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Registered:
May 2002
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Old skool - holden 186 and push rods/rocker Q's
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Mon, 06 December 2004 13:35
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I got an old torrie with a red 186 and triple SU's. I snapped some bolts in the head and couldn't get em back out. No biggie though, as I had a black 3.3L from a VK with a hole in a piston. So I drilled the water galleries in the red block, and modified the red manifolds to bolt onto the black head and bolted it all together.
My problem is, the red 186 and black 202 pushrods are different lengths. The red head had adjustable rockers, the black head doesn't. With the red (longer) push rods in, I fear the valves may be being held open. the valves seem to move a long way when I clamp the rockers down. I don't have access to a compression tester and cause of the design of the spark plug holes I can't get any fingers over the hole, but the compression doesn't feel too bad... the shorter rods are fairly loose and give the rockers a bit of play.
I could shim up the rockers with washers and use the longer rods which should work but I don't know how tight they should be. How much should the springs compress when tightening the rockers? I thought not at all (cause if the valve moves even a bit it'll open right?) but someone told me 1.5 turns on the bolt once the rocker puts pressure on the bolt.
Thanks for any help.
Tim.
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Location:
Armidale
Registered:
January 2003
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Re: Old skool - holden 186 and push rods/rocker Q's
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Mon, 06 December 2004 22:24
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Most of us old Holden types went the other way - put the older heads on the newer motors to gain the adjustable rockers  The other way is to just chuck the nonadjustable rockers and use the 186 ones, but you will need to put studs in the head where the bolts used to be - a relatively trivial task.
To adjust, I was taught to turn the crank so as to set the cam to 'closed' for the relevant valve (and you can do them in pairs, so there is only 3 crank positions needed). You then spin the push-rod with your fingers while tightening the rocker nut, until it just starts to get tight, but before it starts to push the top of the lifter in (assuming hydraulic lifters). You then tighten a further 3/4 of a turn and lock it off.
It your case, I guess if you have to turn the bolt more than 1 turn after it hits the lifter (for a valve that is meant to be closed) to get it tight, then you need shorter push-rods. Getting ones the exact right length might prove practically impossible; I'd be going the adjustable route if I were you  ...
Cheers,
Adam.
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Registered:
May 2002
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Re: Old skool - holden 186 and push rods/rocker Q's
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Mon, 06 December 2004 22:37
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nah I wanted the better flowing head and I want to put the efi on it later. I perhaps could've used a blue head, but I don't know if they are adjustable or not... Besides, I had a black motor sitting there.
I hope people aren't retro fitting the red head to anything, That is such a peice of shit, even to 1970's standards...
Tim.
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Location:
Armidale
Registered:
January 2003
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Location:
B risbane
Registered:
November 2004
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Re: Old skool - holden 186 and push rods/rocker Q's
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Mon, 06 December 2004 22:57
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If you want stronger con rod's you can modify VW or BMW rods to fit, They're supposed to be heaps stronger than stock Holden rods. If you want performance piss the old Holden six off and stick a 1G or 1J in it. That would really upset the purists 
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Registered:
May 2002
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Re: Old skool - holden 186 and push rods/rocker Q's
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Tue, 07 December 2004 00:09
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sure a 1G or 1J would be nice, but the 186 bolts in and with the triples, it goes damn hard. Responsive like you wouldn't believe. Doesn't like revving much over 5K though, and chews fuel like a bitch. But I think the sound of those carbs sucking up rivals the turbo whistle on my old celica...
I'll have a look at the heads today and see how much is onvolved with swapping the adjustable rockers over. That's a pretty good idea.
I think the rods will be fine for now, If I was going that far I'd put a 1G in it  This is just for fun, cause I had all the bits in my shed...
Tim.
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