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3K Or 4K Bore Pitch/ Spacing

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inlet is through the middle of the head, also each cam operates both inlet and exhaust valve... wtf again...

 

time to do some googling...

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  • was it this guy?             ohhhh, the engine had a strange head..... :blush:

  • camerondownunder88
    camerondownunder88

    NICE that 4k + 4age is AWESOME.   My guess is he still uses the 4K crank. 4age rods on a K motor crank have a few mm side play think 6mm total so I take it bore move was minor and the play in the ro

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Ah looks alot like the last generation repco brabham v8!

The waggot stuff could be found on an early Holden forum.

 

 

Stu.

Waggot heads were for Holden Grey motors

Waggot heads were for Holden Grey motors

Ha nice. Was that still a 8v twin cam? Ive seen a twin cam red motor head before, must have gotten mixed up with the guy in Qld that does or used to do twin cam heads for Holden and Ford 6's.

The best aftermarket t/c head for a mass produced engine I've seen is my mates KAD "a" series mini head. These things were massive in the 80's. Still has the pushrod camshaft to run oil pump and dizzy. Micks sports sedan is out of control! Revs to the moon and the 8" wide slicks help too. Think he has a class lap record at Phillip Island too. I will get photos when it comes back from the machine shop. Engines even crazy built ones don't last long spinning them to 11k lol.

 

Stu.

Ive seen a twin cam red motor head before, must have gotten mixed up with the guy in Qld that does or used to do twin cam heads for Holden and Ford 6's.

Stu.

that was krogdahl head.

 

I went to uni with his daughter for a semester, she told me about it originally, then i found it in a street machine mag i had.

 

small world.

if anyone is interested

I just fired up my latest experiment yesterday.

not tuned yet but idles and revs niceley

 

post-11347-018758400 1304418879_thumb.jpg

post-11347-082963600 1304419137_thumb.jpg

 

4k block+4age head

bored out the block by 6mm, had to move the bores around a bit to get them in the middle of the casting, still about 3mm wall thickness.

used 4age pistons and rods.

11.1-1 compression

quad 40mm cv carbs

also had to extend the camshafts by about 50mm and machine a block to hold all the bearing and seals ect.

all external oil feeds and drains

elongated head stud holes to suit 4k block

 

def NOT easy conversion, nothing is bolt on everything is one off machiened.

Phil

  • Author

Kudos for the engineering. I can;t wait to hear how it runs.

Wow.

 

That is the coolest thing I've seen in a long time! Big kudos.

 

Seeing that you've had to move bores around, what crank did you use?

Edited by snot35

NICE that 4k + 4age is AWESOME.

 

My guess is he still uses the 4K crank. 4age rods on a K motor crank have a few mm side play think 6mm total so I take it bore move was minor and the play in the rods took it up.

 

But I love that motor we need a dyno run of that see what the difference is. AWESOME

 

Engine of the year anyone..lol

 

Cameron

I don't get it. :blinks: Whats so good about the 4k block? Like, why would you do this other that just to be different?

 

Pretty damn cool though! And bike carbs! nomnomnom..

block says its still a 4k motor, so don't have to engineer it, would be the only real benefit i can see?

 

perhaps to stay in a certain class of racing?

camerondownunder88 is spot on. i used a 4k crank, but removed the side counterweights, knife edged, balanced and shot peened.

no real reason for keeping the 4k block just thoughi i would see how far i could take it.

ill put up some pics of the internals when i get a chance

Why not do it just for the challenge? An engine swap would have been easier and probably give more power, but a lot of people do them. Looking forward to as much detail as you're willing to provide :)

Edited by snot35

I got some more tuning done this avo, just about ready for a test drive. i think it is going to be thirsty, i have increased the jets from 130s that were good for the stock 4k and i am now running 210s and it is still lean on what.

it sounds amazing, a lot like a bike

 

here are some more picks of the internals that i promised

post-11347-060091800 1304583001_thumb.jpg

here is my crank

post-11347-007631600 1304583064_thumb.jpg

and a stock one for camparison

post-11347-075757900 1304583214_thumb.jpg

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