Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

DLC coating

Thread Tools
 
Search this Thread
 
Old May 23, 2007 | 04:09 PM
  #1  
BC's Avatar
BC
Thread Starter
Rennlist Member
20 Year Member
 
Joined: Dec 2001
Posts: 25,186
Likes: 105
Default DLC coating

I wanted to do this but have run into 2 issues.

1) They only do NEW parts, not used ones.
2) They cost 32 dollars a lifter. 32x32 is a 1024 price tag. Ouch.

The reason was I am using stronger springs and a slightly bigger cam, and will go to 7,000rpm for various reasons on occasion.

I guess I could just do swain coatings, but they are more sacrificial.
Reply
Old May 23, 2007 | 04:18 PM
  #2  
BC's Avatar
BC
Thread Starter
Rennlist Member
20 Year Member
 
Joined: Dec 2001
Posts: 25,186
Likes: 105
Default

I talked to swain and they said they don't like doing hyrolic lifters, as contaminants could get into them.

I guess I will just polish them to a very high shine and slather on the assembly lube good and thick.
Reply
Old May 23, 2007 | 05:25 PM
  #3  
6.0-928S's Avatar
6.0-928S
Rennlist Member
20 Year Member
 
Joined: Nov 2004
Posts: 951
Likes: 1
From: Conshohocken,Pa.
Default

Hi Brendan,
Are the cam & the lifters both used?
Hammer
Reply
Old May 23, 2007 | 06:13 PM
  #4  
hans14914's Avatar
hans14914
Rennlist Member
20 Year Member
 
Joined: Aug 2003
Posts: 2,679
Likes: 356
From: Indianapolis
Default

Why not get some nice light-weight solid lifters fabbed up? With all the work that has gone into your project, it may be cheap insurance. Sure you have to shim them, but they will accept the coating, and never bleed down high in the rev range. Just an idea. I had Kent and Arrow both quote a set for my audi stroker a couple years ago, and dont remember it being that bad. Albeit the exchange rate has gone to pot. I dont know of any good american lifer shops though.
Hans
Reply
Old May 23, 2007 | 06:27 PM
  #5  
BC's Avatar
BC
Thread Starter
Rennlist Member
20 Year Member
 
Joined: Dec 2001
Posts: 25,186
Likes: 105
Default

Originally Posted by hans14914
Why not get some nice light-weight solid lifters fabbed up? With all the work that has gone into your project, it may be cheap insurance. Sure you have to shim them, but they will accept the coating, and never bleed down high in the rev range. Just an idea. I had Kent and Arrow both quote a set for my audi stroker a couple years ago, and dont remember it being that bad. Albeit the exchange rate has gone to pot. I dont know of any good american lifer shops though.
Hans
I may do that for the stroker. I will want to spin that thing high. This engine is just a warmed over 5.0L with arp bolts and studs on everything, drilled crank, and will get some boost.
Reply
Old May 23, 2007 | 06:27 PM
  #6  
BC's Avatar
BC
Thread Starter
Rennlist Member
20 Year Member
 
Joined: Dec 2001
Posts: 25,186
Likes: 105
Default

Originally Posted by 6.0-928S
Hi Brendan,
Are the cam & the lifters both used?
Hammer

Correct. 86 cams, cut for the S4 heads, and the lifters are original.
Reply
Old May 23, 2007 | 06:41 PM
  #7  
hans14914's Avatar
hans14914
Rennlist Member
20 Year Member
 
Joined: Aug 2003
Posts: 2,679
Likes: 356
From: Indianapolis
Default

Since hammer had success on the ati damper group buy, you may have luck with the same guys for solid lifters. If i had a choice, i would go with Arrow. No doubt they make the best in the business. Plus, they offer a DLC coating option, also micropolishing... etc. I am sure you already know, but here is the website if you are feeling lazy,

http://www.arrowprecision.co.uk/

Fantastic rods, lifters, and lash-caps. If I could afford to use them on every project, I would.
Hans
Reply
Old May 23, 2007 | 06:56 PM
  #8  
RyanPerrella's Avatar
RyanPerrella
Nordschleife Master
15 Year Member
 
Joined: Apr 2006
Posts: 8,934
Likes: 3
From: theporscheconnection.com
Default

Ive had DLC (Diamond Like Carbon) priced out by a firm in China or Japan before and found it allot more reasonable then it was here in the states. That was 3-4 years ago mind you. But I would try another supplier.

