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My new YT head is on, ive got 10/1 comp (finally), and i fitted the rockers today. My old shaft mount rollers won't go on the studs, so it's stock gear for now.
The nuts, when a warm, running adjustment is done, barely reach the taper that locks them down. Basically i can't imagine they'll stay put under driving conditions. Is this common? I'll grab a new set of nuts, as it's a cheap experiment, unless some tells me otherwise? |
"Silly modern cars" |
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Hi Peter.
Something is very wrong there. Id be finding out why its so far out.
Are you using 202 pushrods ?
Dr Terry
_______________________________________ There are only 3 types of people in the world. 1. Those who make things happen. 2. Those who watch things happen. 3. Those who wonder what happened. |
If at first you don't succeed, just call it Version 1.0 |
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Evening Terry, hope youre well. Ive got 186 rods, but the head has been shaved a fair bit (40thou by us, plus anything Yella Terra did back in the day, the chambers now about 40cc and its a 161 head). So the rods will seem like theyre longer?
Maybe theyre not stock nuts? The old owner was missing two and had mild steel nuts doubled up on them. Ive found more suitable nuts but still not convinced. The "stock" nuts are concave one end, convex the other, and taper slightly on the thread, with three markings on the convex end outer.
About 1mm of the stud is above the nut.
Theyre 3/8 screw in studs.
I will be buying roller rockers, when i can sell my old head and rollers to cover costs. |
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Your probably running incorrect Lifters. Are they bleed properly?
If you are satified with the Pushrods, Lifters and Cam then you should consider getting a set of adjustable Pushrods.
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Standard Holden 6 hydraulics and they bleed and cycle fine. We need to work out why these rockers sit so high. Maybe the valve stems are longer? Theyre big valves, YT stamped exhausts. Intakes look fresher, may have been renewed. Valve seats are all new as i recond the head. |
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Thinking outside the square for a minute, could it just be that the screw-in studs are too short. If that is the case & your rocker arm geometry is somewhere near close, you could get away with a set of Posi-Locks. They are simple cheap & effective. I ran them on a 750 hp nitrous SBC for several years.
Dr Terry
_______________________________________ There are only 3 types of people in the world. 1. Those who make things happen. 2. Those who watch things happen. 3. Those who wonder what happened. |
If at first you don't succeed, just call it Version 1.0 |
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Thanks Terry. I was given a set of posi lock and was happy as larry, till i found they were 7/16, not 3/8.
Found out we took more like 60thou off the head. So that will "add" 1.5mm to the pushrods and make the rockers sit high. Thats quite a lot.
Options are, space the studs up a tad maybe, with a 1mm washer? Or try my 202 rods (which are two tenths shorter) and hope the geometry is fine? Find some posi-locks, or just stump for the roller rockers and be done with it.
Got some new nuts, they cost next to nothing, so thatll maximise the lock on any extra thread i can get. |
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A thought struck me today...hurt a little.
Seems i have late model rockers on this 186 head. Apparently there were kits for this back in the day? Theyre 173/202 style, rather than the narrow early style. Could that contribute?
New nuts were a HUGE improvement, to the point where theres minimal thread above the nut, but theyve got good tension, so im satisfied. |
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