924Board.org

[RC]

Anyone have a dimension for the length of stock guides?
Cant find a reference in FSM or PETs.

Measure mine at 59.5mm for intake and exhaust. Know the NA ones are different length and since these look like they may have been replaced am not sure if what was fitted is correct. Appreciate a number if you have a stripped head or new guides lying around.

[ideola]

Now I'm looking for this information too. Anybody have it?
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erstwhile owner of just about every 924 variant ever made

[ideola]

This thread indicates that the 931 intake guides are 60mm long and the exhaust guides are 55mm long. Can anyone confirm? TIA.
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erstwhile owner of just about every 924 variant ever made

[RC]

Which thread Dan?
Not like you to forget the link.

Close enough, 59.5 - 60mm.

The 55mm ex & 60mm in sound like the NA guides to me, although I haven`t the figures available ATM.

Sure that I measured both in & ex the same on a 931 head, and most likely checked all 8 of them. The NA guides are about 5 -6mm (IIRC) difference. This is because the inlet valve springs sit on a stepped spring seat while the exhaust are on a rotator, sitting 5-6mm higher. As the 931 head comes, ALL valve springs sit on a rotator.

[ideola]

Whoops.
http://www.924board.org/viewtopic.php?t=9770

It's an oldie, but Smoothie indicates the 931 has the different size intake and exhaust guides...
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erstwhile owner of just about every 924 variant ever made

[Cedric]

This confuses me, I have these valve guides. They seemed to be longer than the stock ones but accordning to you they should be 55 and 60 (mines are 56.5 and 60) I rememberd that the one with the grove on was the exhaust one. But that also seems to be wrong.

Acoording to my mail correspondance with peter utzon in 2006 he told me his exhaust guides were 56.5mm.

I need to take good look at my old guides, which seemed to be much shorter, hmm..


Does your guides look like this?

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1980 924 Turbo
www.instagram.com/garagecedric/

[gegge]

Do you have the diameter of the guides? I am considering fitting valves with a thinner stem and have to order blanks.
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Carl Fredrik Torkildsen

924 turbo -81 Carrera GT RESTOMOD
924 turbo -80 Dolomite De Luxe
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924s -86 Black on black turbo with Fuchs

[RC]

Sorry gegge. Must have overlooked the notification as just came across this via search. Was actually looking for what I vaguely recall you may have posted, some info on smaller stem and/or OE valves.

Stock guides are nominal 9mm ID and 14mm OD. By whatever length.

Came across this fairly comprehensive listing recently, at least for US imports, from VTM, which appears to be an evolution of SI.

http://www.vtmvalvetrain.com/pdfs/valve-guides.pdf

Same part #s as SI, but easier to access data, except for all imperial measurements. Here`s a progressive size listing, again American with inches.

http://ebookbrowse.com/gdoc.php?id=109101137&url=a23f2b0bc165d11ada29c75a6e720300

There`s quite a few suitable candidates for 8mm stems with the same 14mm OD. The only guide I can see worth considering for 7mm stems however is one from the GM 2.2L. Nominal 7mm ID with a 0.5830" O.D. WTF that = 14.8mm OD. Looks like IN and EX are only different by length. This is SI`s listing:

http://www.sivalves.com/ocforeign_vguides_chevy_import.html

Shouldn`t be a major drama making these fit if you have a good lathe in your garage.

Recall that you have spent some time researching various OE components, particularly from Euro engines. Hopefully you`ve progressed much faster and further than me. Did you find any useful interchange data on the valve train? What have you done or are doing with your top end?
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World`s quickest 924 2L slushbox

[emoore924]

IIRC, when my machinist built one of my big valve heads, the stock 9mm valves were NLA (or at least not worth looking for) and we used 8mm. So the guides were for an 8mm valve. And the guides were further modified to allow better flow through the head (shortened?). Anyhoo, if you're interested, PM me and I can dig the builder's build notes out, or put you in touch with him. He's probably willing to discuss details of what he remembers... All that being said, I think I have some new 9mm stock valves lying around. Could make a deal on those if you need 'em but I think the valves *and* the guides were getting hard to find in 9mm sizes....

[ideola]

For what it's worth, I can get SI stainless valves and guides all day long in 9mm...
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erstwhile owner of just about every 924 variant ever made

[morghen]

thats weird...mine dont look like that...i dont know about the length..but mine look rounded...something like a bullet shape
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Supercharger and EFI kits
https://www.the924.com

[emoore924]

[RC]

Anyone who really wants 9mm valves, as an easy OE stock replacement, for a 931 or NA, can get them from SI, ebay, wherever.
http://www.rpmmachine.com/si-valves-porsche.shtml

Going to 8mm stem valves is fairly easy using off the shelf parts. Heaps of guides to chose from with nominal 8mm ID and 14mm OD. 7mm is more difficult as I cant find any OE guides with sufficient OD, except for the ones above. Still, merely reducing the OD is a cheap & basic job at most shops anyway. Not even worth me pricing a batch of custom ones, but if Ideola wants to ...

Blank 7mm valves are available anywhere good valves are sold. Again, if one has access to a lathe or machine shop its a basic job to cut a groove, anywhere you like, not necessarily stock position, considering compression height, clearances, lift.

http://www.revvalves.com/home.php?cat=222