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| Lash Caps on Stainless Valves https://ausmini.com/forums/viewtopic.php?f=5&t=88180 |
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| Author: | MiniBob [ Thu Jan 01, 2015 5:54 pm ] |
| Post subject: | Lash Caps on Stainless Valves |
I see a lot of ads for their use but has anybody used them on A Series? Are they necessary to prevent roller rockers from wearing the top of a stainless valve stem (wear would be U shaped from the roller??). Opinions and suggestions from my peers please 
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| Author: | drmini in aust [ Thu Jan 01, 2015 6:04 pm ] |
| Post subject: | Re: Lash Caps on Stainless Valves |
I had a set of S/S inlet valves that got severely radiused by roller rockers in a very short time, so I would say, YES! Good idea. |
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| Author: | MiniBob [ Thu Jan 01, 2015 6:17 pm ] |
| Post subject: | Re: Lash Caps on Stainless Valves |
drmini in aust wrote: I had a set of S/S inlet valves that got severely radiused by roller rockers in a very short time, so I would say, YES! Good idea. Thanks again Doc. I'll measure the stems and have a look-see on the interweb. Do you know of any stockists? One small worry; is there the possibility they can come off? |
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| Author: | Scoop [ Thu Jan 01, 2015 6:29 pm ] |
| Post subject: | Re: Lash Caps on Stainless Valves |
Maybe a dab of locktite could help the worry? |
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| Author: | drmini in aust [ Thu Jan 01, 2015 9:53 pm ] |
| Post subject: | Re: Lash Caps on Stainless Valves |
They won't come off, think about it... the bits are all travelling in each direction, together. They are common on many more modern engines. |
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| Author: | MiniBob [ Thu Jan 01, 2015 10:18 pm ] |
| Post subject: | Re: Lash Caps on Stainless Valves |
Thanks for putting that straight |
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| Author: | boomini [ Thu Jan 01, 2015 10:52 pm ] |
| Post subject: | Re: Lash Caps on Stainless Valves |
Lash caps are designed to rotate on the valve stem too so I wouldnt be using lock tight. They sre very unlikely to come off. |
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| Author: | carbon [ Fri Jan 02, 2015 6:24 am ] |
| Post subject: | Re: Lash Caps on Stainless Valves |
Minibob - there are quite a lot of the 6mm valve set-ups for A-series which use lash caps. These are normally used along with valve retainer cap which is machines to allow snug fit for the lash cap. The standard A-series valve stem is 9/32 inch, close to 7mm. |
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| Author: | MiniBob [ Sat Jan 03, 2015 11:10 am ] |
| Post subject: | Re: Lash Caps on Stainless Valves |
Thanks Carbon. My understanding is that they go on the stem above the collett and are a push fit. I can't go by standard measurements because the s/s valves are part of the alloy head I'm fitting. Will need to measure them. |
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| Author: | Hobson [ Thu Jan 08, 2015 2:03 pm ] |
| Post subject: | Re: Lash Caps on Stainless Valves |
I did't know what lash caps were, found this after a google search, yeah they are probably a good idea. http://ls1tech.com/forums/generation-iv-internal-engine/1509661-public-service-announcement-w-pics-lash-caps-important.html |
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| Author: | MiniBob [ Fri Jan 09, 2015 1:57 pm ] |
| Post subject: | Re: Lash Caps on Stainless Valves |
Thanks for posting the pics, very interesting to see the damage caused. |
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| Author: | drmini in aust [ Fri Jan 09, 2015 2:57 pm ] |
| Post subject: | Re: Lash Caps on Stainless Valves |
Regardless what was said in that LS1 forum, stock S/S valve stems are pretty soft. Good valves have hardened or stellited stem ends. |
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| Author: | Hobson [ Fri Jan 09, 2015 3:37 pm ] |
| Post subject: | Re: Lash Caps on Stainless Valves |
It was more of a what could happen, and more the photos showing, ignoring most of what they said. I assume that those pics are a good representation of what could happen? |
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| Author: | drmini in aust [ Fri Jan 09, 2015 6:02 pm ] |
| Post subject: | Re: Lash Caps on Stainless Valves |
Yank pushrod motors run a heap of valve spring pressure, they have to. Never seen that sort of valve or cap damage on an A series though, worst case the end of the valve stem gets burred out a bit or gets a radius in it. Unlike most V8 motors, A series valves don't spin, they are gripped tight by the collets. A+ triple groove collet ones can though. |
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| Author: | Besser [ Wed Feb 11, 2015 10:17 am ] |
| Post subject: | Re: Lash Caps on Stainless Valves |
Spent lots of time fettling the nissan/datsun L20B and they use lash pads. When the pad thickness starts to get over 5.5mm they can jump out in operation. The aftermarket alloy valve caps use a very deep pocked to retain the lash pad. I source from http://www.precisionshims.com.au/ in Melb, he's a nice guy (train spotter) and works out of his shed. Last set I bought was 8 different sizes to suit the rocket/valve wear (+- 0.01mm), they will suit whatever size you want. Changing the rocker pad geometry and integrating lash pads allows you to change the acceleration path of the valve sort of like re-profiling the cam without touching it. Just started working on a 12G940, have a set of 6mm OE valves I'll be putting lash pads on. Will be fun clearing the hurdles. |
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