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daniel
Joined: 18 Jun 2009 Posts: 670 Location: Sydney, Australia
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Posted: Wed Dec 21, 2022 4:38 pm Post subject: Daniel's light weight valve's |
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Hi All
I know a few have gone down this route with custom made valves, so heres my take on it:
Rebuilding the engine in my race car (924 2.0) which currently uses a standard turbo head in a NA application. I decided to get something a bit better. Reading various posts/info and considering I am only allowed a bore at 87.75mm (class rules) I settled early on using the standard valve head diameters of 40mm & 37mm however I wanted a thinner stem to improve flow and reduce weight.
The advice I got was that 6mm may be OK but 7mm will be safe with the cam I am using (peak power 7500-8000rpm). So 7mm it is.
Off I went to a racing head shop that promised me the world and delivered squat. 6 months later I demanded the head back and decided to see what I could achieve on my own. I now have all parts to assemble the head. Cam is a custom grind on a blank & valves & guides are custom made. All other parts are off the shelf from various different motors (some unique to Australia).
The retainers are from a AU Falcon 6 cyl 4.0L.
The springs are a performance version from a Holden Gemini (double spring)
Collets (or valve locks) are from a 1FZ Toyota.
I am going to machine some custom spacers to give the desired spring pressure.
So now I am waiting until next year to have the seats cut, valves finished off and guides pushed in and reamed. I have been told Feb-March so will go back to working on my slide on camper project so I've got somewhere to stay at the track...
Here are the pics:
New intake valve, retainer, collets and solid lifter:
Original intake valve, collets, retainer and Porsche lifter (with adjustment screw).
New valves and old valves:
New guides, old guides
_________________ Over the top of skyline, total brake failure.... hit the wall at over 200 kp/h at the dipper, so anyone who has to brake for the esses is a pussy.
1977.5 Race Car, CAMS Group S Spec
1989 944 Cabriolet |
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924RACR
Joined: 29 Jul 2001 Posts: 8815 Location: Royal Oak, MI, USA
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Posted: Wed Dec 21, 2022 9:55 pm Post subject: |
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Very interesting stuff.
What are you doing for valve adjustment, with this different solid lifter? That's a topic I have to address with the Elgin cam still, due to the different base circle... too busy chasing other things at the moment... _________________ Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype |
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MikeJinCO
Joined: 08 Jun 2010 Posts: 1228 Location: Maysville, Colorado
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Posted: Thu Dec 22, 2022 12:45 am Post subject: |
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Two options. If using the stock lifters, I think some motorcycle shims might fit in the 9mm bore of the lifter. I think Ideola figured that out. Independent bike shops probably have boxes of shims around. If using the ACM solid lifters, when I had a reground Elgin cam, I put a Manley 8mm .080 shim upside down on the ACM stem and that put me about mid range for using Alfa 1300(105 engine) 9mm lifter shims. I told Hayes, and Chuck followed him. I believe 50plus has a lot of them or available from Centerline Alfa individually. When we set the head up we assembled it and used something like some .125 stock as a spacer, measured the clearance just purchased what we needed. More accurate than I expected, 7 out of 8 ok first round. Just ground .002 off the end of the valve for the eighth. Commonly done in shops these days to to the vast variety of shims.
Pleasure to meet you in Phoenix, I have a full page of notes. _________________ Mike
'67 MG Midget Dp
'71 Ocelot Dsr Kawasaki 1000(under rebuild) |
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daniel
Joined: 18 Jun 2009 Posts: 670 Location: Sydney, Australia
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Posted: Thu Dec 22, 2022 7:33 am Post subject: |
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Using 7mm ID lash caps. Available in thickness up to 6.5mm. _________________ Over the top of skyline, total brake failure.... hit the wall at over 200 kp/h at the dipper, so anyone who has to brake for the esses is a pussy.
1977.5 Race Car, CAMS Group S Spec
1989 944 Cabriolet |
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Mike9311
Joined: 14 Dec 2004 Posts: 1678 Location: Chicago-ish
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Posted: Fri Dec 23, 2022 7:03 am Post subject: |
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This is really awesome. You are putting a lot of thought and time into this! Oh the endless searching to find something that works. Good stuff! _________________ 1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car |
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Fifty50Plus
Joined: 28 Feb 2008 Posts: 1361 Location: Washington DC area
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Posted: Sat Dec 24, 2022 4:56 am Post subject: |
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I just ran the entire season with the Swedish lifters (8 mm Manley lash cap upside down in the cap) and the Alfa 9 mm lash caps on the valve stems. No problems whatsoever. Building two more H Prod engines over the winter with the same configuration. _________________ 1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car |
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924RACR
Joined: 29 Jul 2001 Posts: 8815 Location: Royal Oak, MI, USA
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Posted: Tue Jan 03, 2023 1:38 am Post subject: |
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Fifty50Plus wrote: | I just ran the entire season with the Swedish lifters (8 mm Manley lash cap upside down in the cap) and the Alfa 9 mm lash caps on the valve stems... |
Care to share some links to part numbers, sources etc? I need to get this sorted out still for our HP motor, get it ready for the Mid-O HP race! _________________ Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype |
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Fifty50Plus
Joined: 28 Feb 2008 Posts: 1361 Location: Washington DC area
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Posted: Tue Jan 03, 2023 4:21 am Post subject: |
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Vaughan, I was looking on the internet for more of the ACM lifters last night and couldn't find their site. I called Mike since he had sent me a set last month when he sold off his 924 stuff. He's looking for his old source and will get back to me. The Manley 8mm lash caps are readily available. As for the 9mm Alfa lash caps, I had to order both a small sizes set a larger range set to get the range that I thought I needed. As I recall, each set was several hundred pieces in incremental sizing. I can't recall which sized set was the proper range but each set was about $500.
