Engine loses power under load. WTF??

[Rothu]

Ok, got another set of push rods, pulled out the old ones, Bugger me they were bent!
Installed the new ones, BINGO!! Power is back! One very happy camper! 
Thanks for all your advice guys!

[Marishka]

good 2 hear,
i bet the compressions good on all cylinders now?

post some pictures of the bent pushrods, be cool 2 have a look.
 

[ben]

cool as! good to hear!

ben

[MaTTe]

hey mate, good to hear you've got it sorted!
I thought about the push rods when i first saw the thread, but i couldn't see how they'd have been bent by blowing a head gasket.. so i passed it off as something else..
Goes to show, you need to look at all the small things..

Well done!

[Marishka]

sounds like ur tappets were tightned down 2 much resulting in the pushrods bending when the lifters pumped up with oil resulting in valves not closing properly causing power loss.

161,173,179.186 heads have fully adjustable tappets and u can run into this problem by not giving enough clearance.( tightning them down 2 much)

(ask ben about bending pushrods and what causes it.
he had a bad expereance with them 2 on maria,s van.
and the pushrods bent and smashed through a few tappets. )
 
but 202 heads its hard to go wrong as the tappets are non adjustable and bottom out when the rocker gear n bolt is tightned down solid.

only way u can go wrong with a 202 head to block surface is ground down heaps. could need a shim spacer between the rocker gear post n rocker bolt hole surface.

[able]

i would be having a look see in a week... if the new push rods are the same size then you have fixed the symptom.... not the problem.

they didn't bend because they thought it was a good idea so logic tells you that you are on the road again but will be back in trouble in roughly the same time it took the other ones to bend.

that's what would be going through my mind.

[ben]

good thinkin able:))

[Rothu]

Guys, this is what I've worked out the history of the bent rods.
It's a 173 head with NON-adjustable rockers which I got from ebay. it was totally recoed by Repco, but they did a pigs breakfast of it.

When I blew the head gasket, I had the head checked and then forked out to have it totally recoed again... The valve stems weren't "falling" naturally, needing a valve stem guide regrind.
THAT'S where the rods bent, trying to open up valves that were sticking.
I got new hardened push rods and it just jumps up and goes now!
Up a wall in 5th gear? No problem!

[Marishka]

sounds like a bad reco first off.
who did the second reco?
non adjustable rockers on a 173 never heard of them before.
got any pictures u can post up?
or can u give the ebay item number? ( might be able 2 see from the item pictures)
im interested 2 see the rocker setup.

[Rothu]

The first photo show the first head with receded valve seat on the exhaust on No.1 cylinder.
It was a 202 head with adjustable rockers. I checked the casting number and it matches. 2811930
the next 2 show the one I bought, the guy thought it was a 202 head, but it was a 173 HC head!
Again matched the casting number. 2811929
here's some links that I found to help match the casting numbers.

http://oldholden.com/node/78628

http://www.allhead.com.au/Identification/ID_Red%206.html