Author Topic: Proper taper pin peening procedure (Read 11047 times)

bob b · « **on:** October 18, 2014, 03:38:08 AM »

Hello any and all,

67 degrees at 10 pm, Oct 17, in northern vermont. Perfect time to try a different cam in my twin.

I have been using a blunt air chisel and a heavy buck. Is there a less brutal way?

Thanks!

38ac · « **Reply #1 on:** October 18, 2014, 03:46:26 AM »

They are not supposed to be peened.

bob b · « **Reply #2 on:** October 18, 2014, 03:57:08 AM »

How do you prevent it from falling out? Is peen the wrong word?

dieselgman · « **Reply #3 on:** October 18, 2014, 04:20:31 AM »

It is supposed to be a precision taper with slight interference fit... they do not fall out if everything fits exactly. Are you working with original Lister parts? and are they in perfect condition?

dieselgman

bob b · « **Reply #4 on:** October 18, 2014, 04:45:34 AM »

Uh, no.

The offside injector lobe would wiggle unless I REALLY whacked it.

I just thought of leaving the pin full length. Heating it cherry where the little end would protrude the lobe collar. Install, buck, and smack the long little end.

Then cut off the excess.

Too many beers?

Cam going back in. Not even drunk yet.

fabricator · « **Reply #5 on:** October 18, 2014, 12:49:34 PM »

If you think it might fall out that wont hurt anything, my only other question is what the hell were you other two malcontents doing up at that hour to respond?

dieselgman · « **Reply #6 on:** October 18, 2014, 01:53:34 PM »

I would never leave one of those taper pins loose, and never allow one of the lobes to wobble! If the fit is poor, then that needs to be fixed first.

I am in Alaska, so that accounts for some of the crazy hours... responding to East Coast clients at 4:00 am has become a way of life! I usually refrain from growling, but it does still happen once in awhile. Reading this forum and responding to questions once in awhile is my recreation when I can't go back to sleep!

dieselgman

bob b · « **Reply #7 on:** October 18, 2014, 04:00:04 PM »

Good morning and thanks for the replies.

I'm pretty sure the Indian parts are just jig drilled with two different size bits. Definitely not machined as one.

I guess my question is:

Hit the big end and buck the little end OR hit the little end and buck the big end.

Would hot riveting change that?

fabricator · « **Reply #8 on:** October 18, 2014, 05:29:00 PM »

Myself I would probably do this http://www.mscdirect.com/browse/tn/Holemaking/Reamers/Taper-Reamers/Taper-Pin-Reamers-Sets/Taper-Pin-Reamers?navid=12106200
But if you don't want to or don't have time to get a reamer, I would heat it up and knock it in so there is no wobble at all and just mushroom the small end a little it wont take much, after it cools down make sure there is still no wobble, if there is knock the big end until it goes away.
Yeah I forgot about the Alaska thing, still curious what 38 was doing up at O dark thirty surfin the web.

bob b · « **Reply #9 on:** October 18, 2014, 06:05:51 PM »

Well duh by me.

I guess this is what happens when projects are initiated by beer.

I have the reamer. I bought it after struggling with this a couple of years ago. I kept knocking the pin back out.

I just can't bring myself to not lock it somehow. My technique was the problem, not the theory.

I'll try the hot rivet method, hitting the big and bucking the little, and report back. (After reaming of course)

Thanks fab!

I

dieselgman · « **Reply #10 on:** October 18, 2014, 07:03:27 PM »

Are those pins #6, or #5? Does anyone recall?

And has anyone tried the taper flute vs the spiral flute reamer for clean results?

I concur that some of the Indian stuff needs to be cleaned up quite a bit, although a couple 8/1 cams I have dismantled did have the proper taper in the bore. I found that the Indian pins themselves were pretty coarse.

dieselgman

bob b · « **Reply #11 on:** October 18, 2014, 07:39:14 PM »

I just used the spiral #7 I bought and FWIW I'll be getting the straight. The spiral I have has a round shank. I'm using vice grips on it but

dieselgman · « **Reply #12 on:** October 18, 2014, 07:54:15 PM »

I noted #6 pins mentioned in prior posts about this topic.
Making a very clean fit will keep things tight and together. I have seen some original Dursley pins that had to be drilled out because they had been seated so tightly, but they were not peened in place.

dieselgman

bob b · « **Reply #13 on:** October 18, 2014, 08:15:55 PM »

Hmmm. I've been using #7 pins and I bought a #7 reamer.

FWIW, the hot rivet method didn't work. Grows the pin to much.

bob b · « **Reply #14 on:** October 18, 2014, 09:05:47 PM »

Well now I am confused. I just tried my #7 reamer on another cam and it won't go all the way through. However, the #7 pins do.

I guess I don't understand the system.

After reaming the cam in my engine, it was much better. No wiggle after a couple taps. I ended up doing the peening as usual. One side then the other.

Rat a tat tat. Oh well.

Thanks!

News: