Freshening up my 308

GrimGreaser

So I finally bit the bullet and pulled my head. No compression in one cylinder, 90 in one and 20-30 for the rest. Burned valves, one really toasted, and the ring pin came out of #4. The bores look and measure really good - can get by with a ring job, valves and valve seat work. My concern is with the piston missing the ring pin. Can I press a new pin in, or do I need a whole new piston? I don't really have the funds for much, I'm trying to get it up and running again till my situation improves. I'm having Hudson withdrawals...

rambos_ride

Seems like I have everything but engine parts..

Someone on here has to have a donor laying around for FREE (ok - cost of shipping?)

Anyone...?

"Buehler...Buehler...?"

Park_W

So, what's the bore size?

brumac

I have extras also.

GrimGreaser

Standard size 'B', 3.8125, with 0.001-0.002 wear, minimal taper (don't have my notes). I have some pistons from a free engine I was given, they had pin-less rings though (pin hole filled in) and not sure how they'll clean up.

brumac

My old block is marked "C" and "D" and the pistons were in there for 70,000 miles. I will be able to measure the pistons later today or tomorrow.
Bruce

brumac

Grim,
I have 3 pistons, one might be of use to you. They measure: 3.809; 3.8095; and 3.810. Measured as per fig. 23 on page 3-21 of the 48-52 manual. Let me know what you want to do. Bruce

GrimGreaser

Thanks Bruce, I'll let you know.

But I would still like to know if there is any issue with fitting a new pin into my piston?

Glowplug

No, if the ring lands and the piston top are not damaged. If you are planning to use non pinned rings you can cut a piece of pin and drive it into the top of the piston. Alternatively, the size of the hole is so small it will fill with carbon soon.
Great that you are doing a overhaul, this is how I kept my Hudsons running im the 60's -70's. Keep posting your progress.

brumac

Grim, the pistons are free, except for the cost of postage. Bruce

GrimGreaser

Bruce, those pistons marked the same as the block, or can you tell? 3.810 would be a 'B' piston, the smallest listed in the manual.

brumac

Grim, There are two "C's" and one "D". I measured them as per the manual however they show some normal wear on those surfaces.

GrimGreaser

Thanks Bruce, I'm going to try replacing my ring pin first. Appreciate, and the offer. I'll let you know if I need one of those pistons.

DavidC

Same here, 5 good free pstons available