T&D 1.7 rockers. Pushrod Clearance dramas
12-22-2003, 07:17 PM
#1
Staging Lane
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T&D 1.7 rockers. Pushrod Clearance dramas Guys, need some feedback.
Fitted some 1.7:1 T&D rockers for my 428CID build and found that there is no clearance for the pushrods in their passages through the heads ..they sit against the bottom of each hole.
The pushrods seem to be the right length but their angle into the heads is a bit shallow.
Is it safe to asssume that the heads require some additional milling to create the required clearance ? or Have we missed something basic here?
Hoping guys with these onboard might be able to clue me in on this. did you need to mill clearance?
Oh Well...another delay to a project that is WAY overdue
'Blowing out very heavily' about this ...spewing!!!
Fitted some 1.7:1 T&D rockers for my 428CID build and found that there is no clearance for the pushrods in their passages through the heads ..they sit against the bottom of each hole.
The pushrods seem to be the right length but their angle into the heads is a bit shallow.Is it safe to asssume that the heads require some additional milling to create the required clearance ? or Have we missed something basic here?
Hoping guys with these onboard might be able to clue me in on this. did you need to mill clearance?
Oh Well...another delay to a project that is WAY overdue
'Blowing out very heavily' about this ...spewing!!!
12-22-2003, 07:49 PM
#2
Launching!
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My understanding with the TD is that you need to make the pushrod passage in the heads larger. There was some discussion here prevoiusly on if you could just run a drill through them or have them machined.
The angle will change as the rockers sit higher on the mount hence the reason you need a clearance spacer for the rocker cover.
https://ls1tech.com/forums/showthrea...t=pushrod+hole
The angle will change as the rockers sit higher on the mount hence the reason you need a clearance spacer for the rocker cover.
https://ls1tech.com/forums/showthrea...t=pushrod+hole
12-23-2003, 01:44 AM
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I think visceral and I were one of the first to try installing T&D rockers on LS1 stuff years ago, and when we found out about the pushrod holes, we pulled the heads off and visceral took a drill with a big bit on it to enlarge the holes on his brand new $4k LS6 ported heads. It only took about half an hour to enlongate them some. I'm sure it'd go even quicker with a die grinder.
Only real downside is you'll need new bolts and gaskets if you didnt use reusable stuff. Oh, also, the T&D instruction sheet used to be incorrect for the rocker bolt torque specs. I'd probably say go with the GM spec of 22lb/ft.
Only real downside is you'll need new bolts and gaskets if you didnt use reusable stuff.
Oh, also, the T&D instruction sheet used to be incorrect for the rocker bolt torque specs. I'd probably say go with the GM spec of 22lb/ft.
12-23-2003, 02:31 AM
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Staging Lane
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Yep...looks like clearance is the concensus. I could see it but too late (I didn't install these things).
Just one more thing to be unhappy about I guess (the list is growing).
Just one more thing to be unhappy about I guess (the list is growing).
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12-23-2003, 06:03 AM
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Spacey.
check that the rocker is not binding on the p/rod. It is not uncommon for engine builders to "let" the pushrod "touch" the head to remove harmonics from it especially when using a poxy 5/16" pushrod.....
But if it is binding you are sunk. But hasn't that motor of yours been on the dyno?
check that the rocker is not binding on the p/rod. It is not uncommon for engine builders to "let" the pushrod "touch" the head to remove harmonics from it especially when using a poxy 5/16" pushrod.....
But if it is binding you are sunk. But hasn't that motor of yours been on the dyno?
12-24-2003, 10:19 PM
#11
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I found the same problem about a year ago when I was dummying up my engine.
Here's the LINK
HQ, this engine was run on the dyno with the standard rockers. The builder asked to use mine at the time. I told him they wouldn't work because of this and the fact that he needed the spacers. You got the call right?
When an engine is tested on the dyno, it's the sole responsibility of the engine builder and not the operator, to make certain things are correct. That's why you will find an assortment of mops and buckets just outside the door.
Sorry to hear about this Brian.
Here's the LINK
HQ, this engine was run on the dyno with the standard rockers. The builder asked to use mine at the time. I told him they wouldn't work because of this and the fact that he needed the spacers. You got the call right?
When an engine is tested on the dyno, it's the sole responsibility of the engine builder and not the operator, to make certain things are correct. That's why you will find an assortment of mops and buckets just outside the door.
Sorry to hear about this Brian.
12-25-2003, 05:20 AM
#12
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Originally Posted by Plan B
I found the same problem about a year ago when I was dummying up my engine.
Here's the LINK
HQ, this engine was run on the dyno with the standard rockers. The builder asked to use mine at the time. I told him they wouldn't work because of this and the fact that he needed the spacers. You got the call right?
When an engine is tested on the dyno, it's the sole responsibility of the engine builder and not the operator, to make certain things are correct. That's why you will find an assortment of mops and buckets just outside the door.
Sorry to hear about this Brian.
Here's the LINK
HQ, this engine was run on the dyno with the standard rockers. The builder asked to use mine at the time. I told him they wouldn't work because of this and the fact that he needed the spacers. You got the call right?
When an engine is tested on the dyno, it's the sole responsibility of the engine builder and not the operator, to make certain things are correct. That's why you will find an assortment of mops and buckets just outside the door.
Sorry to hear about this Brian.
I never expressed or implied that the problem could be associated with the dyno....my only reference to the use of the dyno was to query if there was a problem seeing as it had already done dyno time....
Yes I got the call...it was put to me that the engine builder had borrowed some spacer off you......I sold him some to replace your which I was told needed to be returned.
Sorry for the miss understanding.
12-26-2003, 03:50 AM
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Staging Lane
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Originally Posted by Plan B
I found the same problem about a year ago when I was dummying up my engine.
Here's the LINK
HQ, this engine was run on the dyno with the standard rockers. The builder asked to use mine at the time. I told him they wouldn't work because of this and the fact that he needed the spacers. You got the call right?
When an engine is tested on the dyno, it's the sole responsibility of the engine builder and not the operator, to make certain things are correct. That's why you will find an assortment of mops and buckets just outside the door.
Sorry to hear about this Brian.
Here's the LINK
HQ, this engine was run on the dyno with the standard rockers. The builder asked to use mine at the time. I told him they wouldn't work because of this and the fact that he needed the spacers. You got the call right?
When an engine is tested on the dyno, it's the sole responsibility of the engine builder and not the operator, to make certain things are correct. That's why you will find an assortment of mops and buckets just outside the door.
Sorry to hear about this Brian.
