Getting ready to put a cummins recon head on. How clean should the top of the block be? I have run a scraper over it, didn't really do much. Where the old gasket sat is clean but the area not covered is clean but darker colored.

Just wondering what to do?

 

i would buff it with a power brush

 

Use a Scotchbrite pad to get the surface smooth, then wipe it off afew times with a lint free rag with lacqer thinner on it. Thanks Steve B.

 

Hey junkie iam in the process of doing mine I used a scotch rol lock just chuck it in a drill works real well. Man I feel for you I priced a reman at cummins this morning he quoted $1000 + a few dollars I took the head after stripng it had it magnifluxed and surfaced looks good. I was lucky I guess if you could call it that. Good luck
Cookie

 

Hate to tell you guys, but the engine machine shops love the fellows who use the scotch brite setups on a drill or grinder. They clean very well but they will remove metal more easily than you think.

I sell the machines the shops use to surface blocks and heads and I see it almost everyday. A rigid surfacing machine is capable of taking off as little as .001" and it easily shows up when someone has used a scotchbrite buffer type of cleaner. The problem is it is easy to go from a wide area to a narrow area like between cylinders. It is impossible to keep an even pressure and you wind up removing material and have high and low spots.

A better way to go is with a sanding block or bondo board using 80 or even 36 grit. Stuff rags into the cylinders and block sand the deck with long strokes lengthwise. Same principle as block sanding a car body. Then take a vacuum and clean everything up. You can wipe it down with a good degreaser just before assembly to give the gasket a good purchase. Ask Brian, he'll clue you in.

P.S, I saw your head a few weeks ago, man that thing had some cracks in it! Lots of miles but it must have been working hard. Can you give us some idea of the type of service it has seen? Thanks!

 

I use the pad like I said before with a piece of wood for backing. I've never had any reason for the machine shop guys to love me. But I'm no salesman. Thanks Steve B

 

RT,
So you got to see it? Were u here looking at the new machine Brian got?

I did go over it with an orbital, guess that was not the best. I will do it again with a block and do lengthwise strokes.

Some of the techs @ cummins looked at it. They all said you have her turned up don't you, that's what did it. I replied w/ no it has over 300k on it. I don't know how common those cracks are like the head had but it was pretty much used up.

For service it started out in Arizona pulling trailers for the movie stars to stay while filming out in the desert. Then I got it and used it for my landscaping business in NC for a few years. Then I started hauling horses and that's when I really put on the miles. I went to every state in the lower 48 in my travels over a couple years. In the last 3 years since moving out here it doesn't see many miles unless the weather is bad for my 200 mile roundtrip commute. Sure could of used it the last few days.

 

Yeah, I was there getting the new Serdi head machine up and going. Been doing business with Brian since he started up several years ago. He had another lower mileage 24v head that was cracked as bad or worse than yours!!

About your head, did you have a pyro hooked up during the life of this head? Ever see any egt's? I would guess that with all those towing miles, it got warm a few times. That is what usually leads to cracks like that. Apparently, Cummins perceived a problem and went to an insert type valve seat that should tolerate heat better with the HO motors. Does your new head have seat inserts?

As long as you used a pad with a firm back, kept it flat, and did not get too crazy, you should be fine on the deck. Again, think like a bodyman blocksanding with a long pad. The damage occurs when guys use a fairly flexible pad and spend too much time and pressure in a small area trying to get it bright.

Good luck and let us know how the new head runs!!

 

Head and all is on(new DD2's), fuel lines are on basically everything on the drivers side. Just got my turbo back from HTT was this one mine? Gosh it's clean. Was cleaning and inspecting intercooler boots and found a very tiny hole in the bottom one on the pass side. Darn, that's gonna hold me up. Ordered new bd boots from extreme diesel. Also polished up the airhorn and painted the metal intake tube on the drivers side plus some other items. Got the heat shield fit into place so thats done.

What's left: install manifold and turbo today. install new boots, radiator, hoses (new). Put the belt on and roll her over and adjust valves, fill with antifreeze, prime fuel system and see what happens.

I cleaned all the electrical connections w/ brake clean and applied dielectric grease when reconnecting. I also had to get a new crossover battery cable. I had the radiator cleaned.

I hope nothing leaks.

 

Someone posted on TDR once to never use scotchbrite, said he used to build engines and they had several fail mysteriously. They finally figured out it was caused by using scotchbrite on the block deck. I don't know if there's any truth to that but supposedly the fibers are fine enough to go through the filter but abrasive enough to cause damage. Just food for thought I guess.

When I cleaned my deck I used a razor blade for the most part.

Vaughn