11/32 valves in X heads

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65cuda360

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I picked up a set of X heads that had a half done valve job. They are bare, and have had the seats replaced, but not cut, and the guides are sleved down to 11/32nds. My machinist is putting in chevy valves. With the stock 3/8 stem valves being 4.980 length and the chevy stuff being 4.911, is my only option a longer pushrod, or do I need to get 273 adj rockers and shafts? I asked about getting the + .100 chevy valves and grinding the stem tips, the machinist said it wouldn"t work... How do you adjust valve lash on a hyd lifter with the motor running?
 
on topic answer:
you dont on a mopar. you set the .030 preload prior to running the engine.

off topic question:
why exactly was there a need to go with chevy valves?

EDIT**
what crackedback said...
 
What other valves are 2.02 and 1.6 with 11/32 stems and don't cost $25 EACH......with the correct length of 4.980? This is just a mild street motor, and trying to keep it low buck.
 
They make long Chebby valves that work for this. Had some put in my 302 Swirl port heads. Have to look at the invoice again for cost... Ditto on the machinist comment. You must grind stems on a mopar to set the height.
 
I kind of suspected that he was wrong about the +.100 chevy valves. When i asked about them, the answer he gave was that the assembled height would never be right,if the stem tips were ground down the rocker would hit the retainer and not the stem tip.
 
fishy68 said:
Exactly. There's no reason at all a +.100 long Chevy valve wont' work. Your machinist is a dork.
Click to expand...

BJR put those in my INDY/RHS X HEADS and they did not work there either. What a JOKE that nightmare is!!!

I agree with Crackedback!!!!!! RUN AS FAST AS YOU CAN & FIND A NEW MACHINIST!!!!!
 
65cuda360 said:
I kind of suspected that he was wrong about the +.100 chevy valves. When i asked about them, the answer he gave was that the assembled height would never be right,if the stem tips were ground down the rocker would hit the retainer and not the stem tip.
Click to expand...

A +.100 Chevy valve is only .031" longer than a stock Mopar valve. That's not much diff. I didn't measure is but I'm sure there was alot more than that on most of the heads I assembled. I only had a couple cases where some aftermarket rockers hit the retainers and that's because I was using larger diameter than stock retainers and aftermarket rockers. Stock parts has alot of clearance.

BTW: I just noticed you said the heads have new seats. If that's the case it's very possible that the +.100 valves will work perfectly without even grinding any off.
 
I checked with the machinist today, he was working on my heads when I walked in. He did get the +.100 chevy valves. He said there was d difference in the assembled height between the intakes and the exuast. He said the exuast looked ok, but the intakes were coming in high, more then he wanted to grind off the stems....anybody got some adj. rockers and shafts for sale?
 
Mad Dart said:
BJR put those in my INDY/RHS X HEADS and they did not work there either. What a JOKE that nightmare is!!!

I agree with Crackedback!!!!!! RUN AS FAST AS YOU CAN & FIND A NEW MACHINIST!!!!!
Click to expand...


Sorry BJR told me he used .100 longer valves but I have even WORSE news HE STRAIGHT OUT LIED TO ME the valves he used are 3/8 of an inch taller than stock. NO WAY TO EVER GET THE GEOMETRY CORRECT WITH THESE VALVES BEING THAT TALL AND MACHINING, DRILLING AND TAPPING THE STUDS AT DIFFERENT ANGLES, CROOKED AS A DOGS HIND LEG TO BE EXACT!!

A FULL TUTORIAL ON HOW NOT TO DO MACHINE WORK WILL FOLLOW WITH PICTURES VERY SOON ON A NEW THREAD!!!!!
 
360, I've used them before for both cost and the smaller stems. Truthfully they are all the same price now when you're looking at lower cost performance lines... But Magnum stuff they get used in. If your valve stem heights are off even tho the seats are correctly placed, you can cut the stems. You just have be aware of the lock and where the retainer ends up. Meaning you can't whack a ton off...lol
 
moper,
smaller stems for flow.. gotcha. but that would require a very compantant machine shop to do that.. especially for all the valve guides..
maintaining geometry and such.
 
Geometry is a diff subject, for it's original accuracy is based on stock lifts from the factory.

Once the lift/base circle changes, time to start over on the geometry part.

stem heights are cake, serdi valve job ,well...it centers itself , and if somethings off it cause you bumped it before the table air locked .lol
 
Mad Dart, I understand you angry but can you keep it in one thread please?
 
No problem, Speak your mind and leave a link to your thread if you wish. Just make sure you update your thread with pictures and proof.
 
there is a problem with changing the lenght on the valves in j / x heads.. since the stems dont stick straight up, if the valves r bit longer u will "need shorter rockers" witch u dont have.. there are these adjustable stainled rockers that gives good room for retainer and a bit grindable:

http://cgi.ebay.com/ebaymotors/MOPA...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

in anny case u will need to make sure that the roller dosent hit the valve stem to far out, it should be in the middle in ca half of the lift.. even if they are adjustable and u could grind room for the retainer.. incorrect geometry will make the valvetrain suffer. link below is a nice way to study it :p


http://www.compcams.com/Technical/FAQ/ValvetrainGeometry.asp

hope this helps

Jo
 
Norway, the fix is to mill the rocker stands down flat and use shaft support blocks like the W2 long valve heads. Then you can position the shaft up, down, forward, or back as needed.
 
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