valve train pushrod geometry setting, weird question... maybe not |
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valve train pushrod geometry setting, weird question... maybe not |
orange914 |
Mar 18 2008, 05:23 PM
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#1
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http://5starmediaworks.com/index.html Group: Members Posts: 3,371 Joined: 26-March 05 From: Ceres, California Member No.: 3,818 Region Association: Northern California |
following the step by step valve geometry i've got a few possible issues? when no shims used and exhaust and intake geometry is set the swivel feet are almost bottomed out (almost no adjustment left). so next it was shimmed with .025, the geo/swivel tightness got better (not so close to bottoming against swivel) when shimmed with .040 shims i have more space to adjust up left before swivel contacts rocker (3/4 to 1 turn).
bottom line it seems to work out better with .040 shims. with no shims it has wider range of measurements between each valve -and- closer swivel foot to rocker arms. 1] is .040 shim o.k.? 2] if o.k. is 3/4 to 1 turn until swivel foot hits the bottom of the (modified) rocker acceptable? yes they are o.e.m. swivels from a 2.7 3] if not o.k. can i remove .030 or ? more from rocker arm 4] if none of the above is good what am i needing to do to correct this? mike |
Dominic |
Mar 18 2008, 06:14 PM
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#2
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Dominic Group: Members Posts: 992 Joined: 14-January 03 From: Vacaville, CA Member No.: 149 Region Association: Northern California |
"3] if not o.k. can i remove .030 or ? more from rocker arm"
Did you already grind off the required .060" off the rocker arm? If not, that may solve your problem. Do a search here for some rocker arm before and after pics. |
Borderline |
Mar 18 2008, 10:41 PM
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#3
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Senior Member Group: Members Posts: 720 Joined: 8-February 05 From: San Juan Bautista, CA Member No.: 3,577 Region Association: Northern California |
(IMG:style_emoticons/default/agree.gif) , yeah you gotta grind about .060 off the stock rocker arms. Were you using an adjustable pushrod? There are photos somewhere around here. I run more shims , but that's just me (IMG:style_emoticons/default/smile.gif)
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toon1 |
Mar 18 2008, 11:57 PM
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#4
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Senior Member Group: Members Posts: 1,849 Joined: 29-October 05 From: tracy,ca Member No.: 5,022 |
I helped Mike with the geo last sat.
The rockers where decked .060 We did have an adjustable p/r The p/r length numbers where very close accross the board, within 1.5 mm. I didn't feel comfy using more shims and thought he sould post here to get more input. BTW- Mike is using heads built by Len at LN eng. they are awsome! Keith |
DNHunt |
Mar 19 2008, 06:35 AM
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#5
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914 Wizard? No way. I got too much to learn. Group: Members Posts: 4,099 Joined: 21-April 03 From: Gig Harbor, WA Member No.: 598 |
I have .045 shims on my 2270 assembled at Jake's and beat on his dyno.
Dave |
toon1 |
Mar 19 2008, 11:18 AM
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#6
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Senior Member Group: Members Posts: 1,849 Joined: 29-October 05 From: tracy,ca Member No.: 5,022 |
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orange914 |
Mar 19 2008, 03:52 PM
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#7
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http://5starmediaworks.com/index.html Group: Members Posts: 3,371 Joined: 26-March 05 From: Ceres, California Member No.: 3,818 Region Association: Northern California |
I helped Mike with the geo last sat. The rockers where decked .060 We did have an adjustable p/r The p/r length numbers where very close accross the board, within 1.5 mm. I didn't feel comfy using more shims and thought he sould post here to get more input. BTW- Mike is using heads built by Len at LN eng. they are awsome! Keith keith spent alot of time was a big help getting these right on the money. (IMG:style_emoticons/default/thumb3d.gif) from hearing .040 is no big deal i think that the best route is the shims and an average cut on the exhaust pushrods (4) and an average cut on the intake pushrods (4)... MAYBE another .020 off the rockers. thats the most ify one, again) whats the census out there? mike |
