l24 blocked engine build - Few Questions

[Zed Head]

Woops.  Didn't know "Kameari" referred to the whole list.  The stock gear is adjustable.  Also didn't realize there were so many Kameari parts.  There's even a mustache bar.  I seem to recall people having problems in the past with the Kameari ignition system because it has no instructions.  Should be fun to get running once assembled.

Motorsport is behind the times with their search results but if you put the right word in a lot of stuff comes up.

http://www.thezstore.com

[Jason240z]

3 hours ago, Patcon said:

He evidently has one of those if I read the original list correctly

Exactly. 

[Jason240z]

6 hours ago, Diseazd said:

Pretty much nailed it Zed Head. I prefer the P90/P79 head shaved down and shimmed up to get 10 to 1 CR minimum. A high duration, high lift cam (I run 17 degrees static advance on all 5) with performance valve springs to handle the rpm. Swirl valves help the engine breathe....I run SU’s and love their simplicity (can’t seem to step up to trips)....they work amazingly well for all my engines, through full rpm (up to 7500) with no sign of not being able to adequately feed them. The only thing I think would really bump them all up is CR. If I could run 13 to 14 to 1 CR on pump gas, I would. All 3 of the different engine set ups that I’ve built are a blast. Like kids, it would be hard to say which one I love most!

I like those builds, I think this is closer to what rebello call their 2.7 purist build 

[Jason240z]

So after lots of measuring,checking and thinking, I've decided I'll need new pistons.

So custom pistons (+2mm)

140mm forged fj20 type rods

260/280 crank.

I'll then have a perfect 2.7, perfect squish, great rod/stroke ratio and importantly a serviceable original block.

[gundee]

1 hour ago, Jason240z said:

I'll then have a perfect 2.7, perfect squish, great rod/stroke ratio and importantly a serviceable original block.

What exactly is "squish" referring to? 

[siteunseen]

I've always heard "quench" but now I see there is a 'squish" also.

"The quench area is the tight area between the flat portion of the piston and the flat portion of the combustion chamber in a typical wedge-style chamber. ... With a flat-top piston, this squish area can be very tight. This is also the tightest clearance between the piston and the cylinder head.

http://www.superchevy.com/how-to/engines-drivetrain/94138-piston-head-clearance-guide/

 

Edited September 4, 2018 by siteunseen

[gundee]

That Superchevy page is good reading. I plugged my new L24  proposed.engine build into that S30 Engine Modeller and got a no-go on the squish.

I have the over size pistons and the block bored out, but not assembled yet. I will have to put that issue in another thread. Not here

Edited September 4, 2018 by Lumens

[Zed Head]

It's one of those engine building concepts, to create the best combustion process, I believe.  The "squish" is supposed to propel the gases in the squish area out across the combustion chamber for more complete combustion.  There is also a cooling effect on the top of the piston that some people propose happens as it gets so close to the head.  What's not really clear though is how the rest of the chamber design comes in to play.  Valve and port orientation and the way the gases flow in to the cylinder,  spark plug location, things like that, all come in to play, I think.  

The OP has put together a set of "perfect" concepts, but it's unknown how all of the perfection will work together.  There's a good thread on Hybridz by BRAAP and Ron Tyler, where they took all of the "known" ideal concepts, including quench and porting and a new intake manifold design to build an engine.  When they dyon'ed it, they couldn't get much power out of it without major detonation problems.  They used Megasquirt and knew how to tune but the parts just wouldn't work together.

[Jason240z]

its not dissimilar to the rebello purist,so it'll work, custom pistons allow me to make it work as a whole package.

[Patcon]

7 minutes ago, Zed Head said:

It's one of those engine building concepts, to create the best combustion process, I believe.  The "squish" is supposed to propel the gases in the squish area out across the combustion chamber for more complete combustion.  There is also a cooling effect on the top of the piston that some people propose happens as it gets so close to the head.  What's not really clear though is how the rest of the chamber design comes in to play.  Valve and port orientation and the way the gases flow in to the cylinder,  spark plug location, things like that, all come in to play, I think.  

The OP has put together a set of "perfect" concepts, but it's unknown how all of the perfection will work together.  There's a good thread on Hybridz by BRAAP and Ron Tyler, where they took all of the "known" ideal concepts, including quench and porting and a new intake manifold design to build an engine.  When they dyon'ed it, they couldn't get much power out of it without major detonation problems.  They used Megasquirt and knew how to tune but the parts just wouldn't work together.

Zed, do you have a link to that thread?

[Zed Head]

Sorry, I think I blended two threads together in my head, or assumed that the head they built was designed with "squish".  Actually, I can't be sure, the details aren't in the thread.  Here's the thread I was thinking of and another I found when I was looking.  Sounds like he used an open chamber N42 head.

http://forums.hybridz.org/topic/51825-scratchbuilt-l6-efi-intake-manifold/

Here's some squish stuff.  I've found a lot of inconsistency in what people write abut quench/squish.  For example, you'll find people taking about how the piston has to be within a certain distance to the head or you'll actually create a detonation hot spot.  But then when you do the math on their engines you find that it doesn't fit, they have no quench.

http://forums.hybridz.org/topic/63444-l6-squish-discussion-the-battle-against-detonation/

BRAAP has a post out there somewhere about getting the piston so close to the head's quench pad that the piston number transferred to the head, in the carbon residue.  Sounds neat but not clear if an actual benefit was measured.  That's the basic problem.  Showing that it works.

 

[Zed Head]

Here's something beyond quench...  (For thought only.  It's voodoo.).

https://www.google.com/search?client=opera&q=Somender+Singh+Grooves&sourceid=opera&ie=UTF-8&oe=UTF-8

http://www.herningg.com/projects/groovyheads.html

https://somender-singh.com/index.html

Edited September 5, 2018 by Zed Head