401 turbo motor build

Tony's post inspired me to post the details of my turbo motor as it goes together.  No real progress at this point but I spent most of the day cleaning stuff and going through parts.

Crank is back from being welded.  I went through the local parts store as my normal crank guy is backed up pretty bad.  They were only supposed to weld and grind the thrust and leave everything standard, it came back .010/.010, ugh.  They're getting me bearings for the mix-up so I guess I can live with it.  We'll see how the clearances look, they were dead-on at standard.


Rods and pistons assembled.  They're the old K1 rods with 3/8 bolts.  I'd prefer 7/16 but that's what I've got so I'll run it.  Pistons are the Wiseco Pro Tru dished pistons, 4.195 bore.


Timing cover ready to go.  It's just an old stocker and it's got it's battle scars in the pump housing but it works just fine.  Casting flash knocked out of the passages but that's it for mods.  I just did a quick tear down and inspection and buttoned it right back up.  Water pump is an old Flowkooler aluminum unit.


Block in the hone.  Probably hone it on Tuesday.  It's got aluminum spray welded to #8 cylinder wall but aside from that it's fine.  Should clean up well enough to use.

I'll probably gap them pretty conservatively loose.  I'd rather go too much than butt the rings.  Mid .030s I'd guess.  Haven't even thought about it yet to be honest.

What were yours gapped at and how much power/boost were you making?

Mine were gapped around 22 or 4 thou per inch bore plus 2 or 3 extra. Boost was a conservative 9 lbs with same bottom end as you talk. New K1 rods new Wiseco pistons. took both pistons top groove out with no signs of detonation anywhere. Pistons were #4 and#3.

goops wrote: Mine were gapped around 22 or 4 thou per inch bore plus 2 or 3 extra. Boost was a conservative 9 lbs with same bottom end as you talk. New K1 rods new Wiseco pistons. took both pistons top groove out with no signs of detonation anywhere. Pistons were #4 and#3.

Yeah, that's pretty tight, make sure you change that next time and it'll be fine.  I ran the Pro Tru flat tops before this, didn't get a chance to lean on them too hard (only 12 psi) but I didn't have a boost related failure.  Unfortunately I had hurt one with nitrous before it was turbocharged and did not realize it.  That's why I went with the dished ones this time.  They should be able to put up with a bunch of boost I would think.

dbomb wrote: put some acidic toilet bowl cleaner on that number 8 cylinder swarf and watch it sizzle while ya eat a sandwich .Might help save your hone stones

It's not too bad, honed right out.

Very Nice. Port work looks great too. I wish I was courageous enough to even just gasket match.....