G e o r g e |
Mar 19 2008, 04:01 PM
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#8
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Dr Group: Members Posts: 1,905 Joined: 20-September 05 From: Southern Cal Member No.: 4,832 Region Association: None |
QUOTE (the only engines that should need more than .030 correction shims are equipped with longer than stock valves, 99.5% of reader should NEVER need more than .030 pad shims). the quote is from jake were you able to get satisfactory settings before you added shims? if so why shim? just to allow more adjustability? are you setting these at zero lash? what push rods? |
toon1 |
Mar 19 2008, 04:48 PM
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#9
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Senior Member Group: Members Posts: 1,849 Joined: 29-October 05 From: tracy,ca Member No.: 5,022 |
QUOTE (the only engines that should need more than .030 correction shims are equipped with longer than stock valves, 99.5% of reader should NEVER need more than .030 pad shims). the quote is from jake were you able to get satisfactory settings before you added shims? if so why shim? just to allow more adjustability? are you setting these at zero lash? what push rods? I read that quote also. We where not able to get a satisfactory reading on the geo @ 1/2 lift without shims. The geo would be close but not perfect. Also the swivel foot was 1/2 turn away from the rocker. Even with the .040 shim there is only 3/4 of a turn from the rocker Yes, it was set at 0 lash They are the manton p/r's that Jake sells and uses and where provided by him wht the purchase of the valvetrain kit. The question is, WITH a .040 shim, the swivel foot is ONLY 3/4 of a turn from bottoming out aginst the rocker. I felt this is too close, Mike does too, BUT we are not sure. |
Jake Raby |
Mar 19 2008, 05:58 PM
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#10
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
QUOTE The question is, WITH a .040 shim, the swivel foot is ONLY 3/4 of a turn from bottoming out aginst the rocker. That means you have 3/4 of 1mm of valve adjustment allowable.. If your valves stretch that far they'll snapp off. |
toon1 |
Mar 19 2008, 09:12 PM
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#11
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Senior Member Group: Members Posts: 1,849 Joined: 29-October 05 From: tracy,ca Member No.: 5,022 |
QUOTE The question is, WITH a .040 shim, the swivel foot is ONLY 3/4 of a turn from bottoming out aginst the rocker. That means you have 3/4 of 1mm of valve adjustment allowable.. If your valves stretch that far they'll snapp off. Should we add more shim, take more off the rocker or both? |
orange914 |
Mar 19 2008, 11:30 PM
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#12
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http://5starmediaworks.com/index.html Group: Members Posts: 3,371 Joined: 26-March 05 From: Ceres, California Member No.: 3,818 Region Association: Northern California |
QUOTE The question is, WITH a .040 shim, the swivel foot is ONLY 3/4 of a turn from bottoming out aginst the rocker. That means you have 3/4 of 1mm of valve adjustment allowable.. If your valves stretch that far they'll snapp off. jake, with no shims we measered .440 INT. lift, and .419 EX. lift. Perfect valve train geometry at half lift had a bigger difference in lengths between intake and exhaust pushrods without a shim, but they were closer with .040 shims. (1)- i am not clear if .040 is advised or not needed? (2)-with no shims, having approx. half turn at most, will i have problems with swivil foot/rocker-arm interference? (3)-is it better to have a more equall exhaust and intake total lift that adding a .040 shim? |
G e o r g e |
Mar 19 2008, 11:49 PM
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#13
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Dr Group: Members Posts: 1,905 Joined: 20-September 05 From: Southern Cal Member No.: 4,832 Region Association: None |
mike what cam are you using?
