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Old 02-17-2010, 11:27 PM   #1
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Default DIY engine build:

Im getting ready to pull my engine to rebuild it and Im curious to know who all has built there own motors? Im doing this to save myself some money I dont have. Most of my parts will be sent to a machine-shop like the block and the head. ill be ordering some H beam rods and some forged pistons and I have heard things like the wrist-pins not fitting right so when I get those I will be sending them to a shop as well!

when you did assemble your motor:

what problems did you run into?
what parts did you use?
did you use oversize pistons?
ect ect.......

one other thing i am curious about is what exactly are the weak points withing the BP engine? im wanting to target all the weak points in the BP engines and improve them!

I will use this thread as guide/walkthough and update it as i go. This thread can also be used for others in the future that want to do a DIYengine build to save themselves some money!




my to buy list:

Rock Auto chrom-moly rings

Last edited by WonTon; 02-18-2010 at 12:40 AM.
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Old 02-17-2010, 11:30 PM   #2
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Did it all 100% myself including honing. I did use stock 9:1 pistons though. Weak point? Rods. Didn't really run into any problems. Used M-tuned rods.
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Old 02-17-2010, 11:33 PM   #3
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weak points:
factory rods
oil pump gears
solid lifter lash
sex with your busted boyfriend
improperly installed wrist pins
not going with a loose bore on the pistons
stfu, die of aids
this thread sucks
thanks for wasting the bandwidth
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Old 02-18-2010, 12:13 AM   #4
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im either going to be getting M-Tuned rods or 949 rods.....

did yall use OEM piston ring or is there a better option? i wish i had the tools and the ability to hone my own block and everything!
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Old 02-18-2010, 12:14 AM   #5
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Rock Auto chrom-moly rings just like Brainey is using. So far they're great
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Old 02-18-2010, 12:38 AM   #6
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sweet! back when i messed around with some SBC's i used chrome molly rings!

how much boost are you running 18psi? is it 18psi? im tossing the idea of using a slightly over-sized piston, but if i can get away with a good amount of boost on OEM pistons ill go that route!
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Old 02-18-2010, 08:51 AM   #7
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I'm in the middle of a build exactly like Vlad did...stock slugs with forged rods.

The advantage of using stock pistons is that as long as your cylinders are within tolerance, you can just re-hone it and assemble yourself. I'm not sending anything to a machine shop.

Disassemble head - hand tools
Port and Polish / gasket match somewhat, but not getting carried away - dremel
Clean valves - wire wheel
Lap valves - $4 lapper and some compound
New stem seals - Vitons from RockAuto
Clean hydraulic lifters and fill with synthetic
Reassemble head, with adjustable intake cam gear

Disassemble block
Measure cylinders - like hustler said, aim for loose, should be good with 100K mile OEM stuff
Hone Cylinders - $15 stone hone, or borrow a nice one that autosets the angle
Gap rings
Measure Mains and Rods, order bearings for proper clearance
Inspect crank, clean pistons
Check clearance with plastigauge when bearings arrive
Check again with proper torque, then watch online vid and check again assuming you did it wrong
Check pin fitment - leaving that one to NAPA...I can do .XXX work, but not that .XXXX ****
Assemble bottom end with Belfab rods, Sealed Power rings from RockAuto
New oil pump

Assemble


Most of the -good- rebuild kits come with cam seals, a CAS O-ring and all that. If you're in there...you might as well...


This kind of setup should be fine up to about 300whp as long as you don't get crazy with timing. Really all the components are good for the power, but ANY detonation at that power level will immediately kill your piston ringlands, whereas it would take 0.1s for the same to occur with forged parts.

I'll be tuning with Jeff's det cans without WI...then put the relay for the water back in as a security blanket.
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Old 02-18-2010, 01:01 PM   #8
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Quote:
Originally Posted by WonTon View Post
im either going to be getting M-Tuned rods or 949 rods.....

did yall use OEM piston ring or is there a better option? i wish i had the tools and the ability to hone my own block and everything!
If you don't need a bore, you can get a decent DIY hone with a "bottle brush" hone. You also need to match ring selection with cylinder finish. Cast iron, chrome moly and plasma rings can require a different cylinder wall finish. If you are going ultra low buck "ring & bearing job" (and your cylinder walls are still servicable), you can always try using a set of Deves cast steel (not iron) rings. Deves rings have a reputation for being able to seat in unfinished bores; lots of Volvophiles swear by them.
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Old 02-18-2010, 04:43 PM   #9
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Sean, I'll just give you my notebook full of notes, prices, and issues on my engine build, aside from you wanting to use forged pistons, you're copying it exactly.
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Old 02-18-2010, 05:39 PM   #10
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sweet! sounds good Rotornut!


thanks for all the feedback people! keep it coming!
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Old 02-18-2010, 07:35 PM   #11
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Brush Research Manufacturing: Industrial Brushes, Flexible Honing Tools, Wire Brushes make a DIY "dingleberry" hone. You will want the 280 grit.
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Old 02-19-2010, 07:50 PM   #12
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Glad I found this thread, will help when I get ready to build my engine..
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Old 02-19-2010, 08:48 PM   #13
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Quote:
Originally Posted by WonTon View Post
sweet! back when i messed around with some SBC's i used chrome molly rings!

how much boost are you running 18psi? is it 18psi? im tossing the idea of using a slightly over-sized piston, but if i can get away with a good amount of boost on OEM pistons ill go that route!
Nah, I wish. I ran 18+ on all my subaru's, so far the highest I've been on the miata is 14, but turned it down to 10 cause I'm a giant *****

To be honest, 10-12 on my turbo/engine is more than enough for me on the street for now
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Old 02-22-2010, 06:53 PM   #14
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What's the isue on the wristpin?
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Old 02-22-2010, 09:41 PM   #15
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Clearance needs to be checked on each pin in each rod small end.
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Old 02-22-2010, 10:04 PM   #16
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Quote:
Originally Posted by 18psi View Post
Nah, I wish. I ran 18+ on all my subaru's, so far the highest I've been on the miata is 14, but turned it down to 10 cause I'm a giant *****

To be honest, 10-12 on my turbo/engine is more than enough for me on the street for now
Come on....you only live once you know!
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Old 02-22-2010, 10:11 PM   #17
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We have many customers who have used OEM Pistons on the M-Tuned Rods and built their engines themselves.
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