Author Topic: 69 302 on pump gas?  (Read 4192 times)

X33RS

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Re: 69 302 on pump gas?
« Reply #45 on: January 18, 2017, 10:53:01 PM »
An ounce per tank won't do what we are trying to accomplish.  Doesn't hurt but to be more affective a larger dose is needed.  A handful of us experimented, a lot of trial an error, probably a little more than 10 years ago looking for a cheap alternative.  What was found is that an ounce per 5 gallons was about perfect.  Less didn't make a change and more simply caused a smoke condition.   Excellent lubrication properties and cleaning ability with the stronger mix ratio.   But I only brought this up because the discussion turned to the addition of ethanol in the fuel and corrosion concerns, I don't mean to sound like I'm trying to sell this backyard remedy to anyone.  With the horror stories I've read about corrosive ethanol, I've always felt the 2 cycle combats the ethanol corrosion to some degree just based off the dozen cars I use it in and having no fuel related corrosion issues to speak of.   Just a cheap and effective alternative to add to the crap fuel we have rather than buying expensive fixes in a bottle off the shelves. 

Bigblockbird

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Re: 69 302 on pump gas?
« Reply #46 on: January 19, 2017, 02:34:56 AM »
Oh.  Well I guess I'm not gaining anything at .030.  ;D

I remember using the steel shim gaskets back in the day.  I used to paint them with aluminum paint on both sides before assembly.

I think I like the multi-layer type gaskets better for long term seal.  Any opinions on that?

I build and run Race cars. My current Big block Chevy in my 67 Nova Carbon Fiber/ Fiberglass composite  bodied Tube Chassis drag car is an all Dart 582 inch engine with a net compression of 15.25-1, I run on Methanol with 5% nitro-Parafins in it called M-5 from VP.
I EXCLUSIVELY use Multi Layer Steel Gaskets from Cometic and they never fail, they crush consistently and can easily handle the cylinder pressures of my high compression engine.
I will never use anything other than MLS unless trying to stay true to an all original scenario, even then, who's gonna' see your head gaskets.

cook_dw

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Re: 69 302 on pump gas?
« Reply #47 on: January 19, 2017, 02:56:40 AM »
I EXCLUSIVELY use Multi Layer Steel Gaskets from Cometic and they never fail, they crush consistently and can easily handle the cylinder pressures of my high compression engine.
I will never use anything other than MLS unless trying to stay true to an all original scenario, even then, who's gonna' see your head gaskets.

Darrell Cook

Contact me if you have a 68 L78/L89 Camaro to add it to my database.

deadmetalprez1952

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Re: 69 302 on pump gas?
« Reply #48 on: January 19, 2017, 03:00:56 AM »
I would use MLS gaskets if they were thin enough but that would lower compression too much. I will be using .015 steel shim gaskets. I thought about milling the heads to use thicker gaskets but I don't want to ruin the quench...

X33RS

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Re: 69 302 on pump gas?
« Reply #49 on: January 19, 2017, 04:05:43 PM »
They make MLS gaskets as thin as .027" for SBC with a 4.060" bore.   I think that's about as thin as they get.  They offer a large variety of thickness to taylor quench and compression.   It's a great gasket, I've used them before on LS builds here, but I considered them overkill for my little 302 build when I could use a standard gasket that gave us exactly the quench we were looking for at half the cost, thanks to putting the pistons close to zero deck.  Bischoff recently used MLS gaskets on my fathers 571 pump gas street engine though.  Only 10.84:1 compression on that engine but Tony doesn't mess around.

I'm not sure exactly what you are working with Deadmetal, but if it's a factory deck height block with factory internals you can bet the piston is going to be .020"-.025" in the hole minimum.  Even with the steel shim GM head gasket at .015" these engines when they are virgin don't have the 11:1 compression they advertise (mine didn't)  They usually fall a tad short.  So in that case I agree, I wouldn't want a thicker head gasket on there.  It lowers the compression more, but also hurts quench and can possibly make the engine more susceptible to detonation if it's tuned on the edge.
   The old thinking was putting thick head gaskets on an engine with high compression was the way to make it tolerable.  But smart engine builders quickly found out that was a bad idea.  Especially when dealing with dinosaur cylinder heads with poor combustion chamber design.

GreenNV

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Re: 69 302 on pump gas?
« Reply #50 on: January 28, 2017, 02:41:00 AM »
Looking forward to a 302 build here in the next few weeks and will have to see how this one reacts to pump gas?

The block will be freshly machined before reinstalling the 302 crank with a new set of 4340 competition series I-beam rods and a new set of forged slugs. This one's getting a Lunati .582" @ 254/262 solid roller cam so it should run like a nasty little thing. The best part is I'll then be waiting to take stock in a new set of Trick Flow 186 aluminum heads. They are a few months from being released and I'm pretty stoked to be in line for a set of these new 185cc aluminum castings. Heads flow 254/207 @ .600" and they accommodate a 1.500" spring required for newer solid roller cams. The engine will then be topped with an Edelbrock Tarantula intake and an AED 750 mechanical carb. I'll post a video of it running before I install it into the green car. Should make a fun little motor to rip around in.
1968 Grotto Blue Rallysport  - GM Canada Docs
1969 Rally Green Z/28 - GM Canada Docs
1955 Chevrolet