M8 Tappet Retainers

[OLBLU]

Just wondering if anyone during "normal riding" ( 1500-4000 RPM ) has had any trouble with the M8 plastic tappet retainers self destructing?

I'm thinking of putting in a S and S 465G cam and was wondering if things like the aluminum tappet retainers and cam chest are worth the extra expense, if I'm not revving the hell out of it?

Thanks

 

[Jack Klarich]

Plastic tappet cuffs have been used in a lot of engine apps with very low failure rate

If you decide to change them during a cam install ( I would always change the lifters to wear in a new cam) you may want to change the cuffs, be forewarned there has been many reports of broken bolts during cuff removal

I believe the problem to be hydraulic locking of the bolts, bad JU JU

 

[OLBLU]

Thank you Jack. By broken bolts I assume you mean those tiny 12 pointers that hold the chrome tappet blocks? Apparently , if they are heated for 5 minutes with a heat gun this softens the factory loctite and they come right out.

If you meant something else , could please explain further?

 

[Jack Klarich]

Thank you Jack. By broken bolts I assume you mean those tiny 12 pointers that hold the chrome tappet blocks? Apparently , if they are heated for 5 minutes with a heat gun this softens the factory loctite and they come right out.

If you meant something else , could please explain further?

No, it is the bolt that holds the tappet cuff in place

If you drop the lifters out the bottom( into the cam chest there is NO need to mess with the cuffs, if you do want to change the cuffs have a look here

https://university.fuelmotousa.com/article/h-d-milwaukee-8-lifter-tappet-cuff-bolt-removal-tips/

 

[OLBLU]

Thanks again Jack. If it's that easy, I will put in the aluminum tappet cuffs. I had seen that page and don't know why I thought it meant the 12 point tappet block bolts.

Over 60 moment I guess. :blush:

 

[New Orleans Kevin]

S n S tapper cuffs

Just wondering if anyone during "normal riding" ( 1500-4000 RPM ) has had any trouble with the M8 plastic tappet retainers self destructing?

I'm thinking of putting in a S and S 465G cam and was wondering if things like the aluminum tappet retainers and cam chest are worth the extra expense, if I'm not revving the hell out of it?

Thanks

If you are already there For another $65 the plastic parts can go away. I used them when I had my camchest kit done on my street glide special. Well worth the money for the peace of mind. Also the new cam plate and high performance oil pump doubled the oil pressure. More oil pressure equal long-term engine life and cooler running.

This question reminds me of a Sir Mix-A-Lot song in which he said “silicone parts are made for toys”

 

[Mykneesbehurtin]

Thanks again Jack. If it's that easy, I will put in the aluminum tappet cuffs. I had seen that page and don't know why I thought it meant the 12 point tappet block bolts.

Over 60 moment I guess. :blush:

I have the S&S 465 cam and aluminum S&S tappet cuffs in my 17 M8 and although the cuffs do nothing for performance it is cheap piece of mind.