Hey!,

Thought it might be a good idea to collate some specs/pics and knowledge of the early type mechanical rocker heads,

There's a few cool projects going on at the minute, and have recently seen a spec (in my build thread) that excited me!

What have you got going on? Or what is your planned spec? Pics would be nice.

Cheers

Nothing to flash here. I have got Erics old 54k HK engine out of his coupe. He brought it to VW Action for me in his drivers footwell the legend haha

Parts collected so far....

Dbilas inlet manifold

Twin Weber 40 DCOE

90mm Jenvey trumpets

Mega jolt standalone ignition

Ashley 4 branch

Coming soon

Newman 284* Camshaft

Anyone any idea of what power it would make? I'm not chasing figures. its more about how it looks for me but a rough idea wouldn't hurt.

Weber 40 + Dbilas inlet by Winstang, on Flickr

Megajolt Ignition by Winstang, on Flickr

So i will start!

I've started build a 1400cc unit, using the HK mechanical rocker head;

Spec inlcudes (in some cases will inlcude);

>1393cc ABD Crank

>ABD Pistons (1.7mm Removed from top face, valve pockets re-machined)

>ABD Block (1.7mm removed from deck, coupled with pistons gives a 12.1:1 CR)

>284* Newman camshaft - 9.6mm of lift

>Newman followers

>HK Cylinder head - Standard valve sizes but "back cut" and reduced protruding neck diameter,

Will also have moderate port work, increased throat venturi etc (Needs new guides)

>ZXR400 Motorbike carburetors

>Home brew stainless intake manifold

>Shared intake plenum with cold air feed - (At some point)

Pics of head;

Pistons;

Block;

Crank;

Will update when progress is made....

Edited 12 December, 201213 yr by MaxGT

You both have my engines haha. Look forward to this is max ever makes his mind up

You both have my engines haha. Look forward to this is max ever makes his mind up

I've only changed my mind once!

Fucking love early engines <3

The faint tapping is what makes them sound mint!

They shouldn't tap with the correct maintenance/adjustment though :-)

Slightly related question: I'm building up a GT engine, lightened and balanced crank, fly, Ported head etc. Would it be worth sourcing some solid lifters from an early engine to replace the hydro ones in the GT? Would they pop straight in, or would i need to do some fettling? And would the gains be worth the effort?

Piper make solid lifters for them

They'll still tap a bit, just nowhere near as badly as when they're set wrong lol

Can we keep this setups or plans etc. Not random un related questions & chit-chat

Cheers

I set up the clearances with feeler gauges and it was still pretty tappety hence me swapping for a hydro engine. Did rev up nice and quick tho.

Edit- just seen your post.. How is talking about solid lifters unrelated to solid lifter lumps? Quit bitching man

Edited 12 December, 201213 yr by erixtar1992

http://www.flickr.com/photos/winstang/8208941760/

Awesome, how much they set you back? And where from etc

That should make a huge improvent over the standard set-up no?

Edited 12 December, 201213 yr by MaxGT

If I need to trundle these plans out again

>Rebuilt ABD bottom end

>Skimmed, Lightened and balanced ABD crank and pistons (to drop C:R)

>HK flat faced head

>GK cam

>GK inlet

>Standard dizzy with vac/boost pot

>Double valve springs

>Single barrel Solex R5T carb

>T25 Turbo

>Log type T25 exhaust manifold with 2.5" down pipe

>Bailey dump valve

>Focus ST FMIC

>Custom boost piping

Edited 12 December, 201213 yr by prankstar2003

I won the megajolt on ebay for £200. The main reason of buying was to get rid of the dizzy out of the engine bay and I can hide the coilpack on the back of the block. It should run the best it can run ignition wise. The past spark problems with the turbo lump also made me go for this set up.

I love the tap <3.. I think you should post your engine up Arun.

If I need to trundle these plans out again

>Rebuilt ABD bottom end

>Skimmed, Lightened and balanced ABD crank and pistons (to drop C:R)

>HK flat faced head

>GK cam

>GK inlet

>Standard dizzy with vac/boost pot

>Double valve springs

>Single barrel Solex R5T carb

>T25 Turbo

>Log type T25 exhaust manifold with 2.5" down pipe

>Bailey dump valve

>Focus ST FMIC

>Custom boost piping

Simon do you know if the inner spring from the GT heads can be used in the HK heads? Giving you double valve springs?

I won the megajolt on ebay for £200. The main reason of buying was to get rid of the dizzy out of the engine bay and I can hide the coilpack on the back of the block. It should run the best it can run ignition wise. The past spark problems with the turbo lump also made me go for this set up.

I love the tap <3.. I think you should post your engine up Arun.

Gonna have to invest for the next project i think,

I cant wait for a certain someone to post there spec/plan up

Not sure Max, I don't have the springs to hand. You've had the head to pieces, do the hydro springs look similar?

I didn't bother to look as i assumed not!

I just wondered as your spec quotes double valve springs :-)

Yeah, but I don't have them yet. I'll check when I get them

Why do all the mech cams have longer durations than the hydros? Is it due to them being more for race engines, or is there something in the valve train design that means durations have to be longer to match the hydro durations for performance? I have seen several mech cams in excess of 300 deg but nothing longer than about 280 for the hydros

Was wondering that too. With solid lifters in a hydro can u also get over 300 degrees?

Its great to see that people are still improving the really early engines. I've run lower powered ones in both mk1/2 and found they always leaked oil like no tomorrow which put me off keeping the HH in my Derby. Could never get the rocker cover leak free on any of mine, it always resembled the Exxon Valdez under the bonnet.

Isn't generally a lairier cam = you'll be revving higher & hyd tappets ideally only good for ~8k?

Well going on the dimensions of the HK cam it has a longer duration but smaller lift than the hyrdo heads.

Cams duration is measured in the amount of crankshaft degrees the valves are open, so it cant be anything to do with the different design of valvetrain.

Its a weird one!