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Group Buy: Solid Lifter Upgrade
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endwrench  



Joined: 07 Dec 2002
Posts: 1629
Location: Victor, Montana

PostPosted: Wed Feb 20, 2008 12:50 pm    Post subject: Reply with quote

Martijnus, I was under the same illusion as you as to how the shims worked until I talked to Min about his setup. The shims actually go on top of the valve rather than the top of the lifter like most stock setups I have seen. I'd like to see a picture of both the shim and the underneath of the lifter.

Todd
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'79 924NA. Rebuilt 9.5:1, MSDS header, Mega Squirt Injection, MJLJ-EDIS Ignition, 1.6L Whipple Charger and Intercooler, 10lbs Boost, 944 Trans, Custom HD Clutch.
"simsport" said....superchargers are better than turbos its official!....
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dpw928  



Joined: 02 Nov 2002
Posts: 1860
Location: owasso, ok 74055

PostPosted: Thu Feb 21, 2008 12:37 am    Post subject: Reply with quote

The 924 head isn't like the VW and Audi versions in that there is no retaining wall for a shim on top of the lifter. That's why the shim/adjustment point must be between the valve stem and bottom of the lifter.

If someone is going to produce an aftermarket lifter, why not go hydraulic like on the 928?

Dennis
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78 928 5 sp Silver
78 928 AT Euro Black
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bass gt  



Joined: 02 Dec 2004
Posts: 971
Location: Johannesburg for now!!

PostPosted: Thu Feb 21, 2008 1:06 am    Post subject: Reply with quote

Dan,

This may come as no suprise to you, but i have these piper followers in my engines. Regarding the Q as to the worth of fitting them, i believe they are worth it for several reasons.
1) Much lighter than the stock item.
2) Much lighter than the stock item. When i say lighter, i really mean lighter. From memoery, the weight of 2 stock followers is equivalent to all 8 piper followers. There really is a noticable difference in the engine with these fitted.
3) Better performing, due to the weight issue.
If you are fitting a new cam, i think these are essential. Why wreck a good cam with suspect followers?
Now, i have had a couple of sets from Piper, and both came with the shims. 6mm is ideal, and a good engine shop will have plenty of scope to machine these down.
Now, i have had no problem with Piper, but one batch did take in excess of 3 months to arrive!! So perhaps Arrow are the better bet. Arrow are a superb company, they supplied my steel rods. The items would be faultless from them, and well worth the extra couple of $ in my opinion.
Now, if your next question is about dry sump pumps, i know all about those too

Steve
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bass gt  



Joined: 02 Dec 2004
Posts: 971
Location: Johannesburg for now!!

PostPosted: Thu Feb 21, 2008 1:06 am    Post subject: Reply with quote

Dan,

This may come as no suprise to you, but i have these piper followers in my engines. Regarding the Q as to the worth of fitting them, i believe they are worth it for several reasons.
1) Much lighter than the stock item.
2) Much lighter than the stock item. When i say lighter, i really mean lighter. From memoery, the weight of 2 stock followers is equivalent to all 8 piper followers. There really is a noticable difference in the engine with these fitted.
3) Better performing, due to the weight issue.
If you are fitting a new cam, i think these are essential. Why wreck a good cam with suspect followers?
Now, i have had a couple of sets from Piper, and both came with the shims. 6mm is ideal, and a good engine shop will have plenty of scope to machine these down.
Now, i have had no problem with Piper, but one batch did take in excess of 3 months to arrive!! So perhaps Arrow are the better bet. Arrow are a superb company, they supplied my steel rods. The items would be faultless from them, and well worth the extra couple of $ in my opinion.
Now, if your next question is about dry sump pumps, i know all about those too
Remember. Build it once. Build it right

Steve
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Min  



Joined: 04 Nov 2002
Posts: 2368
Location: Vernon, British Columbia, Canada

PostPosted: Thu Feb 21, 2008 1:50 am    Post subject: Reply with quote

endwrench wrote:
Martijnus, I was under the same illusion as you as to how the shims worked until I talked to Min about his setup. The shims actually go on top of the valve rather than the top of the lifter like most stock setups I have seen. I'd like to see a picture of both the shim and the underneath of the lifter.