I'm at the beach right now but will check when I get home and let you know which set was the right range and where I purchased it.
Setting the proper lash was easier than i orignally thought. I had pulled my IT-B cam out of the head while still in the car. I pulled all the Porsche lifters and one at a time, put in the Manley equipped ACM lifter and an initial Alfa 9mm lash cap. I positioned the Elgin cam over the lifter (just held it in by hand) and measured the lash. I did a little math and by the second or third Alfa lash cap I had the correct lash for that lobe of the cam. I repeated the process seven more times, put in all the lifters, lined up the Elgin cam and bolted it down, installed the timing belt, remeasured (plus or minus a thou) and fired it up. _________________ 1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car |
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Fifty50Plus
Joined: 28 Feb 2008 Posts: 1361 Location: Washington DC area
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Posted: Tue Jan 03, 2023 4:32 am Post subject: |
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I'm in the process of building two or three more H-Prod engines this winter for Hayes, myself and Matti Vilkkila (local IT-B racer convert) with all new parts, lighter rods, higher compression pistons, etc. I have heads at the machine shop now and figure that my initial set up as described above will work even before bolting the heads to the blocks. But when I did it to my well used IT-B engine, the valves were fully seated from running. On initial startup of these new engines, I expect the clearances to change as the valves and seats wear in and a complete re-measurement will be necessary before race ready. _________________ 1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car |
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924RACR
Joined: 29 Jul 2001 Posts: 8815 Location: Royal Oak, MI, USA
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Posted: Tue Jan 03, 2023 10:42 pm Post subject: |
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Cool... if you have that many builds upcoming, maybe some group buys on some of the components for the top end setup?
Definitely no rush, we can catch up when you get back. _________________ Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype |
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Mike9311
Joined: 14 Dec 2004 Posts: 1678 Location: Chicago-ish
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Posted: Wed Jan 04, 2023 12:21 am Post subject: |
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https://acm.se/category/760
They must have redid the site. My old link didn't work but their site is still there. I can't read Swedish but my German and some guessing helps
In theory I could make these but gladly they are still there so I don't have to _________________ 1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car |
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924RACR
Joined: 29 Jul 2001 Posts: 8815 Location: Royal Oak, MI, USA
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Posted: Wed Jan 04, 2023 12:39 am Post subject: |
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Mike9311 wrote: | https://acm.se/category/760
They must have redid the site. My old link didn't work but their site is still there. I can't read Swedish but my German and some guessing helps
In theory I could make these but gladly they are still there so I don't have to |
Awesome! Actually they have a button top right corner to translate to UK.
These look like the exact right part, 1200Kr for a set of 8, not bad!
https://acm.se/category/760/product/VT-385-8
Yeah, conversion rate is still close on 1Kr = $0.10, so about $120 for a set plus shipping etc... nice.
Will wait for an update from Chuck, but happy to fire off an order for a set or two any time... _________________ Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype |
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Mike9311
Joined: 14 Dec 2004 Posts: 1678 Location: Chicago-ish
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Posted: Wed Jan 04, 2023 4:33 am Post subject: |
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Quote "Awesome! Actually they have a button top right corner to translate to UK. "
Hilarious I had a script blocker on that blocked the UK button _________________ 1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car |
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Cedric
Joined: 27 Aug 2004 Posts: 2614 Location: Sweden
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Posted: Wed Jan 04, 2023 4:55 am Post subject: |
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Some of us can read Swedish if you need any help:). ACM bought all the stuff that the ol guy Sten parner SPM did, and took up the parts in their store. Hence a name change over the years.
Our Swedish Currency has completely tanked against the gbp,euro and dollar. Enjoy that, while everything i want to buy abroad gets even more expensive:) _________________ 1980 924 Turbo
www.instagram.com/garagecedric/ |
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Fifty50Plus
Joined: 28 Feb 2008 Posts: 1361 Location: Washington DC area
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Posted: Thu Jan 05, 2023 1:02 am Post subject: |
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Okay, I'm back home and found my info on the lifters and shims.
You all are correct, ACM is the outfit that makes the 924 sized lifter without the Porsche adjuster but the 8mm step inside. Hayes and I put a Manley 8mm lash cap (wear cap part No. 42125 - 8 ) inside the lifter.
We then used Alfa 9mm lash caps placed on top of the stock 924 NA valve stems to get the proper valve adjustment.
I bought two Alfa 9mm lash cap kits (small and large) from Centerline International, 1450 Overlook Drive, Lafayette, CO 80026, phone 888-750 ALFA. Their website is www.centerlinealfa.com. The kit that I needed was the smaller sizes 1500 - 2500 and there are 41 incremental sizes (going up by .0025 per step) in that range. Each size came with 5 lash caps in the kit and looking in my kit, I see that I used caps in the range 1625 - 1975 when I set my Elgin cam in my used IT-B head. Even with a fresh head (minimally cut seats and new valves) I don't think I will ever need to use the larger shims (2525 - 3500).
Centerline told me that they sell replacement shims based on size to keep the kit fully stocked but I haven't contacted them to reorder shims that I used. _________________ 1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car |
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