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620 Land Speed Record


distributorguy

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I've even moly coated bearing inserts, cam tower journals, timing sprockets, valve guide bores, and the complete internals of oil pumps.

Nice thing about pistons, being moly coated, once you wear through the coating, just re-coat :-)

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When I did my bearing inserts, they were too tight, and I had to hone them to get my clearances back.

Used my dial type cylinder hone, with 600 wet or dry paper around it.

Pistons, valve guides, cam journals, sprockets I don't worry about, since the coating thickness isn't much, and I'm dealing with used parts most of the time anyway. 

 

Oh, and don't abrasive blast the bearing inserts, the grit will imbed into the soft bearing material.... 

 

Chains can be done, but they need to be pre-run to take set, then degreased very well, soaked in the moly, baked, and then broken free, as it glues the links together. But chain life goes way up on something like a 18,000 rpm kart engine.

Too much work for an L-series.

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Speed Week is August 12-18th this year.  Anyone on this forum is more than welcome to come visit us in the pits while we're playing with the truck.  Fingers crossed that the race happens this year.  

 

They shipped out a huge box of materials for me to try including the thermal dispersant to coat the radiator, all the dry lubricants to coat rocker arms, the cam, oil pump internals, etc...  

 

We're having a difficult time finding room for ballast in the truck.  Experimenting last night, we found we need about 600 lbs at the front of the box to get a 25/25/25/25 balance with a variance from high to low of 11 lbs.  All ballast is supposed to be forward of the rear axle for safety.  Maybe we can squeeze some steel solids on top of the frame, under the box.  Still a high center of gravity but lower than in the box floor.  We need to get this thing back up on the hoist, but my hoist is not in the heated shop.  Ughhhh 

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We're trying to offset weight to the rear.  We're at 53/47 F/R without that 600 lbs ballast currently.  The ballast needs to be bolted securely to the frame.  Even if we put steel sheet on the bed floor, it needs to be bolted through the frame with solid stand-offs.  That's where this gets simply time consuming coming up with a safe option that the tech inspectors will like at first glance.  That's the real key.  Safety first, balance second.  

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Steel is $.50 a lb.  Lead is $1.25 pound or more, although I can order a 500 lb pallet for $700 plus truck freight, plus lift gate fee (another $400).  Shot is $1000 for 600 lbs.  Or get 600 lbs of steel locally for $300, and I can use it later for another project when we're done racing. 

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A special thank you to Tech Line Coatings for providing all these great chemicals to treat almost every internal component of our engine, and many external components!  They will go to good use, and we will abuse them as hard as we can!

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You will have the moly coat stuff for a long time if you keep it sealed.

I've had mine for probably 5 years, and I doubt the level has went down an inch.

I did put a couple of 1/2" steel balls in mine to mix the stuff up by shaking, as the moly tends to settle out.

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Got a little more work done over the last couple days.  Sprayed some of the Tech Line Coatings on the head, valves, intake manifolds, and got a solid start building a box cover.  The cover has to be flush with the rails,  no exceptions.   

 

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Since Tech Line Coatings sponsored us, I disassembled the engine, cleaned off the pistons, blasted them, and coated the tops with ceramic CBX, the skirts with a thermal barrier lubricant, and the interior with a thermal dispersant that sheds oil quickly.  

 

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[/url]">http://http://s1148.photobucket.com/user/distributorguy/media/Datsun%20project/8C215581-1150-4D4F-97CE-D3250B16E208_zpsajqix0fw.jpg.html'>8C215581-1150-4D4F-97CE-D3250B16E208_zps

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Already done, although there was very, very little.   And the CBX is all polished with an ultra-fine industrial steel wool I got from a friend who owns a Teflon applicating shop. I wish I could find out where he buys it.  It doesn't "shed" like normal steel wool.  The texture is more of a loose long-stranded braid.  

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:thumbup:

I'll be tearing down the motor every year after Bonneville, so at that point I can re-coat if needed or replace or ???

My goal is simply to reduce friction enough to make a difference.  Between a proper oil choice, coatings, bore finish, ring sizes, bearing widths, rotating mass, it all matters.  

 

The build rate of the skirt coating is ultra-thin.  I think about 20 layers would equal a wet coat of the ceramic on the piston top.  I wouldn't doubt if it was worn through by the time we finish racing this year.  But the point is that its sacrificial, instead of sacrificing metal.  With the exception of the ring lands and the wrist pin bore, the entire piston has beneficial coatings.  

 

I also used the "special" additives for breaking in the rings and the dry film lube on the bore.  They probably should have been used separately, but WTH.  

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I was wondering how much pressure loss there would be if I switched over to a gapless top ring and eliminated the 2nd ring, still run a low tension oil ring.  In terms of surface area of drag, it would be reduced by half.  This is something I'd wait to try until after I can at least get a scuff on the cylinder walls. 

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As far as pressure loss with gapless rings,

when doing something on my Toyota, and I need to turn the crank for some reason. it's a real pain in the a$$ due to the gapless rings.

Goes like this:

Breaker bar & socket on crank snout, turn crank, release pressure, crank turns back to where it was.

Turn crank again, hold in position for 60 seconds, release pressure, again crank turns back.....

Go fetch #1 son, have him turn crank & hold the damn thing while I plug the distributor, of check valve clearance, or what ever.

 

But they need to go in the engine before firing it, so the hone roughness on the cylinder seats them in properly.

Putting them on a already run bore won't give you that result.

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My past experience with Total Seal was total crap.  To be honest, they never seated, using good break-in oil, a fresh hone done properly, and a legitimate break-in.  Never saw better than 7% leakage past the rings.  I've been using JE's supplied Hellfire rings with their pistons ever since, with good luck.  They seem to not only seal better, but they don't pump oil and they hold up to extreme boost.  They also work on simple 9:1 street motors.  Other guys tell me to use a gapless 2nd ring and you don't get the oil pumping.  Makes me think you could skip the 1st ring...????

 

I think some of the new ring break-in additives could do a better job at breaking in the Total Seal rings, but I'm not brave enough to get burned a 2nd time.  Yet.  

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