Todd


After some looking and talking with piper, their shims actually go on the bottom of the lifter, rather than the top of the valve like I figured. Same deal really though.

Min
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bass gt  



Joined: 02 Dec 2004
Posts: 971
Location: Johannesburg for now!!

PostPosted: Thu Feb 21, 2008 1:57 am    Post subject: Reply with quote

Min,

The shim sits in a tube in the underside of the follower. The tube then slides onto the valve stem, hence setting he clearance. Simple really.

Steve
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dpw928  



Joined: 02 Nov 2002
Posts: 1860
Location: owasso, ok 74055

PostPosted: Thu Feb 21, 2008 2:02 am    Post subject: Reply with quote

bass gt wrote:
Min,

The shim sits in a tube in the underside of the follower. The tube then slides onto the valve stem, hence setting he clearance. Simple really.

Steve


Except that the cam has to be removed for each valve adjustment.

Dennis
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78 928 5 sp Silver
78 928 AT Euro Black
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ideola  



Joined: 01 Oct 2004
Posts: 15506
Location: Woodstock IL

PostPosted: Thu Feb 21, 2008 2:06 am    Post subject: Reply with quote

Regarding ARP, I have no doubt about the excellence of their product. However, I am concerned about lead time. They haven't made these before, so it would be a completely new R&D effort for them, and guess who gets to pay for that Also, it only adds to the lead time...by the time we ship them a sample, give them the 4 week lead time they need, and wait for them to be shipped back, we're talking a minimum of 6 weeks. That puts me into June before I can get send the head to Eurorace. I don't want to wait that long if I can avoid it.

For point of comparison, here is the response I got from Nick Frazer at ARP:
Nick @ ARP wrote:
Hello Daniel,
Thank you for your enquiry.
We do not have a stock cam follower available off the shelf to suit the Porsche 924 so we would have to custom make them for you.
Using the dimensions supplied by you or a sample follower, we would produce a design drawing of the cam followers for your approval prior to manufacture.
I estimate the cost to be approximately:
3 sets (24)..........28.00 GBP per follower
4 sets (32)..........22.00 GBP per follower
5 sets (40)..........19.00 GBP per follower
Lead time for production would be 4 weeks from design approval with a deposit of 25% required to secure the order.

More expensive, less experience (with our specific lifters), and a very long wait = less desirable
I'd really like to find a source here in the US, and I'm still working that angle, but so far no luck.

dpw928 wrote:
If someone is going to produce an aftermarket lifter, why not go hydraulic like on the 928?

Because my R&D budget isn't big enough.
[EDIT]
It might also be interesting to read this article about solid vs. hydraulic lifters in the 944.
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Rasta Monsta  



Joined: 12 Jul 2006
Posts: 11380
Location: PacNW

PostPosted: Thu Feb 21, 2008 2:49 am    Post subject: Reply with quote

Plus, hydraulic lifters need an oil galley in the head to pressurize them.
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Martijnus  



Joined: 29 Dec 2006
Posts: 2019
Location: Netherlands

PostPosted: Thu Feb 21, 2008 3:01 am    Post subject: Reply with quote

dpw928 wrote:
bass gt wrote:
Min,

The shim sits in a tube in the underside of the follower. The tube then slides onto the valve stem, hence setting he clearance. Simple really.

Steve


Except that the cam has to be removed for each valve adjustment.

Dennis


That has to be done anyway...whether the shims are on top or beneath the lifter.

Quote:
The 924 head isn't like the VW and Audi versions in that there is no retaining wall for a shim on top of the lifter. That's why the shim/adjustment point must be between the valve stem and bottom of the lifter.

If someone is going to produce an aftermarket lifter, why not go hydraulic like on the 928?

Dennis


The retaining wall can be machined...right? That's the whole point, you don't use the stock lifters, so any lifter can be made, with or without retaining wall.

I first thought they'd go on top, never seen shims beneath the lifter... always on top or the lifter itself (opel).

The weight loss is a serious advantage imho!

