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machine shop questions

Guest Anonymous

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Guest Anonymous


hey everyone, i got my "new" 121ti motor torn apart

(thanks for the vid kris!) and am getting ready to

send it off to the shop for work. am i forgetting

anything major? this is my first rebuild so let me

know if i'm a dumbass.

-hot tank block/head and all accessories(timing

covers, oil pan, valve cover, etc.)

-enlarge exhaust to 46mm (it's got 44's)

-measure everything to see if it's in spec (main

bore, cylinders, pistons, crank, head height,

rockers/shaft) and replace what is worn

-install new valve guides and seals

-balance bottom end

anything you folks can add? all input is


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Guest Anonymous

Unless you have reasons to believe otherwise, you should count on new pistons (and having the block punched).

My list. . .


Hot Tank

New Freeze plugs

Bore for oversize pistons


New valve guides

New valves (you're buying new intake valves anyway)

Magniflux to check for cracks

Have the head surfaced (just to be safe)

Check rocker shafts and rockers carefully for wear

Machine work:

Dynamically balance the crank

Recondition rods

New Parts:

New pistons

new rings (I like Deves)

new rod and main bearings

I wouldn't bother having the block decked or having the bearings line bored or checked.


John N

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Guest Anonymous

Also some places like Metric Mechanic sells a top end rebuild kit that

includes all the stuff in the top of the motor. Things like rocker arms,

valve guides, valve seals and a bunch of other stuff. Have the rods shot

peaned and then resized and use new rod bolts. Don't forget to spend

money on ballancing. Some people don't think it's worth it for power

but I can tell you that it's worth it for a street engine.


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Guest Anonymous

Take your freeze plugs out before you take the block in as they will charge you to remove them. The blocks hot bath and the solution for the head are different and the heads cost will be more expensive to clean. In Denver cost of head rebuild varies greatly. I have used a shop that does a complete rebuild including disassembly (you furnish parts) for $300. As far as I know you cannot magnaflux an aluminum head. It requires a pressure check which I highly reccomend. Have the crank checked and dont go borderline. Have it ground if your even close to oversize. When you get the block back wash out all the water and oil passageways as the machine shop will do 75% percent of required. Youll need a cylinder hone before reinstalling pistons and if your close to overbore bite the bullit with new or used oversize....Good luck

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