I've received my block, and I'm just about ready to begin cleaning for pre-assembly. I read somewhere that cleaning should be performed without the cam bearings installed. Is this true? Can certain solvents or soap ruin the bearings? Please provide me with all of your block cleaning tips.

Mark

 

Pull all the galley plugs, freeze plugs and of course cam bearings. There has to be a reason for it, since I remember hearing that advice over 30 years ago. Cam bearings should be replaced anytime you do a rebuild so it isn't a real big deal, they are cheap and no sweat for a machine shop to install.
I'd recommend after the block is cleaned to coat the lifter valley and the tops of the heads with Glyptol paint, or Rustoleum Rusty metal primer. I have no proof that this does any good, but I think it looks :cool: .
I assume you are going to get it tanked at a rebuilders or machine shop, make sure that they scrub out all the oil galleys with brushes several times, before final solvent rinse.

 

The reason for the glyptal coating is to leave a smooth non porous surface. The bare casted surface is porous and contaminations will embed in it. Also, the smooth surface retains less oil film and the drainback will be faster.

Have the machining work done on the block first, the shop will remove the bearings. After all machining is done use bristles & lukewarm to warm soapy water and clean the block untill there's no crud left (feel with your fingers), use a pressure washer to speed things up. Don't let the block dry, blow off the water w/ compressed air & spray it with WD40 or light oil.

One hting you can do yourself is use a die grinder to enlarge the drain back holes, this will enable you to remove the sand trap in the drainback hole next to the distributor hole. There will be sand there from casting. Now is the time to remove it.

Marck


[Modified by Twin_Turbo, 12:16 PM 10/30/2002]

 

Sorry...should have stated that the block has already been machined, and the cam bearings are new. I'm just concerned that when I clean the block that I'm going to ruin the bearings, and that crud will build-up behind the bearings.

Mark

 

Mark/81vette:
Strong alkali/basic soaps can etch the cam bearings (& rods & mains brgs) ... some hot tank vats also have a strong alkaline:solvent solution ... some soaps in a bottle are strong alkaline ... the wheel cleaner option at DIY car wash is often strong alkaline.

Was your block vatted/tanked/ pressure washed prior to machinework ... or maybe after the machinework but before cam brg install?

Are your freeze plugs, galley plugs installed yet?

 

When I get mine back I make a hot soapy solution and clean the block like I'm going to eat off it. Get every nnok and cranny then blast it with as much pressure as you can get. Air dry it with a blow gun and then get some WD 40 or similar on the machined surfaces. Then (very important) Start on the bores with a rag with some auto trans fluid on it. Wipe the cylinder many times changing paper towels frequently. Do this until the paper towel shows no more grit or dirt. You will be amazed at what is left on teh walls. This will make the rings seat very fast and very good . Auto trans fluid is designed to suspend dirt in it so it takes the dirt off the walls and keeps it on hte paper towel. Do this with all the bores. You should be ready to assemble after this. I have done this many times and the rings seat very quickly with very little oil blow by on start up.

 

Here is what's been done to the block before I purchased.

Select casting that shows very little core shift. Cylinder walls sonic tested for thickness. Block burned to remove imperfections and shotblasted to totally clean to bare cast iron and for added strength. Block decked 90 degrees parallel to crankshaft centerline with professional BHJ fixture. bored .030" and race honed with BHJ torque plate to finish size of 4.1555" Deck restrictors installed to add strength to the deck. ARP main studs installed and then rear seal surface bored and all mains align honed on Sunnen equiptment. Lifter valley oil returns deburred and grooved for improved oiling. Lifter valley return holes tapped for restrictors if desired. Rear Main cap has been polished and enlarged where the oil flow occurs. Brass freeze plugs installed and all cam bearings and plugs installed.

I need to have the bores honed again anyway for the forged pistons, as the 4.1555 bore does not give enough piston to side wall clearance. I talked with a machine shop in my area today, and what he suggested is that I go ahead and clean it as good as I can with the bearings/freeze plugs installed. Then preassemble the engine to check deck height and other clearances. Then take it to them for final machining. At this point I would imagine the bearings and plugs will need to be replaced. So I'll have them clean it before putting the new cam bearings and plugs in. Does this sound like the right order and procedure to do this?

Mark

 

Gordonm,

When you get your block back does it already have the cam bearings and freeze plugs installed? If so, do you think the cam bearings would trap anything in the grooves behind the bearings while your cleaning? Are you using any solvents that would ruin the bearings? Maybe I'm worring to much, but I want to do this right.

Mark


[Modified by 81vette, 6:44 PM 10/30/2002]

 

Mark/81vette:
Sounds like you got that block outa FL ... good score! I'd considered the group but decided 230cc runners weren't practical for my street use. Sounds like you have the preassemble-clean-cam brg sequence in-hand ... but triple check one more thing ... closely mike your pistons & bore ... you may be there already ... most STREET forged will clear OK @ 0.005 ... more for race ... sometimes it's a judgement call. G'Luck!

 

Yes, but I did not get the heads. I plan to use AFR 210's on this build.

I read the SRP instructions, and it says the clearance of .002-.0025 is already built into the pistons. However, the pistons mic at 4.154 which only gives a .0015 clearance if the bores infact are 4.1555. I'm waiting on a dial bore gauge to check the cylinders before I go any further. I'm also waiting to get the standards for the mics that I borrowed from a friend. The mic may need adjusting.

Mark

 

Mark:
In this case you’re reasonably assured the bore is round & not egged. Unless all gages-tools (od mike, bore gage, standards) have been recently professionally calibrated with repeatability verified ... you might be better off in this case to skip the bore gage & instead use a simple telescoping gage along with your mike. This would eliminate any possible tolerance stackup between mike & a bore gage. This way you’d be (more) directly measuring difference between od piston-id block. Just a suggestion.


[Modified by jackson, 11:39 AM 10/31/2002]


[Modified by jackson, 11:40 AM 10/31/2002]

 

The cam bearings are installed but no freeze plugs. I just use mild soapy hot water and it does the trick. I wash it many times and then finally air dry it. Soap is not going to hurt the cam bearings :yesnod:

 

Thanks for the suggestions Jackson.

Gordon, what soap are you using? I'm going to start this weekend on the cleaning.

Below are my piston measurements. According to SRP the acceptable street range is .002-.0025 for these high silcon 'forged' pistons. Doesn't this seem tight for a forged piston? I thought forged pistons needed .003-.004 clearance, or is that for racing?

They all fall within an acceptable range except the 4.1540 piston. I haven't measured the bores yet, but I assume there will be enough deviation in the bore sizes to allow me to mix and match the pistons/bores for the best fit. The ideal situation would have been to give the original machine shop the pistons before boring/honing, but I didn't have that luxury. What do you guys think about the range of piston sizes, is this a typical spread for 8 pistons?

4.1532
4.1527
4.1526
4.1540
4.1534
4.1533
4.1533
4.1533