Straight 6 rebuild Advice

As far as the block goes as a minimum, I would plan on a hot tanking or the newer style of baking with bead blasting (depends on the shop), then an overbore to clean up the cylinders and new cam bearings. Then you will need to have the crank cleaned, checked for straightness, and the journals polished or ground. You will also need your rods reconditioned and if you can afford it, have everything balanced. At this point your mechanic can assemble the shortblock.

verify the compression ratio by cc head chamber. make sure machinist decks block for .000 deck height. this alone will make the difference.

Mystang66 said:

I am preparing to pull the 3.3l 200 straight six out of my 66 Mustang. I have a mechanic acquantance that is going to rebuild the engine for me once it is machined. I'm calling around to machine shops trying to get an idea of the cost for machining and they want me to specify what I want done. What should tell the I want done as far as machining of this engine block/head?

Also, any idea what I should be willing to pay for the machining? I have had shops quote me a few hundred and others quote $1500 to $2000.

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the first thing you want the machinist to do is check the block for twisting.

next have them check the block deck for square.

then the cylinder bores need to be checked for taper and out of round.

after that check the main bearing saddles to make sure they are level and round.

if any of these surfaces is out of spec, then they need machining to bring them back where they should be.

for the head the deck surface needs to be checked for square as well as the exhaust mounting flange.

a valve job should be done regardless to make sure they are sealing properly.

as to specific mods, before you have the machine shop zero deck the block, make sure of the pistons and the cylinder heads you are going to use are not going to run your compression ratio too high for pump gas. older heads have smaller chambers and with a zero deck block you can run into problems with too high of a compression ratio. check out Classic Inlines Performance Parts - Home for a good compression ratio calculator. also understand that the head gasket you choose will have an effect on compression ratio. for instance the stock six cylinder head gasket was a steel shim variety that had a compressed thickness of .025", and the usual replacement gasket is a fiber one that has a compressed thickness of double that. so take that into consideration before having the block deck and head surface milled.

also take into account that most years the stock rocker arms are non adjustable, and all are shaft mounted, so if you do mill the block and or the head, remember to properly shim the rocker arm shaft pedestals so that you get the proper geometry back.