machining.

just curious.
thanks.

cre · 04-05-2010, 05:12 AM

Always hard to tell from a picture, but the erosion between the cylinder bore and the water jacket are enough to stop me from just slapping it all back together. Overall though the surface isn't clean enough IMO, the indentions from the rings, the pits from the former HG, scratches.... and so on.

Connor, were you loosing coolant or did the coolant have an excessively high pH before you pulled the head off or before the HG blew (if it did ever blow in a big way)? As clean as that piston is compared to #5 it's been seeing a fair amount of water.

connormcd88MKIII · 04-05-2010, 06:30 AM

I was losing coolant... Heres also a picture of the old head gasket. And if I were to get it resurfaced to correct the pitting, would I need to make any modifications to the pistons, rods, bearings etc., to account for the loss of the material for the block?

MA70-3.0GT · 04-08-2010, 03:58 PM

Sorry to say this, but as far as I can tell from the pic what appears to have happened is the previous HG (guessing it was done fairly recently) went in the same area & somebody was a bit over zealous with the cleanup of the affected area. TBH it looks from the photo as if it's been hit with fairly heavy sandpaper or wire wool... And then the resulting block warpage has given the effect we see here with the next HG.

I'd have to agree with cre that machining is the only sure way to make sure it's within warpage tolerance, the head may also need skimming now if that's in a similar state. As to modifications after a skim, it depends on how much material is removed & I can't think of the specs off hand but it's in the tsrm anyway & if both head & block come within the tolerances after skimming then you don't need to do a thing.

However if (as usual, as the factory tolerances are tight-ish) there is too much material gone for a stock HG you can go for a thicker metal HG to take up the difference, you'll need to look into head/deck finishes for that route though as they have to be mirror like... IMO best have the pair finished to MHG surface roughness specs from the get go & then if you find you can get away with a stock item (if you really wanna by then!) fair enough, but if not you're not stuck then with running back to the machine shop for more sessions & more material/not to mention cash, lost...

connormcd88MKIII · 05-23-2010, 04:28 PM

So I finally finished working yesterday and it was time to attempt to start it. It started up after only a couple of seconds and it seemed fine. Then I noticed a a bit of white smoke coming from where the exhaust manifold meets the exhaust. Any ideas on what may be the problem?

Green7mgte · 05-24-2010, 02:09 AM

did you strip any of the exhaust bolts?

04-04-2010, 10:17 PM	#1
connormcd88MKIII Stock Join Date: Mar 2010 Location: Mineola, NY Posts: 5	Rough block deck... Now I have a picture of my number six cylinder and it seems to be slightly roughed up. It seems minor but I want to make sure that there wont be a leak. Do you guys think it will be a problem? What are my possible solutions?[IMG]P4030699.JPG[/IMG] Attached Thumbnails

04-05-2010, 01:18 AM	#2
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	I'd get the block machined. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

04-05-2010, 02:17 AM	#3
Green7mgte Supra Forum Moderator Join Date: Nov 2009 Location: Green-Ohio Posts: 1,297	cre, can you say why you recommend machining the block? what from the picture did you discern, that warranted machining. just curious. thanks. __________________ 92 Ma71 7mGTE Auto. SafcII Supra FAQ Supra MKIII FAQ Classified Section guidelines :

04-05-2010, 05:12 AM	#4
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Always hard to tell from a picture, but the erosion between the cylinder bore and the water jacket are enough to stop me from just slapping it all back together. Overall though the surface isn't clean enough IMO, the indentions from the rings, the pits from the former HG, scratches.... and so on. Connor, were you loosing coolant or did the coolant have an excessively high pH before you pulled the head off or before the HG blew (if it did ever blow in a big way)? As clean as that piston is compared to #5 it's been seeing a fair amount of water. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

04-08-2010, 03:58 PM	#6
MA70-3.0GT 12psi boost Join Date: Oct 2009 Location: Crewe, England Posts: 356	Sorry to say this, but as far as I can tell from the pic what appears to have happened is the previous HG (guessing it was done fairly recently) went in the same area & somebody was a bit over zealous with the cleanup of the affected area. TBH it looks from the photo as if it's been hit with fairly heavy sandpaper or wire wool... And then the resulting block warpage has given the effect we see here with the next HG. I'd have to agree with cre that machining is the only sure way to make sure it's within warpage tolerance, the head may also need skimming now if that's in a similar state. As to modifications after a skim, it depends on how much material is removed & I can't think of the specs off hand but it's in the tsrm anyway & if both head & block come within the tolerances after skimming then you don't need to do a thing. However if (as usual, as the factory tolerances are tight-ish) there is too much material gone for a stock HG you can go for a thicker metal HG to take up the difference, you'll need to look into head/deck finishes for that route though as they have to be mirror like... IMO best have the pair finished to MHG surface roughness specs from the get go & then if you find you can get away with a stock item (if you really wanna by then!) fair enough, but if not you're not stuck then with running back to the machine shop for more sessions & more material/not to mention cash, lost... __________________ '89 MA70 Supra GT aero 3.0turbo JDM, Rebuilt motor, K&N intake, 3" stainless turbo-back. New turbo and braided line kit... '89 Honda NC27 400, NC23 cams, open pipe, PC36a shock & possibly Showa USD forks... '83 Yamaha 29R XJ750E-II, number 69 off the line, only runner in the country? Original except Koni shocks '95 Honda PC26 CB500R, Winter hack, hateful, trying to sell it I'm not paranoid, they really ARE after me!!!

04-05-2010, 06:30 AM	#5
connormcd88MKIII Stock Join Date: Mar 2010 Location: Mineola, NY Posts: 5	I was losing coolant... Heres also a picture of the old head gasket. And if I were to get it resurfaced to correct the pitting, would I need to make any modifications to the pistons, rods, bearings etc., to account for the loss of the material for the block? Attached Thumbnails Last edited by connormcd88MKIII; 04-05-2010 at 10:18 PM.

05-23-2010, 04:28 PM	#7
connormcd88MKIII Stock Join Date: Mar 2010 Location: Mineola, NY Posts: 5	starting it up So I finally finished working yesterday and it was time to attempt to start it. It started up after only a couple of seconds and it seemed fine. Then I noticed a a bit of white smoke coming from where the exhaust manifold meets the exhaust. Any ideas on what may be the problem?

05-24-2010, 02:09 AM	#8
Green7mgte Supra Forum Moderator Join Date: Nov 2009 Location: Green-Ohio Posts: 1,297	did you strip any of the exhaust bolts? __________________ 92 Ma71 7mGTE Auto. SafcII Supra FAQ Supra MKIII FAQ Classified Section guidelines :

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
HELP!: 7MGTE engine block info needed	barton	MKIII Supra	1	05-19-2010 05:54 PM
HELP!: 7MGTE engine block info needed	barton	MKIII Supra	6	04-14-2010 09:28 PM
decking block, reuse most parts.	jvginpdx	MKIII Supra	0	08-18-2009 07:03 PM
prepping block for headgasket question	dannydavi	MKIII Supra	1	12-06-2008 07:44 AM