Harv's Repco HighPower crossflow head thread

[sgo]

Is there any oil supply to lube rollers and top of valves?

[Harv]

From what I can see, the rollers and valve stem tips are splash-fed.

Cheers,
Harv

[Harv]

ARP fasteners arrived, so went to fit them. Could not get either of the exhaust or inlet shafts to bed down. Lots and lots of fit and fiddle, and paranoia that I was doing something wrong. Finally realised that the heads are hand finished, and the angles for tapping and drilling may not be exact. The results of all that fit and fiddle tell me that for my particular head:

a) for the inlets, the shaft has to be in place and then the studs screwed through it, and
b) for the exhausts, that pedestal bolts need to be started before the pedestal/rocker cover studs are started.

All good - it all fit neatly, nothing tight or binding where it shouldn't. Gave up waiting for the 1/8 NPT plugs to arrive, so took the supplied long ones and ran them partly down a die. Refit to exhaust rocker shaft, see if they are flush, then die them some more until the are. Plugs now flush and not fouling rocker cover. The outer two exhaust pedestals do slightly foul. A smear of yellow paint, rocker in place, gentle tappy tappy then check the rocker cover for where the paint is rubbed off. Die grind a little, then repeat the paint check until it no longer fouls.

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Think I am about there. Fit to engine:

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Next step: pushrods.

Cheers,
Harv

[Blacky]

That is a thing of beauty Harv

One of our club members has one and he is making noises about selling it - its out of me budget but if he decided to move it on you will be the first bloke who knows about it

[Errol62]

Come on Blacky. Need one on the yoot.


FB ute fixer upper, EK van on rotisserie

[Harv]

Today, pushrods. Almost.

Knew the pushrods were too long for the rollies, so didn’t fit them when I put the head on. Need to measure, then get new ones made up. Somewhat frightened, as they are NOTHING like a normal pushrod. They need to be custom made from 1/4” silver steel rod, then heat treated. Preparing for a wallet-dectomy

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Figured I could screw the rocker adjuster out, slip in a pushrod checker, then refit the adjuster. Good in theory, not in practice - adjusters only come out downwards. Rocket gear off. I had bought a ball-end pushrod checker years ago, and managed to put it aside when I packed the shed up.

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In theory, fit the checker and rocker gear, screw the checker out (with a feeler gauge holding roller tip lash at 14 thou) and then get the new pushrods made up to that length. Slight problem: the checker I bought years ago does 9.8-10.8”… and I need about 8” for the exhaust and 6.5” for the inlet. I could cut some rod down and fit, cut, fit, cut but all that gear is now packed away with the shed, and my patience for refitting rocker gear a dozen times would grow thin. Two new checkers to suit on their way.

The next learning was that the rollers are made for 5/16” balls, and the lifter end cups are made for 1/4”. The cups are an insert fit into the standard lifter, once it has been recessed a little. If I get the cups milled to suit a 5/16” ball then I can use standard type pushrods. Lifters back out and off to have the buckets milled.

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Cheers,
Harv

[Blacky]

Come on Blacky. Need one on the yoot.

Can't justify the cost mate - the Holden grey motor is surpassed only by the flathead frod on the wrong side of the dollars in to horsepower out equation I could do a LOT of stuff to the 2 door with what I would spend on a Repco head for the ute......

[Harv]

I can see why the red motor so quickly overtook the grey. To get 200hp out of a grey reliably costs an arm and a leg.

This exercise will be worth it in the end, but there are times when I wish I could shop a catalogue and bolt up like you can with a SBC.

Cheers,
Harv

[Harv]

My search for a genuine Repco HighPower head has been unsuccessful, despite several years of chasing . I am now committed to a repro head, and have paid the deposit. In getting to this decision, I’ve done my homework, and will share the results below. Have tried to chase down the Chinese whispers, which has led to a lot of calls to some very interesting people (and managed to talk to the owner of two Normans that I did not previously know of). Talked to quite a few guys who either currently own, or have previously owned factory heads. The community is small, but very knowledgeable. Their time on the end of a phone has been appreciated.

Reproduction Repco HighPower heads have been made by Rod Scheffler in both aluminium and cast iron. Ballpark costs are $14k for an iron head, and slightly more for ally. This includes all the running gear (valves, rockers, rocker covers etc). Around 10 have been sold so far. I am going a cast iron head, as it "feels" more period correct, and will probably take a bit more abuse than the ally. This will be no show pony... I intend to make it earn its keep. Will probably have to sell on some other toys to make up the dollars.

The heads are supplied with ally roller rockers. No-one currently reproduces the factory type rockers. Terry King can supply rocker adjusters, posts and shafts. He made a run of 10 reproduction rocker arms, though no longer makes them. The factory Repco rockers have geometry issues (the exhaust valves unseat from the rocker tip at high revs), though can be successfully reworked by Ian Tait and survive up to 8,000rpm. However, the original factory rockers, based on Vincent parts, are rarer than rockinghorse poo. John Anderson made a run of 10 steel roller rockers, though no longer makes them. All up, the only currently available set of rockers (of any type) for a Repco head are the ally rolly rockers made by Rod.

It will be a few months before the head is ready. I still have quite a bit of work to do to get the bottom end of the meth monster together ready to receive it.

Finally, some movement on my repro head. Head has been finished, and I've made the final payment on it.

I end up with an ally head, valves, springs, retainers and collets, rocker cover, sideplate, breather pipe, lifter inserts, head/rocker/exhaust gaskets and head studs. Rockers will be made by others, so still some work to go.

Cheers,
Harv

[Blacky]

That was quick - only 6 years ago !