Sand Suface Rust on block with WD40???

joshtexican · 05-17-2010, 04:09 PM

Hey does anyone know if I am allowed to 800grit lightly sand some surface rust of the block?

I am about to put the mhg on and didn't know if that was going to be an issue once the head is torqued down. The motor is on an engine stand and it had been sitting while I was waiting on some parts. I heard I can clean the internals with wd40 and blowing with air. Does that mean I can spray the cylinders and pistons to lube and clean as well, with wd40??

Your help will be greatly appreciated!!

supraflymkiii · 05-18-2010, 02:01 AM

If youre going to use air to clean stuff out do your cleaning first then blow it out but if you use wd40 then try to blow it out its not going to work because the shit will be stuck in the wd40. I wouldn't recommend using wd40 as lube for assembly but it will be good to keep stuff from rusting. If you're going to put a mhg on your engine and its out of the car you might as well have it decked so its perfectly smooth. it will save you time and money in the long run.

joshtexican · 05-18-2010, 04:47 AM

The motor is just about fully built internally. The block has been resurfaced along with the head. Bored Forged pistons, eagle rods, arp supporting hardware, and rebuilt head. The thing is the block has been sitting and has some surface rust on it now. Its light rust, thats why I was asking if I can use wd40 and sand with a extra thin sand paper.

By saying using wd40 to lube I meant, Can I use it to clean the little trash in the motor. After that just spray to keep it somewhat lubed and also so it wouldn't rust. Or shall I say "If it isnt a problem to spray the internals with wd40 and leave it there"

I have never built anything and needed some help to see if it was safe to do so. But I really appreciate it, just trying to clarify things.

Thanks for the reply bro

MA70-3.0GT · 05-19-2010, 02:23 PM

I'd say for MHG purposes you likely need to get the block refinished now as the surface roughness tolerances are in the single microns range i.e. you need pretty much a mirror finish for it to work properly. For fitting a stock HG I was advised that it was possible to lightly sand the deck surface to remove crap but that it was to be done evenly if at all & not in any one area, using a piece of plate glass as opposed to a block & with at least 1200/1500 grit paper, anything lighter if available.

I don't know how much surface rust there is though but if you're thinking in terms of 800 grit paper I'd imagine theres enough surface damage to warrant refinishing now if only for your peace of mind... If you do end up sanding after all then I'd say WD40 is fine as a lubricant as that's what I used, but do bear in mind that was still only for a composite HG.

FRISBEE · 05-19-2010, 05:51 PM

use a scotch pad and some wd40 to remove the surface rust, just like what your mom has on her sink. spray some brake clean after and blow it dry after. WD40 works gret to coat the block for storage.

joshtexican · 05-19-2010, 07:25 PM

Thanks for the info I already sanded the surface with the paper and the scotch pad actually!! It turned out great seeing how it was already resurfaced when the pistons were put in and the head was shaved.

Thanks a lot again for the info. I will be putting the head on the block within the next few days (my schedule is a little wack)

Any tips I need to know before I put the head on block? ANything like any other random parts that need to be on?

05-17-2010, 04:09 PM	#1
joshtexican 3" Exhaust Join Date: Apr 2010 Location: NC Posts: 136	Sand Suface Rust on block with WD40??? Hey does anyone know if I am allowed to 800grit lightly sand some surface rust of the block? I am about to put the mhg on and didn't know if that was going to be an issue once the head is torqued down. The motor is on an engine stand and it had been sitting while I was waiting on some parts. I heard I can clean the internals with wd40 and blowing with air. Does that mean I can spray the cylinders and pistons to lube and clean as well, with wd40?? Your help will be greatly appreciated!!

05-19-2010, 02:23 PM	#4
MA70-3.0GT 12psi boost Join Date: Oct 2009 Location: Crewe, England Posts: 356	I'd say for MHG purposes you likely need to get the block refinished now as the surface roughness tolerances are in the single microns range i.e. you need pretty much a mirror finish for it to work properly. For fitting a stock HG I was advised that it was possible to lightly sand the deck surface to remove crap but that it was to be done evenly if at all & not in any one area, using a piece of plate glass as opposed to a block & with at least 1200/1500 grit paper, anything lighter if available. I don't know how much surface rust there is though but if you're thinking in terms of 800 grit paper I'd imagine theres enough surface damage to warrant refinishing now if only for your peace of mind... If you do end up sanding after all then I'd say WD40 is fine as a lubricant as that's what I used, but do bear in mind that was still only for a composite HG. __________________ '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!!!

05-19-2010, 05:51 PM	#5
FRISBEE Intake Join Date: May 2010 Location: Albuquerque, New Mexico Posts: 49	use a scotch pad and some wd40 to remove the surface rust, just like what your mom has on her sink. spray some brake clean after and blow it dry after. WD40 works gret to coat the block for storage. __________________ 1991 Toyota Supra 580rwhp617TQ 11.80@117MPH Under Construction 1992 Honda Prelude 400Hp ??TQ 14.0@ 114MPH Time for Update 2007 Cadilliac Escalade daily Knowledge Is Power...................

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

05-18-2010, 02:01 AM	#2
supraflymkiii 3" Exhaust Join Date: Sep 2005 Location: Menasha, WI Posts: 63	If youre going to use air to clean stuff out do your cleaning first then blow it out but if you use wd40 then try to blow it out its not going to work because the shit will be stuck in the wd40. I wouldn't recommend using wd40 as lube for assembly but it will be good to keep stuff from rusting. If you're going to put a mhg on your engine and its out of the car you might as well have it decked so its perfectly smooth. it will save you time and money in the long run.

05-18-2010, 04:47 AM	#3
joshtexican 3" Exhaust Join Date: Apr 2010 Location: NC Posts: 136	The motor is just about fully built internally. The block has been resurfaced along with the head. Bored Forged pistons, eagle rods, arp supporting hardware, and rebuilt head. The thing is the block has been sitting and has some surface rust on it now. Its light rust, thats why I was asking if I can use wd40 and sand with a extra thin sand paper. By saying using wd40 to lube I meant, Can I use it to clean the little trash in the motor. After that just spray to keep it somewhat lubed and also so it wouldn't rust. Or shall I say "If it isnt a problem to spray the internals with wd40 and leave it there" I have never built anything and needed some help to see if it was safe to do so. But I really appreciate it, just trying to clarify things. Thanks for the reply bro

05-19-2010, 07:25 PM	#6
joshtexican 3" Exhaust Join Date: Apr 2010 Location: NC Posts: 136	Thanks for the info I already sanded the surface with the paper and the scotch pad actually!! It turned out great seeing how it was already resurfaced when the pistons were put in and the head was shaved. Thanks a lot again for the info. I will be putting the head on the block within the next few days (my schedule is a little wack) Any tips I need to know before I put the head on block? ANything like any other random parts that need to be on?