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914World.com _ 914World Garage _ what chromolly push rods?
Posted by: shaggy Oct 10 2006, 12:50 PM
im changing to chromolly push rods to do rocker arm geometry
i noticed on the aircooled site they offer several different ones.
what ones do i want:
what diameter?
with or without taper?
thanks
-jim
Posted by: Twystd1 Oct 10 2006, 01:50 PM
stock cam or big lift cam.
twystd1
Posted by: Aaron Cox Oct 10 2006, 01:56 PM
i went with manton chrome-moly's and i think they were 3/8
Posted by: Jake Raby Oct 10 2006, 02:11 PM
http://www.aircooledtechnology.com/store/product.php?productid=16237&cat=285&page=1
When you lose a tip from one of the imitation pushrods you'll see why these are all we use..
I have used thousands and never had a bad one, I have bent TWO of them in the past 8 years...
Posted by: ChrisNPDrider Oct 10 2006, 02:53 PM
Jim - DID YOU LISTEN TO THE IV DIMENSION radio show? Oct 6 was valve train. That's all I can say...be an INFORMED buyer 
Posted by: thomasotten Oct 10 2006, 03:00 PM
So with these, you get the car hot, then adjust? How about the first time you are installing, how do you adjust the clearance?
Posted by: bd1308 Oct 10 2006, 03:02 PM
zero lash, you want the push rod to move by some method and thats it.
Posted by: Aaron Cox Oct 10 2006, 03:14 PM
nope. when dead cold.. you set it to ZERO lash....
steel doesnt expand as much as aluminum....
so when the motor is nice and hot, and the aluminum expanded... and the steel pushrods havent, you have a few thou of lash when hot....
just right...
Posted by: Jake Raby Oct 10 2006, 03:28 PM
Jim - DID YOU LISTEN TO THE IV DIMENSION radio show? Oct 6 was valve train. That's all I can say...be an INFORMED buyer
yep- thats the best 1:22 minutes you can spend!
Posted by: blitZ Oct 10 2006, 04:17 PM
So, when you adjust your valves with these pushrods, you use zero clearance intake and exhaust? Excuse me, I'm a little slow.
Posted by: Aaron Cox Oct 10 2006, 04:30 PM
So, when you adjust your valves with these pushrods, you use zero clearance intake and exhaust? Excuse me, I'm a little slow.
YEP.
with mantons and a header, i did a valve adjust in 7-8 minutes
Posted by: blitZ Oct 10 2006, 05:37 PM
So, when you adjust your valves with these pushrods, you use zero clearance intake and exhaust? Excuse me, I'm a little slow.
YEP.
with mantons and a header, i did a valve adjust in 7-8 minutes
Great, guess I'll have to get a new feeler gauge. Mine doesn't have a zero.
Posted by: Joe Ricard Oct 10 2006, 05:51 PM
So, when you adjust your valves with these pushrods, you use zero clearance intake and exhaust? Excuse me, I'm a little slow.
YEP.
with mantons and a header, i did a valve adjust in 7-8 minutes
Great, guess I'll have to get a new feeler gauge. Mine doesn't have a zero.
That's pretty funny. mine does.
Actually zero lash is a bit of a misnomer. More accuratley for the "slow kids"
no perceptable slop when moving rocker are against valve and push rod. BUT you can still rotate the push rod with your finger tips.
OK that is zero lash but also how you achieve it.
Posted by: thomasotten Oct 10 2006, 08:55 PM
Ok, so let's say you install these, and then you sell the car. The new owner, not knowing anything about them takes them to the local "vw" shop. They adjust the valves using the old method, with a feeler guage, when cold. Won't the engine run like crap for that person? Would they ever figure out that these aren't normal push rods?
Posted by: Aaron Cox Oct 10 2006, 09:13 PM
Ok, so let's say you install these, and then you sell the car. The new owner, not knowing anything about them takes them to the local "vw" shop. They adjust the valves using the old method, with a feeler guage, when cold. Won't the engine run like crap for that person? Would they ever figure out that these aren't normal push rods?
or you could disclose the fact when selling
who cares what the NO does? lol
yep, their engine would clack all over the place and have like 9-10 tho clearances LOL
Posted by: anthony Oct 10 2006, 09:24 PM
I'm guessing that at least it wouldn't damage the engine.
Posted by: thomasotten Oct 11 2006, 07:31 AM
Perhaps someone could design a warning sticker that goes on the valve covers. WARNING! - ACHTUNG!
Posted by: Jake Raby Oct 11 2006, 07:35 AM
I have those stickers for my engines..
Many people still stuck in the 70s run their lash at stock settings even with these pushrods..
Its just loud and loses about .050 of the valve lift to lash and takes some valve duration away...
Not optimum..
Posted by: Matt Romanowski Oct 11 2006, 07:45 AM
What I would be more concerned about is the fact that you get .004-.008 lash (from Jake's page). That seems like a pretty big variable. Granted, I've never checked Al. ones when hot to see the difference.
Posted by: Jake Raby Oct 11 2006, 08:44 AM
The difference is the same with stock..
be more concerned when the engine runs over temp and the lash completely closes- when that happens valves burn, seats drop and even the heads of valve weaken and snap off...
Excess lash loses power and is loud, but it'll never compromise your engine. Not enough lash will open the wallet fast.
chromoly pushrods could be considered an insurance policy, when you over temp the lash opens up....
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