If it is possible to go hydraulic, that would be awesome... could there be a way to split the oil tube above the cam? if so, you have oil pressure from there and in theory no oil loss because the lifters don't use oil themselves...which doesn't affect the oiling of the cam...

but there have to be channels in the head to feed the lifters and I guess that isn't easy to build in the head.... can't bolt on something which feeds the lifters..

I'll think about this... with some creativity it could be done
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924 "50-jahre", 1981.
MSII/extra, LPG, ITB's, 5lug.
To be turbo'ed in a while.
Killed her at the Nurburgring, Porscheless at the moment
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bass gt  



Joined: 02 Dec 2004
Posts: 971
Location: Johannesburg for now!!

PostPosted: Thu Feb 21, 2008 3:38 am    Post subject: Reply with quote

hydraulic?? why??for what advantage?? hydraulic lifters are for ease of maintenance, not performance. the weight addition is horrific
really, once you take the time to measure up the cam to follower clearences, machine the shims, fit them, you are set. Period.
Anyway, if you have your smarts about you, you get the shop doing the head work to do this as part of the job. because, it goes without question you are having the ports matched, the valves upsized, a 3 angle valve job, new guides blended into the throat wall ect....
Re the followers, Piper are the naturalchoice, as they are an item they make, but the lead time can be very long. They told me 2 weeks, then another, and another. Turned into 3 months. i guess it depends where in the production cycle you land. But with a group buy, perhaps they will push them through asap. however, the Arrow price is better than the piper i think.
Also, when upgrading these followers, don't skimp and fit the stock springs. a) these will be 30 years old and prety tired b) once you up the boost and rpm, they just are not man enough. Put one on a spring gauge, and then do the maths re boost ect. Go for double springs, no doubt.
really, the efect on the engine is quite remarkable. it seems much more responsive with just the valve train upgraded.
So Dan, welcome to the thin end of the wedge. I remember being there once. Worse than a crack habit i think!!
Oh, BTW, i had my car runing N/A the other week. All this lightening work seems to have a result. The car wont idle below 1400 rpm, and it's a pig to move at slow speed. Revs flare and die, clutch(AP 6 Paddle) is a pig, but give it a sqirt, and Really picks up, and revs Soooo cleanly. Sounds the nuts, if i say so myself!!

Steve
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ideola  



Joined: 01 Oct 2004
Posts: 15506
Location: Woodstock IL

PostPosted: Thu Feb 21, 2008 3:47 am    Post subject: Reply with quote

bass gt wrote:
you get the shop doing the head work to do this as part of the job

Bingo!!! Exactly my plan...already reached out to Eurorace. I discussed my build with Jorge, and he recommended the uprated springs, titanium clips and guides, and possibly even turning down the valve stems.

bass gt wrote:
So Dan, welcome to the thin end of the wedge. I remember being there once. Worse than a crack habit i think!!

Haha, it's an addiction alright!
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Min  



Joined: 04 Nov 2002
Posts: 2368
Location: Vernon, British Columbia, Canada

PostPosted: Thu Feb 21, 2008 5:10 am    Post subject: Reply with quote

the real problem for me is when we run in our brand new integral cam, we have to run different valve lash than when the thing is finishing being run in. So we'll have to set the valve lash ourselves.

Min
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Rasta Monsta  



Joined: 12 Jul 2006
Posts: 11380
Location: PacNW

PostPosted: Thu Feb 21, 2008 5:17 am    Post subject: Reply with quote

So, about the valve replacement. . .I thought 931 valves were special material and/or fill. Will the Eurorace "big valves" be similarly made? I have a spare head I am interested in sending off.
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bass gt  



Joined: 02 Dec 2004
Posts: 971
Location: Johannesburg for now!!

PostPosted: Thu Feb 21, 2008 5:23 am    Post subject: Reply with quote

Min wrote:
the real problem for me is when we run in our brand new integral cam, we have to run different valve lash than when the thing is finishing being run in. So we'll have to set the valve lash ourselves.

Min


Min,

Fit the cam into the head, and use the stock adjusters to get you close enough. Start the engine and run at 2000-3000 rpm for a while. Bingo, cam is bedded in. The remove cam, fit solid followers, measure all clearences and machine shims. Fit, measure, and enjoy.


Steve
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