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620 Land Speed Record


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#241 Stoffregen Motorsports

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Posted 11 January 2017 - 10:28 AM

HKS used to make the composite steel head gaskets. Don't know if they still do. There is another company that makes them, but I can't think of their name right now. The cool thing about them is that they are reusable and rebuildable, and even adjustable by adding or removing shims to raise or lower the compression ratio.

 

If you can't find one, I would just o-ring the block and bring to the track a few OEM Nissan gaskets. Even the GT motors still use OEM gaskets.

 

Hopefully you're not going to use head studs though as they make head R&R a pain in the ass.



#242 distributorguy

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Posted 11 January 2017 - 12:43 PM

I am using ARP head studs and a Nismo gasket.  ARP nuts are eaier than stock bolts, and we need more strength.  Over 15:1 compression, naturally aspirated.  Its not likely to see even 50 miles between engine rebuilds.  It'll be ok.  Once the motor is certified (if we back-up a record run), and if we fail the whistle test, then we pull the head.  No big deal.  4 hood pins, so that's not in the way, big pop-up tent to work under on the salt.  

 

Guys, when you offer advice, keep in mind this is Bonneville.  Relaxed pace, almost never full throttle to modulate tire slippage, very high compression, never touch the brakes, light load top speed racing with soft shifts.  Durability is only for RPM, not load until peak speed, then the load is wind not traction.  Its boat racing with wheels and salt and even less traction.  Nothing about it is similar to track racing.  



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Posted 11 January 2017 - 02:32 PM

It's drag racing on a 5 mile dirt/salt track.



#244 Stoffregen Motorsports

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Posted 12 January 2017 - 09:20 AM

I guess using studs is the price you pay for such a high CR.

 

I freakin hate em.



#245 distributorguy

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Posted 12 January 2017 - 11:48 AM

I've installed SO many sets...  I like 'em.  Once you figure out how to NOT drop and lose washers and nuts it just becomes a way of life.  

 

Drag racing WOULD be like Bonneville if you needed a 3-4 TON car weight to have enough traction to achieve 200 mph.  That weight also has to be perfectly balanced to avoid spinning out.  Grease the track, then compare drag racing to racing on salt.   :thumbup:



#246 distributorguy

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Posted Yesterday, 02:13 PM

So I think we have a solid plan for the fuel system.  Carter "black" fuel pump - 90 GPH, 7 psi.  Aeromotive ultra-low pressure fuel regulator with 15 psi gauge, 6AN and 3/8" OD stainless lines throughout.  

100 micron filter before the pump, tank modified with a 3/8" OD outlet for fuel supply.  Both vents tied together and Teed into a roll-over valve so the tank can't leak if we crash.  The pump is wired with a relay, 30A fuse, and impact/rollover switch (From a Ford Taurus).  

 

The carbs will be plumbed later with another 30 micron filter either before the regulator or two filters after the regulator to decrease the chance of debris restricting fuel flow.  Each carb gets its own line from the regulator.   Fuel starvation would become insanely expensive, so we're going to avoid that at all costs!!!

 

I've looked at doing a fuel cell, but most are just tanks anyway, with no real protection from a crash.  The factory tank is legal, and in a very safe place, plus it helps balance the driver's weight.  When I have a spare $1000 and no go-fast goodies to spend it on, I'll buy a Fuel Safe.   I've got $400 into this system, using a LOT of parts I already had around.  It could easily reach $2k if I bought all new goodies.  I still may have to buy a higher pressure pump to get the fuel pressure consistent.  We'll see how this plays out with the SUs for now.  The Webers get installed in about 3 months.  



#247 Stoffregen Motorsports

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Posted Today, 12:26 AM

Are the fuel inlet nipples on the SU's removable?  Some of them are not removable, while the threaded fittings vary between applications. Some are BSPT, some are straight threads.

 

Weber DCOE's use a 12mm x 1.5 thread pitch and Mikuni/Solex uses a 12mm x 1.25.

 

It would be nice to plumb -6 all the way to the carbs with fittings instead of hose clamps.



#248 distributorguy

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Posted Today, 05:51 AM

My Webers are 10 x 1.5.  Oddly small, but adequate.  I ordered -6 fittings for them, so they'll be well fed! The SUs don't matter.  They're for low rpm use, only to get the truck aligned, balanced, and work out a few bugs.  Plus they are on the spare engine.  The race motor goes in later with the Weber setup.  Their nipples are press-fit.  Only the older ones have banjo fittings.