Can I use a roll pin/spring pin for pinning my crank with a Magnacharger pin kit?
#1
Can I use a roll pin/spring pin for pinning my crank with a Magnacharger pin kit?
I am trying to get my crank pulley pinned while everything is apart. I have the Magnacharger crank pinning kit but no dowel pins. I called the machinist that is doing my heads and he suggested using a roll pin instead. A roll pin is a hollow pin with a slit going the length of the pin.
I know that waiting for solid a dowel pin is the "safe" thing to do, but I want to get this done now. Besides, a solid dowel might be overkill. Any suggestions? Would a roll pin work good enough?
I know that waiting for solid a dowel pin is the "safe" thing to do, but I want to get this done now. Besides, a solid dowel might be overkill. Any suggestions? Would a roll pin work good enough?
The following users liked this post:
Dazedcowboy (03-01-2023)
The following users liked this post:
Dazedcowboy (03-01-2023)
#4
Yea, I was thinking about both of those things. The bolt is way undersized, and the drill bit is a little closer... though the drill bit is pretty brittle.
I might try the bolts after I drill, but before I use the reamer.
I really wanted the roll pins to work, but I'm not willing to be the first person to try it. I don't think roll pins were made to be loaded up parallel with the slit in the pin.
I might try the bolts after I drill, but before I use the reamer.
I really wanted the roll pins to work, but I'm not willing to be the first person to try it. I don't think roll pins were made to be loaded up parallel with the slit in the pin.
The following users liked this post:
Dazedcowboy (03-01-2023)
Trending Topics
#8
TECH Apprentice
iTrader: (30)
NO! don't it! The strength and hardness of a dowel pin is much stronger than a drill bit piece or a roll pin. I tried using the drill bit method in desperation once (carbide bit) Sheared the bit in half in no time and marred my crank snout. Get some dowels from ATI to save yourself from a headache.
it was double pinned btw..
it was double pinned btw..
#11
Gotcha, yea if you look at McMasterCarr's website, the shear strength of their alloy dowel pin is 10,000 lbs and the shear strength of the roll pin is about 7,000 lbs. The issue is how the roll pin is going to be loaded - that 7,000 lb number is probably the shear strength perpendicular to the slit, rather than parallel with the slit, which is how I would be using it.
The machinist I talked to said not to use a drill bit for that reason.
I am hoping I will be able to use the bolt - it'll be pretty strong. I mean really... a grade 5 or grade 8 bolt is going to be pretty darn tough!! If the bolt shaft has too much play, I'll just wait and order some dowel pins.
Alloy steel dowel pins are REALLY hard to find locally. None at Home Depot, Ace Hardware, Sears Hardware, True Value, etc. I checked them all... even those 50+ year old mom and pop places that stock everything. If you want them you need to order from McMaster, Fastenal, eBay, internet vendors, etc.
The machinist I talked to said not to use a drill bit for that reason.
I am hoping I will be able to use the bolt - it'll be pretty strong. I mean really... a grade 5 or grade 8 bolt is going to be pretty darn tough!! If the bolt shaft has too much play, I'll just wait and order some dowel pins.
Alloy steel dowel pins are REALLY hard to find locally. None at Home Depot, Ace Hardware, Sears Hardware, True Value, etc. I checked them all... even those 50+ year old mom and pop places that stock everything. If you want them you need to order from McMaster, Fastenal, eBay, internet vendors, etc.
#12
TECH Addict
iTrader: (22)
NO! don't it! The strength and hardness of a dowel pin is much stronger than a drill bit piece or a roll pin. I tried using the drill bit method in desperation once (carbide bit) Sheared the bit in half in no time and marred my crank snout. Get some dowels from ATI to save yourself from a headache.
it was double pinned btw..
it was double pinned btw..
What special type of steel do you think dowel pins are made of?
