Need good advice on rebuilding my motor

[BuickMike]

I finally pulled the motor from my GN at 135K miles due to a blown headgasket. It pretty much went over time due to erosion of the graphite. As far as the heads go, I decided to get some Champion Irons. After pricing out getting my heads rebuilt / ported they seem like the smart choice to me. Where I need help is with the bottom end. My GN needs ALOT of work and I don't want to go overboard on a motor that will be intended for more street than strip use. Things still look in good shape. The bearings are scored, but not worn down to the copper anywhere. The pic below is a good representation of what all my bearings look like. I used plastigauge to check the clearances. The rods looked like around .0015ish and the mains looked like about .0018ish. I know it's not accurate, but it still looks like clearances were tight. Oil pressure was never a problem with this motor. I used my dial caliper to check the journals. The mains were all between 2.496" and 2.497". The rod journals were between 2.245" and 2.246". The bores look clean. There are no real scratches and I can't even hook my fingernail on a ridge at the top. Check out the pics below.

What I want to know is if I can get away with honing the cylinders, polishing the crank, putting in some new standard bearings, TRW Forged Pistons, rings, new cam, and call it done?

 

[BuickMike]

More pics

 

[turbo6mike]

I would forsure put some billet center mains and put a good forged pistons.I just had mine rebuilt because this summer I had cracked a block and broke a tranny case because I had a stock cap break and everything fell out the bottom of the motor.The new motor I had done was by weber racing wiseco pistons,center caps with studs.Good luck just make sure the bottom end is strong.

 

[Whut]

I would also suggest a strong bottom end. If you want a number to a shop that will treat you fair and knows how to build these 109's just PM me. I blew a head in mine as well and decided to build a 109 rather than build a stage due to the limited funds I had. My motor is solid, needed very little (most due to shipping) work before being dropped into the car. I run FAST so with a little tuning the car is running mid 11's with less than 20 PSI and a nice fat tune to keep it safe.

 

[Just a Six??]

Main caps & studs are a good start.

 

[steve hughes]

If you plan to keep it conservative with the combo you have like maybe high or even mid elevens if your pistons look good and aren't too loose in the bores hone it and put new rings and bearings in it. If it ain't broke don't fool with it and you'll save a lot of headaches. Come up wit a game plan how fast you really want to go and be honest with yourself.

 

[BuickMike]

I'm looking to have a mid 11 second motor on race gas. I'll be going a little bigger on the turbo / injectors eventually. Believe it or not I know when to say stop. I'm never going to want to get a transbrake and do 1.5 and faster 60ft times. i get to the dragstrip maybe 4 times a year at most.

I will definately be going with all ARP fastners, but do you guys really think Billet mains are a must?

 

[BuickMike]

Ok, I guess the billet center main caps are not that much. ($149 at Cotton's) My question is, do I need to have additional machining done to fit them?

 

[boostingbuick]

Yes, you will need to have the block line bored.

 

[steve hughes]

I would Not do billet caps on an 11.50 motor. If the caps are not fit properly you you will have major problems. I'm running 9.40's with stock caps and an aluminum girdle. If it were me i would hone it , resize the rods with ARP bolt, check the mains for size and put new rings and bearings in it.

 

[WHITE T]

I agree with Steve.

If all you are looking for is 11's, don't even mess with it. Arp main studs, billet caps are not needed.

Save the money for other areas of the build, it will add up very very quickly

 

[BuickMike]

Thanks guys. Sounds like I should just leave the stock pistons? Now for the dumb question. What exactly is resizing the rods?

 

[BadAssGN]

I'm with the others, Don't get carried away with an 11 sec engine

Your stuff looks great.

I would find a reputable machine shop to measure the bores and piston clearance.

if its good, leave it. Forged Pistons are not needed for your goals.


ARP rod bolts are stronger than stock, using them requires the Rod cap be milled down a bit and then the big end of the Rod is Machined back to the stock size.

HTH