I would agree though that your better off with a lighter lifter then with a lower friction surface on the ones you have. The Porsche lifters are pretty big and very heavy.
Reply
Old May 23, 2007 | 07:10 PM
  #9  
BC's Avatar
BC
Thread Starter
Rennlist Member
20 Year Member
 
Joined: Dec 2001
Posts: 25,186
Likes: 105
Default

Originally Posted by RyanPerrella
Ive had DLC (Diamond Like Carbon) priced out by a firm in China or Japan before and found it allot more reasonable then it was here in the states. That was 3-4 years ago mind you. But I would try another supplier.

I would agree though that your better off with a lighter lifter then with a lower friction surface on the ones you have. The Porsche lifters are pretty big and very heavy.
Then I will go in that direction probably - for the big engine. I wonder how the shimming would work.
Reply
Old May 23, 2007 | 07:33 PM
  #10  
Mike Simard's Avatar
Mike Simard
Three Wheelin'
 
Joined: Aug 2006
Posts: 1,765
Likes: 3
From: Atlanta
Default

Originally Posted by hans14914
Since hammer had success on the ati damper group buy, you may have luck with the same guys for solid lifters.
http://www.arrowprecision.co.uk/
Hans
I would be interested in some lash cap adjustable tappets if someone wants to initiate it, we would also need a bunch of 7mm stem lash caps. The body size is 35mm and that's used in other applications like VW and Alfa.
Reply
Old May 23, 2007 | 07:51 PM
  #11  
BC's Avatar
BC
Thread Starter
Rennlist Member
20 Year Member
 
Joined: Dec 2001
Posts: 25,186
Likes: 105
Default

SO the check would be with the cam covers off, but to actually change the lash it would be with the cams off?
Reply
Old May 23, 2007 | 07:58 PM
  #12  
V2Rocket's Avatar
V2Rocket
Rainman
Rennlist Member
15 Year Member
 
Joined: Jan 2007
Posts: 45,844
Likes: 783
From: Nashville, TN
Default

According to Performance Products, entirely new valves would be $40 apiece.
Reply
Old May 23, 2007 | 08:02 PM
  #13  
BC's Avatar
BC
Thread Starter
Rennlist Member
20 Year Member
 
Joined: Dec 2001
Posts: 25,186
Likes: 105
Default

Originally Posted by V2Rocket_aka944
According to Performance Products, entirely new valves would be $40 apiece.
New Lifters is what we are talking about, but for valves, I think some of our sponsors have them for in the low 30s.
Reply
Old May 23, 2007 | 08:08 PM
  #14  
Mike Simard's Avatar
Mike Simard
Three Wheelin'
 
Joined: Aug 2006
Posts: 1,765
Likes: 3
From: Atlanta
Default

Originally Posted by BrendanC
but to actually change the lash it would be with the cams off?
yeah, it takes adjusting the valves to a new level, you have to really be into it
The other way, like a VW, is to compress the lifter at the edges and slip a big ole shim into place. That style is easy to adjust but heavy, like having a manhole cover sitting on top of the lifter ready to flop around as soon as valves start floating. The shim under the bucket (lash cap) style does require removing the cam to adjust but is the lightest possible lifter. As long as the valve seats and valves have good mating surfaces, valves shouldn't need frequent adjustment. One advantage of lightweight valve train components is that you can use lighter spring pressures which benefits the whole valvetrain from the timing belt to the valve seats.
Reply
Old May 23, 2007 | 08:21 PM
  #15  
BC's Avatar
BC
Thread Starter
Rennlist Member
20 Year Member
 
Joined: Dec 2001
Posts: 25,186
Likes: 105
Default

Originally Posted by Mike Simard
yeah, it takes adjusting the valves to a new level, you have to really be into it
The other way, like a VW, is to compress the lifter at the edges and slip a big ole shim into place. That style is easy to adjust but heavy, like having a manhole cover sitting on top of the lifter ready to flop around as soon as valves start floating. The shim under the bucket (lash cap) style does require removing the cam to adjust but is the lightest possible lifter. As long as the valve seats and valves have good mating surfaces, valves shouldn't need frequent adjustment. One advantage of lightweight valve train components is that you can use lighter spring pressures which benefits the whole valvetrain from the timing belt to the valve seats.
Cool. I'm thinking cut down base circles from S3 cams anyway, so I will have custom stem lengths. May as well go all out on the solids. 7L, Solids, Big valves. Cool.
Reply



All times are GMT -3. The time now is 06:31 PM.