The Stovebolt Site Forums The Shop Area Engine Shop Installing new cylinder head

I'm getting ready to install a rebuilt cylinder head on my truck's 235 and I was reading page 6-8 in the 1948 to 1951 Chevrolet truck shop manual. In the cleaning paragraph it recommends cleaning carbon deposits from pistons and cylinders. Any thoughts on the best way to do this? Also does anybody know the actual weight of the block with internals installed? I have a block that I want to ship and I'm researching the best way to do that also!

Thanks for your thoughts!

I usually use a dull pocket knife, or the like to scrape the tops of the pistons. Aluminum is pretty soft.

I think the block with no head would be around 600 pounds?

I'm sure someone will know with more precision.

Christopher,

Thanks for the reply. I'll start gently scraping tommorow and get it cleaned up as much as possible before I put on the new head. The old one was cracked in two places and a few pistons got pretty gummed up so I didn't want that old carbon residue going into the new head.

The dry weight of a complete 235 w/ clutch is 613 lbs. If you have a head you can weigh it and adjust accordingly.

I shipped a head out for repair with the valves still in it and UPS weighed it in around 90 pounds.

Thanks again for the input! Any more thoughts on cleaning the top of the cylinders? Besides scraping carbon off should I wipe everything down with a cleaner or solvent? Also, any thoughts on break-in of a new head?

I use a wire brush on a die grinder.

Thanks Builder, your input is appreciated. I've read many of your posts and learned alot! Now another question...to get each piston to TDC so I can clean it (engine installed in truck) do I turn the motor over with a tap on the starter or is it possible to turn the crankshaft from the front of the engine with the radiator installed?

I like to use kerosene to clean things up afterwards, and then I usually put a little marvel mystery oil over the clean parts. I find the mystery oil makes scraping the carbon a little easier too. I also like the way it smells!

You can easily turn the engine over by hand using the fan belt, with the trans in neutral.

You'll want to spray your new head gasket with that copper spray sold for just this purpose.

Once the head is back on the truck, you'll want to use an oil can and oil all the rockers, pushrods, valves, etc so they aren't dry on startup.

As for break in, the manual covers this I think. If I recall, you put 'er back together, set the valve lash at the loose end, then warm up the truck to operating temperature and let it cool down, then re check the torque on the head bolts. Then warm the truck up to operating temperature, and reset the valve lash.

It might be worth taking a look into the rocker arm tube, and making sure there is no sludge in there, if the head has been rebuilt, it should be clean, but you never know... On a previous truck I owned, a local machine shop had rebuilt the head just before I bought the truck, and the tube was full of sludge still, it hadn't been cleaned out!

Be sure to oil the head bolts, both threads and under the head so you get a accurate torque reading, dry bolts don't tighten the same as lubed ones. If you have a cylinder hone, you can run the pistons to the bottom and hit the cylinders a little with the hone, not much, just enough to scratch them a little. Use a good solvent of your choice and wipe the cylinder walls and piston tops when you are done cleaning. I have taken a propane torch and hit the carbon build up to cook it off. Once its been heated it comes off really easy, then scotch brite pads and solvent (mineral spirits).

Joe

Joe and Christopher, Thanks! I think I can start this pretty well prepared now. I also did a google search within Stovebolt on installing copper head gaskets and found a very useful thread there.

From a Rookie...Thanks!

Do not hone cylinders with pistons in place, You will fill the pistons and rings with metal residue. This will act as a grinding compound on your cylinders and pistons.

I have honed many a cylinder with pistons in place. Its more of a roughing up then honing, just a few laps around is all it takes. Maybe I have been lucky all these years, but I have not seen any problems. I figure all the turbulance from compression and explosion blows any remains out the exhaust.

If you feel this not something you prefer not to try, by all means don't, we all got opinions and are free to choose which ones we believe. I have done a lot of stuff over the years that you are not suppose to do, some worked some didn't.

Joe

Hey guys, thanks again for your input!

Joe, that is one sweeeeet truck! After I get this done I need to post some pictures of my '51 on my page....someday!