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1275 Engine Returned from Machine Shop

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Bruce_B

Bruce_B

Jedi Warrior
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I picked up the 1275 engine from the machine shop. Here's a list of the work I had done. Might be informative to anyone looking to rebuild their engine. No work was done to the cylinder head because I have a Longeman head that I'll be using. Parens are my notes

DEGREASE & SHOT BLAST BLOCK
SONO BLOCK (Check for cracks)
MIC & CHECK SM. MAIN BEARING SADDLE
TAP OIL HOLES
DECK 4 CYL. BLOCK
REBORE 4 CYLINDER ENGINE +40
REMOVE CAM BEARINGS & INSTALL NEW
INSTALL FREEZE PLUGS
TAP ALL BOLT HOLES
DRILL & TAP 2 HEAD BOLT HOLES (from 9 to 11)
DRILL & TAP FUEL PUMP MOUNT WITH 3/8 NPT (For ventilation)
GRIND CAPS & RESIZE FOUR RODS
PRESS 4 PINS INTO PISTONS
BALANCE COMPLETE 4 CYLINDER
REMOVE BROKEN BOLT & HELICOIL
BALANCE FLYWHEEL ASSY
CLEAN CRANKSHAFT
SONO CRANKSHAFT
GRIND 7 JOURNAL SHAFT

Lots of work and it ain't cheap. I'll be checking their work to specs before I start putting the engine together.
Hopefully I thought of everything.
 
hehe, only thing not done was to balance the engine bits. Well could have lightened the flywheel as well.

All in all, great start for an engine.
 
It's going to sing again Pat.
 
Jack, - engine was balanced and I'm putting on an aluminum flywheel.

Pat - hopefully it will sing, but with a single SU - HIF44 (1.75")

I'll be asking plenty of questions along the way. I've got some household projects to finish before the engine assembly starts and also need warm weather. Can't wait!
 
Oh boy, you covered the last two items, it's all there, it.s going to sing for sure.
 
Bruce

You'll be singing alright.

One lil thing, if you have a reputable place do the hat on em, you be singing like a barber shop. /bcforum/images/%%GRAEMLIN_URL%%/wink.gif

Pat
 
GB1 said:
Bruce

You'll be singing alright.

One lil thing, if you have a reputable place do the hat on em, you be singing like a barber shop. /bcforum/images/%%GRAEMLIN_URL%%/wink.gif

Pat
Click to expand...

Pat,
Not sure I know what you mean by 'do the hat'. Are you talking about the clearance between the top of the carb and the bonnet?
 
Man, I bet that cost you a bundle. I hope the guy did you a real good job and you can have an engine that will last you a long time, buddy. How much extra power comes with boring it 40 over? How much wear was on the bores? I checked mine when I tore it apart and with 52,000 on it the wear was very minimal. I was glad of that so I could reuse the stock pistons. Are you going back with a stock cam? I would not go too hot on the cam or it won't idle good. At least that was my experience with the 1275 minis back in the 80s.
 
Kim, I hope he did a good job too. I don't know how many miles were one the engine, but there was a definite ridge on the bores.
Can't really say the horsepower gain by going to +40, overboring doesn't get you that much hp. If I had to guess I'd say maybe 2 - 3 hp. But it does increase the volume taken by the pistons so it affects Compression Ratio.

I'm going with the Swiftune cam. Power comes on around 1200 rpm up to about 6000. That's where I spend just about all of my time. I like torque - race to the next street light.
More to follow.....
 
Oh, yeah if you can feel a ridge then you have to do something. There was only one guy that I trusted to bore my engines and he has been dead some years now. I had a bad experience with a machine shop that did not do a good job on a motorcycle engine that I had bored out whe I was in my teens. I put in a set of brand new expensive weisco pistons and perfect circle rings (I think) and had it seize up on me after about 10 minutes of running easy. Was not bored quite big enough, pistona swelled as they do when heated. Got no justice from the machine shop. Thats when I learned to use mics and calipers and find out as much as I could. I still have a 2000cc pinto engine bored .060 over and put together and never started, sits in my dads basement. i wrecked the car before I could put the motor in. That was in 1984, I don't know what I will do with that engine. It can be turned but I don't know if the grease on the bearings is still good. I should tear it back apart before using it.
 
Tis my understanding that .60 is maybe 10 HP, would guess that .40 might be 6 Hp, that's all on a good day of course.
 
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