Doing some stupid shit to an old datsun head

[dat2kman]

What brand oil pump was it that exerted pressure on the drive spindle that then rooted the crank drive gear?

[hoffman900]

Tony,

I've seen similar modifications go from 36* of ignition advance to 27-28* (same size bore and fuel type).

The nice part about this stuff, is that if you are so inclined, you don't have to rev the engine higher to make a ton more power. Mods like this improve the efficiency of both the ports and the combustion process. It's a win-win all around.

[Babalouie]

Yup, if you're gonna get ping you'll get it 1st around peak torque, be carefull, if you can hear it it's more than a little ping!

Hmm...if I hear some ping at 28, I'm now thinking maybe I dial it back a little further, from 26 to say 25 or 24.

That would probably to too little advance at the bottom end, but I do have a locked-timing distributor I could use. Then it'd be 24BTDC all day.

[MRMOPARMAN]

Hmm...if I hear some ping at 28, I'm now thinking maybe I dial it back a little further, from 26 to say 25 or 24.

That would probably to too little advance at the bottom end, but I do have a locked-timing distributor I could use. Then it'd be 24BTDC all day.

She would struggle to turn over with 24btdc when trying to start I reckon.

[Babalouie]

Good point...MSD do make a box that 'tards the ignition 10deg during cranking tho

[Billzilla]

Good point...MSD do make a box that 'tards the ignition 10deg during cranking tho

Put something like a proper optical ignition kit into it. Full mechanical advance and maybe vacuum as well. It'll look exactly the same from outside and work a hell of a lot better.

[Babalouie]

Doing some stupid shit to an old datsun head

Put something like a proper optical ignition kit into it. Full mechanical advance and maybe vacuum as well. It'll look exactly the same from outside and work a hell of a lot better.

Current setup is Hall effect electronic dizzy, recurved by Stewart Wilkins (14deg mech advance all in by 2700)...the locked-timing one is a nice Kameari Engine Works one that is optical tho

[Gammaboy]

Current setup is Hall effect electronic dizzy, recurved by Stewart Wilkins (14deg mech advance all in by 2700)...the locked-timing one is a nice Kameari Engine Works one that is optical tho

These guys do a USB programmable unit (it's all inside the dizzy) - by playing some tricks with the ignition timing around idle you can stabilise the idle during warmup.
http://www.123ignition.nl/products.php

They don't list nissan/datsun, but an email is free - modifying one of the other 6cyl units might get you there.

[Xnke]

At 650$ US, the 123 dizzy is spendy. I can't find a single person using it on the Datsun, though the US distributor seemed keen to try selling them on Hybridz.

[Gammaboy]

There's a few guys using them over on the Alfa forums - they love them, and I'm > < this far off pulling the trigger on one.
Spendy? compared to a flogged out stocker that needs rebuilding and can only be curved to what the bobweights and springs can let you do? sure.
Compared to other fully programmable options?

[Lurch]

Lots of MGB owners are using them too - becoming very popular.
I might look at one for the Bugeye...

There's a few guys using them over on the Alfa forums - they love them, and I'm > < this far off pulling the trigger on one.
Spendy? compared to a flogged out stocker that needs rebuilding and can only be curved to what the bobweights and springs can let you do? sure.
Compared to other fully programmable options?

[TK]

Currently at 237hp @ 7250rpm, still tuning.

[Supercrown]

Hey tony, has the compression gone up from what it was previously?

It's 14:1 now - before was?

Just curious about the reduction in ignition advance requirement.

Is all of it attributable to the chamber shape, or can a compression increase be responsible for some of the reduction?


The head for this motor looked fantastic in person. The pictures really don't do it justice.

One of the most impressive of Tks skills is his fine motor control and repeatability when doing the grinder work on ports and chambers.

Anyone can learn to set up a mill, tip grind a valve, cut seats, put stuff in a lathe, use a torque wench etc etc. The difference with the hand working he does is that it has literally taken hundreds or maybe thousands of hours to have developed the fine motor control to where it is now.

Where i have noticed it most is not so much his ability to make a single port or chamber nice, but the ability to do one to the shape dictated by the flowbench and then proceed to copy that across the remaining 3, 5, 7 cylinders. He does this without anything more than a set of simple point feelers to spot check port width here and there and a junk pushrod to check that a wall is flat - (Which it usually is to within less than a mm already).

The big cathedral ports on the ls heads are where his ability to get them totally flat is crazy. I use his grinder and his cutters, but anytime i try to get something flat it ends up looking like the surface of the moon. Plus he's usually come over for a look and laugh at me as i feather the throttle like a 7yo on a trailbike.

In addition he'll also do stuff that nobody else will. Case in point was a split bore in a 2004 or so m3 block.

Whilst i was there last year incomptently using his machines to make some crown parts, i watched him patch the big vertical crack with 'stitching plugs' (which i'd never even heard of before), then order the sleeve.

As the sleeves themselves apparently vary in diameter he couldn't set the boring machine up to get the 2thou clearance until he'd measured it. Once the sleeve rocked up he measured it and from there he bored it out, and then jammed the sleeve in.

That was all good, but it was then evident that the adjacent bore was also cracked, so the process was repeated again. I was able to assist with some hammer blows as that's all he would let me do lol.

Of course 10+ stiching plugs in two adjacent bores and two sleeves belted in meant that the okay bores adjacent are now out of round as well, so all 6 bores were then given a final 0.5 mm overbore.

Finally, to combat future cracking the block was then given a partial grout fill.

From memory this took a day and a bit, but no longer than that. I did help, but my half a dozen hammer blows and dodgey plastic funnel for getting the grout in was the grand extent of it.

I've been fucking around with cars since i was 15 - which is 25 years now, but i regularly see Tk doing stuff that I've either never seen in person or never even heard of before. Whilst there are blokes on here that have seen it or done it, they are very few in number and generally in their 40s at minimum. Sadly as well there are virtually no young people learning this stuff.


END WALL OF TEXT

Cliffs
SUPERCROWN 4 TK 4 EVA

[TK]

LOL, cheers man, see you Saturday!

PS - figuring from # of port jobs done & average hours per job I figure I've spent about 8000 hrs on the grinder......

[TK]

Still waiting on more numbers, but 237hp @ 7250 = 116% VE, getn er done!