in the valve train article jake says exhaust pushrods are generally 1 mm shorter on his cams what are you getting as your pushrod lengths? intake? exhaust? |
toon1 |
Mar 20 2008, 08:33 AM
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#14
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Senior Member Group: Members Posts: 1,849 Joined: 29-October 05 From: tracy,ca Member No.: 5,022 |
mike what cam are you using? in the valve train article jake says exhaust pushrods are generally 1 mm shorter on his cams what are you getting as your pushrod lengths? intake? exhaust? Mike is using Jakes 9550 cam. In the earlier postsI stated there is only about a 1.5mm delta between all 8 p/r's. The cam and p/r length is really not of concern. The concern is the swivel foot clearance in relation to the rocker and what to do about it, as posted ealier. I spent 11hrs with Mike making sure his geo was right. We where not able to get a satifactory geo ( at half lift ) w/o .040 shims. Keith |
cuca914 |
Mar 20 2008, 10:08 AM
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#15
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"Serenity now!!" Group: Members Posts: 301 Joined: 19-March 07 From: Rancho Cucamonga, CA Member No.: 7,609 Region Association: Southern California |
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orange914 |
Mar 20 2008, 01:17 PM
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#16
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http://5starmediaworks.com/index.html Group: Members Posts: 3,371 Joined: 26-March 05 From: Ceres, California Member No.: 3,818 Region Association: Northern California |
QUOTE The question is, WITH a .040 shim, the swivel foot is ONLY 3/4 of a turn from bottoming out aginst the rocker. That means you have 3/4 of 1mm of valve adjustment allowable.. If your valves stretch that far they'll snapp off. jake, with no shims we measered .440 INT. lift, and .419 EX. lift. Perfect valve train geometry at half lift had a bigger difference in lengths between intake and exhaust pushrods without a shim, but they were closer with .040 shims. (1)- i am not clear if .040 is advised or not needed? (2)-with no shims, having approx. half turn at most, will i have problems with swivil foot/rocker-arm interference? (3)-is it better to have a more equall exhaust and intake total lift that adding a .040 shim? so... the feedback i'm getting is: although the swivels are close to the rockers with no shims (3/8 to 1/2 turn from interferance), it isn't an issue. this is better than .040 shims no?? mike |
toon1 |
Mar 20 2008, 02:33 PM
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#17
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Senior Member Group: Members Posts: 1,849 Joined: 29-October 05 From: tracy,ca Member No.: 5,022 |
QUOTE The question is, WITH a .040 shim, the swivel foot is ONLY 3/4 of a turn from bottoming out aginst the rocker. That means you have 3/4 of 1mm of valve adjustment allowable.. If your valves stretch that far they'll snapp off. jake, with no shims we measered .440 INT. lift, and .419 EX. lift. Perfect valve train geometry at half lift had a bigger difference in lengths between intake and exhaust pushrods without a shim, but they were closer with .040 shims. (1)- i am not clear if .040 is advised or not needed? (2)-with no shims, having approx. half turn at most, will i have problems with swivil foot/rocker-arm interference? (3)-is it better to have a more equall exhaust and intake total lift that adding a .040 shim? so... the feedback i'm getting is: although the swivels are close to the rockers with no shims (3/8 to 1/2 turn from interferance), it isn't an issue. this is better than .040 shims no?? mike I think it's the other way around. With the swivel feet being so close to the rocker, if the valve stretches, you will run out of adjustment, not good. If I understand it right, what Jake is saying, 3/4 of a mm is NOT good We definitly need the shim. shims are not a bad thing (escpecially if they are nesacarry), we just need to know weather or not to add more. |
SirAndy |
Mar 20 2008, 02:42 PM
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#18
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Resident German Group: Admin Posts: 41,651 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
If I understand it right, what Jake is saying, 3/4 of a mm is NOT good if i understand jake correctly, he was saying 3/4 of 1 mm is PLENTY because if the valve ever stretches that much, it'll snapp off long before you bottom out your adjustment ... (IMG:style_emoticons/default/idea.gif) Andy |
VaccaRabite |
Mar 20 2008, 02:44 PM
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#19
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En Garde! Group: Admin Posts: 13,446 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region |
Why would it be bad to deck the arm a little more instead of adding more shim? Is shimming just easier then decking? I can't see how a .070 deck would provide less structure then a .060 deck.
But I am a noob, and am watching this thread like a hawk (cause I am going to need to do it soon). Zach |
toon1 |
Mar 20 2008, 02:54 PM
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#20
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Senior Member Group: Members Posts: 1,849 Joined: 29-October 05 From: tracy,ca Member No.: 5,022 |
If I understand it right, what Jake is saying, 3/4 of a mm is NOT good if i understand jake correctly, he was saying 3/4 of 1 mm is PLENTY because if the valve ever stretches that much, it'll snapp off long before you bottom out your adjustment ... (IMG:style_emoticons/default/idea.gif) Andy Thank's Andy, you're right! (IMG:style_emoticons/default/WTF.gif) was I thinking! sorry Mike, my bad!. |
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