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L18 block questions


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#61 Stoffregen Motorsports

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Posted 03 December 2017 - 08:18 AM

what do u mean by fully counter weighted? and it is! took it all apart and took it to an engine shop and they said its bored 40 over with 280z flat top pistons

and why move it? it has headers already and it was left in the same place

The crank in the pic shows that it has counterweights on only half of the crank throws. The early L18 cranks had counterweights on all of the crank throws. It makes for a smoother running engine.

 

I can't tell from the pic, but in most cases, those Z blocks had an angled pad of material on which the ID was stamped, and the angle makes it impossible to fit a header (without mods). If you say that it does fit, then ok.

 

Why move the dipstick? For easier access and a more appropriate appearance. L motors had them on the pass (right) side.



#62 Stoffregen Motorsports

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Posted 03 December 2017 - 08:21 AM

I run an OS Giken 7-lb flywheel with a twin plate all metal clutch on my 620.

It's like an on/off switch.

I've leaned to drive it just fine, but few others can.

I call it theft prevention   :)

 

IMG_2649.jpg

 

The place that does my state inspections doesn't even try any longer, they just check the lights, and hand me the receipt. 

Back when I first started playing with L4s, I machined one down to 20-lbs, and even that was a big improvement.

Those multi disc clutches are definitely hard to drive. If you've got it figured out...cool.



#63 G-Duax

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Posted 03 December 2017 - 08:53 AM

The thing is, that from just barely starting to engage, to 100% hooked up is only about 3/16" of pedal movement, if that.

Once that sunk into my old feeble brain cells, things got a lot easier. 

 

I'm thinking a smaller bore master cylinder would help a bunch.

When the old engine comes out, it's getting a Quartermaster hydraulic throw-out.

Now you are supposed to use a 3/4" master with them, but I'm going to leave the original 5/8" in the truck, and see how that works.

Because, I still stall it once in a while when 50 years of manual clutch experience overrides the newly learned skill.

 

DSC08185.jpg



#64 Stoffregen Motorsports

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Posted 03 December 2017 - 09:30 AM

Those throwout bearing assemblies are known for being hard to bleed and also for not returning allt he way, all of the time. I know it's a race proven design, but it is not maintenance free.

 

Give yourself a head start and extend the bleeder on a AN hose so you can reach it when you need to bleed it.



#65 wayno

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Posted 03 December 2017 - 10:33 AM

So your supposed to point that at the hole where the arm normally comes out?

Have they ever jammed and spun inside the bell housing or does it connect to the arm ball like the arm does?


 

 


#66 G-Duax

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Posted 03 December 2017 - 11:55 AM

The top hose in that picture is the bleeder hose. Had to do that so the bleed port was on top.

Took forever to find that damn fitting :(

 

Wayno, yes on this one, I pointed it out the original clutch fork hole, and locates on the original ball location.

But it had to be cut down, and a shcs takes the place of the ball.

 

DSC08186.jpg

 

Also, the ID of the US trans intended throw-out was too large to fit the 71B snout, so it was sleeved.

The throw-out was used, off eBay, so it was completely disassembled, had new seals, and a fresh bearing installed.

Weird thing is, Quartermaster used a metric bearing commonly found on Toyotas.

Pretty sure that if the bearing ever goes bad, that I will hear it before it ever comes close to locking up.

 

I'm doing an S15-R 6-speed into a Toyota right now, and using the same throw-out.

But because the 6-speed snout isn't hard chromed like the 71B, just bare aluminum, so I'm bonding a steel sleeve over it, instead of in the bore of the throw-out.

Since the Toyota conversion is using the Toyota auto bell housing, I can just about point it any direction.