Do not use a dowel pin, they have empty space in the center which allows them to crush. A solid pin must be completely fractured horizontally to spin the balancer. Pins in general are rated for shear strength. You wont find info on fracturing along the axis, that number will be ridiculously high and impossible to calculate from your balancer. Also, do not use a butter bolt grade 5, that stuff is softer than common mild steel. Grade 8 is plenty strong, but keep in mind bolts are not machined to the same tolerance as drill bits/dowels so you will likely have some play in the hole which can lead to the balancer moving ever so slightly. If you want to get REALLY technical, get a taper dowel pin with an interference fit on the big end
Last edited by Pocket; 02-11-2012 at 02:38 PM.
The following users liked this post:
Dazedcowboy (03-01-2023)
#13
TECH Apprentice
iTrader: (30)
An ATI dowel pin is much stronger than a drill bit or a roll pin. Yes it happened to me. Sorry no pics. This happened about 7 years ago.
I was surprised myself. I would never thought you would be able to shear a carbide drill bit in half this way but it did it. This was with a stock crank and a D1SC maxed out.
I was surprised myself. I would never thought you would be able to shear a carbide drill bit in half this way but it did it. This was with a stock crank and a D1SC maxed out.
The following users liked this post:
Dazedcowboy (03-01-2023)
#14
A dowel pin is solid and a roll pin is hollow.
I actually had a shot at a tapered dowel pin but I passed on it. I wanted something that would fill the whole hole at the point where the crank pulley meets the crank snout. I tapered dowel pin would fill the whole hole on only one side of the pin. I don't know if I saw the same pins you are thinking of, but the ones I saw had quite a noticeable taper to them.
I think I am going to play it safe and just wait for a dowel pin. I am using a borrowed Magnacharger pinning kit, and one of the holes is egg-shaped a little from the previous install. Therefore, I am just going to use a single dowel pin and do it right.
BTW, my crank pulley is from a supercharged Cadillac CTS-V, and it looks like GM used a 3/16" key. If they're only using a 3/16" key, I am pretty sure my 1/4" dowel will be fine!
I actually had a shot at a tapered dowel pin but I passed on it. I wanted something that would fill the whole hole at the point where the crank pulley meets the crank snout. I tapered dowel pin would fill the whole hole on only one side of the pin. I don't know if I saw the same pins you are thinking of, but the ones I saw had quite a noticeable taper to them.
I think I am going to play it safe and just wait for a dowel pin. I am using a borrowed Magnacharger pinning kit, and one of the holes is egg-shaped a little from the previous install. Therefore, I am just going to use a single dowel pin and do it right.
BTW, my crank pulley is from a supercharged Cadillac CTS-V, and it looks like GM used a 3/16" key. If they're only using a 3/16" key, I am pretty sure my 1/4" dowel will be fine!
#15
TECH Addict
iTrader: (22)
Tapered pins arent cones, they're a set diameter on one end and the small end is a few thousandths smaller, you have to put a set of calipers on it to see which end is which. Do a search on Mcmaster, you want .25" x .75" long
Dont try to reuse an old pin or keyway, eyeball the balancer on the snout as best you can and drill a new hole. You do NOT want to egg out or try to cram a round pin into a square hole when it comes to the balancer. Slop encourages pin failure because of the extra play
Dont try to reuse an old pin or keyway, eyeball the balancer on the snout as best you can and drill a new hole. You do NOT want to egg out or try to cram a round pin into a square hole when it comes to the balancer. Slop encourages pin failure because of the extra play
#16
I think I am going to pass on the tapered pins. I want a uniform fit through the entire hole. The bolt shafts I measured are between .242" and .248", varying from bolt to bolt. The small end of that 3/4" taper pin at McMaster Carr is .243.
The ream is marked as .2495, but when I measure the cutting edges with my caliper, it comes out to more like .2515... not sure why.
I thought about it, but the edges of the keyway would be wider than the new hole. Reusing that spot would be a bad idea.
The ream is marked as .2495, but when I measure the cutting edges with my caliper, it comes out to more like .2515... not sure why.
I thought about it, but the edges of the keyway would be wider than the new hole. Reusing that spot would be a bad idea.