620 Land Speed Record

[Profile]

Your allowed to run a cast flywheel? Though no rule body (SCTA) would allow that. At 8000+ rpm that is asking for one fun experience. Don't cut corners where it really counts.

[distributorguy]

Cast steel not iron yes.  This is a medium strength high carbon steel alloy flywheel.  After spending 2 hours carving on it I realize how well these are cast.  Better than most if not all aftermarket options.  Cutting corners?  Are you kidding me?  Aluminum flywheels are the ones that are banned.  I'll have a custom SFI approved ballistic flywheel blanket, its forward of the passenger compartment, and the floor over the transmission will be both guarded with cage and steel plate.  I may cut even more off of it if we can't run a starter with our arrangement (ring gear and everything around it).  Besides noone of the aftermarket steel flywheels are heavy enough for land speed racing (momentum).  

[G-Duax]

I had taken 10 lbs off one of those, and never had any issues with it.

The OS Giken multi-plate set up are very heavy, and not just because of the clutch pieces,

and they are fairly easy to find, since the L6, and RB interchange with your L20B.

 

+1 on the aluminum crap should be banned. Never seen a used one that wasn't on the verge of falling apart.

[distributorguy]

I'm playing a balancing act with weight.  I have a 720 L20b flywheel that weighs one metric shit ton.  I need to find a happy medium between dampening high rpm harmonics and good acceleration.  16 lb flywheels have always been my street solution, but this one is sitting at 21.  The clutch will likely be Chevy or BMW.  The transmission adapter plate will accommodate both transmission bolt patterns.  

[fastdadd]

I'm not sure who has the file or actually cut them out, but a few people received a laser cut metal rat and wrenches for different aspects of the Canby raffle truck last year.

ask [redeye....he would probably do it 

[Jester]

Shaved flywheel minus 7 1/2 lbs.  Still heavy, but better.  

 

 

If you decide you want another half pound out, use a stock Z24 flywheel. 

And I really like your timing cover. 

[datzenmike]

 

The z car 225mm clutch wheels were cast 21pounds stock. Most L20B 200mm and 225mmand under are 31 pounds. The Z24 uses a 240mm clutch and the wheel is (I think) 21 pounds because of the torky displacement and the already heavier 240mm pressure plate assy.

[distributorguy]

Thanks for the pic Mike.  It look slighter, but has significant mass around the perimeter which is undesirable.  That means I can definitely remove more weight from mine and not risk a fracture.  I can't read the casting.  Is it still an A87 alloy?

[datzenmike]

Actually the one shown is a U60 so from an L20B. The Z car one is a P(something) I think they are all cast the same way

[datzenmike]

Little late but, from DATSPORT Australia.....

 

 

 

Specifications for machining L series flywheels. This spec can be adapted to 4 & 6 cyl fly wheels.It is suggested that the portion contacted by the disc be increased to min 13mm for street use.

[Jester]

That is good info, late or not. 

[distributorguy]

I just used the same rule of thumb I use on all flywheels, which is in that 13mm range, although my goal here as I said before wasn't to make the lightest flywheel.  

[distributorguy]

Someone else had asked about windage trays.  Here's what I've started, although I think I'm going to make it bolt into the oil pan.  If I don't, I'll have to make the rest of the pan rail, so the oil pan sits level.  No big deal either way, but sometimes simpler is better.  The oil pan will take days to fabricate, as the straps on the main caps interfere with pan fit.  I could mill them away, but I'd rather deal with the pan and leave well enough alone.  

[skyshadow]

Definitely subscribing to this! Good build! 

[G-Duax]

I like the main cap girdles, especially for #3 & #5, which have the 8mm hole in them.

I may do those 2 on my engine, just maybe a little less thickness.

[distributorguy]

If you strap the caps, 2,3,& 4 are the most important.  They're the ones that will move around under stress.  #5 has the whole rear of the block to keep it stable.  Plus you have to machine your caps flat, then line bore/hone because the bores WILL distort after milling.  Build the height to whatever studs you source.  The width should match the caps, or at least be wide enough to not cause stress points at the stud holes.  

[Jester]

The KA had a full girdle under the pan. Perhaps it would provide a start with more room? 

[distributorguy]

Not legal in the Production class, as far as I know, plus we decided to stay in the least competitive 2 liter class.  Not a bad idea for our "backup" motor however, but the main straps are probably more effective for what we are trying to accomplish, in combination with block filler.  

[distributorguy]

I can't remember which cage pics I posted.  This once shows the clearance I had to add for the front wheels, with a large area sectioned out above and behind the front tires.   [/url]">http://http://s1148.photobucket.com/user/distributorguy/media/cage_zpsueu2iisz.jpg.html'>

[Jester]

There is a lot in that pic to like. I wouldn't know where to start.  :thumbup:

[skyshadow]

I like how the tire labeling is in gold/yellow. That's pretty rad.

[distributorguy]

Flow benching the head today.  Manley valves are fitted.  Ported pretty severely but the job is not completed.  Got up to 220 cfm on the intake so far, definitely room for improvement.  That puts us in the 225 hp range if everything else plays along.  25 more to find somewhere.  

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[Jester]

Starting to look like an FIA head.  B)

[datzenmike]

[distributorguy]

I have a small chamber 1980 head with round exhaust ports that I think I can get closer to the FIA.  These are my training wheels.   :thumbup:

Besides, the flow numbers are pretty good.  Intake to exhaust ratios are very, very good too.  This is the A87 small chamber head that is "no good for performance" according to many.