302 Chevrolet Engine Build

[MIKE JONES 302]

Originally Posted by Nmbr1GMfan

Looking good son, keep it up.

Thank you

I bored the block, had to go 4.034 to get it to clean up. Next I will deburr the deck and bottom of the bores, and relieve the bottom of the bores for honing over stroke, from there it will be honed to 4.040. The balancing will be done after the block is done.

[Greg Reimer 7376]

That disparity you mentioned on the dimensions regarding the block decks isn't unheard of. Many moons ago, I built a 283 for a car I had. The block line honed fairly well, but I had .050" deck height on the right head. It was consistent from cylinder #2 through cylinder #8. I brought it down to be correct with whatever steel head gasket we all used at the time.The left deck was .050" for cylinder # 1,but it rapidly shrank as I measured back until i had .025" on the outer wall of cylinder #7, but the portion of the deck closest to the lifter valley at cylinder#7 had only about .022". That head obviously slanted downhill front to rear, and was twisted as well. The good thing about '60's blocks is that they are all real seasoned by now and aren't going to move any more now. I got hold of an original unrebuilt block wiith factory stampings visible on the right front of the deck,and it had a final assembly date of about May the 15th of 1967. The cast date on the rear of the block indicated it was cast May 12. Hardly a seasoned casting.I didn't rebuild it, it got sold or traded off, but I wonder how accurate the machining at the engine plant could have been,especially when it hardly cooled off from the foundry. Your attention to detail on this project is refreshing to see!

[Rich Biebel]

I did block and head machine work for years. Milled blocks square on a Storm Vulcan 85B and used a Kwik Way FN boring bar directly on the block decks. That was pretty common going back many years before better equipment and fixturing came along. I counterbored the bottom of any blocks that had webbing that would interfere with honing stones. I offset the boring bar and used it to machine the web back from the cylinder bore at the bottom. Milling stock blocks I often found them twisted side to side. Right front up a little, left front down a little and opposite at the rear of the block. I would be happy as a pig in you know what if I had those machines and spent all day everyday doing that work as I did 30 years ago. Milled and bore blocks at the same time. Radio playing and smokin a cig . Lol Throw in some heads and rods and just about everything else done in an engine shop. The work I loved to do most. Machine and build engines.

[MIKE JONES 302]

The crank has been ground .010.010 and indexed with the stroke set at 3.00. Balancing next.

[Larry Hill]

I'm always willing to learn. What was the reason to have the honing oil shut of on #2,3,4 mains when line honing the block when the oil pump was on # 5 main on post 17? How much did it move the crank center line toward the cam centerline?

Thanks for sharing on such a classic build.

[MIKE JONES 302]

Originally Posted by Larry Hill

I'm always willing to learn. What was the reason to have the honing oil shut of on #2,3,4 mains when line honing the block when the oil pump was on # 5 main on post 17? How much did it move the crank center line toward the cam centerline?

Thanks for sharing on such a classic build.

The number 2 3 4 mains hone faster than the number 1 and 5, I turned the oil off to break the hone stones down more on the middle of the mandrel. Not sure on how much the center line was moved, but I cut the caps .003 on 1 and 5 and .005 on the 2 3 4 main caps.

[Greg Reimer 7376]

Back in the days of my vocational training, we bored several blocks in our auto shop class using a boring bar that sat on the deck and affixed itself directly to the block. Now, realizing how inaccurate the deck surfaces are on most blocks, and that the further you move away from the point of origin of a machining operation the further away from true center you get, how far off those cylinders must have been when finished from the true blueprint specs of those engines. The Sunnen CK-10 machines that located the block on the main saddles and finished the cylinders a true 90 degrees from them ushered in a new era of accuracy that we never previously knew. Once the main bearing saddles are perfectly straightened out and the cylinder bores are round, square, and properly located, and the deck is exactly parallel to the main bearing centerlines, then the engine block can be assumed to be accurate enough to proceed with. Ever notice when you get your block,crank, cam and pistons and rods back from a great machinist, how nicely they seem to go together and everything turns smoothly and they just feel like a good engine. If the block isn't right, nothing else around it will be,either.

[Larry Hill]

Mike a truing sleeve will help straighten the mandrel.

[MIKE JONES 302]

Originally Posted by Larry Hill

Mike a truing sleeve will help straighten the mandrel.

I turn the block 180 degrees to keep the mandrel tru. I adjust oil flow to slow down the honing rate. The 3 center mains can not be over stroked, they hone faster than 1 and 2 mains. I do use a truing sleeve on the rod hone mandrels, but I've never seen a truing sleeve for a line hone mandrel, but I just started machining. Could you post up an image of a "Line hone mandrel truing sleeve" Thanks

[Larry Hill]

It looks like a truing sleeve for the pin mandrel only bigger ID and longer made out of honed tubing. I like the oil holes 120* apart, drill the holes so they line up with oil feed holes on the machine. You will see the ware pattern on the shoes start to "come in"