High Compression Head Gasket

[OneTimeUser]

First of all, I looked around and could not find the subject discussed. Surprising.

I'm thinking of trying a 10 thousands head gasket to up compression a bit on a stage 1 HEMI 212 as an alternative to getting the head milled. I understand stock head gaskets are 45 thousands.

Does anyone have experience with these? There is some stuff on Utube, but I'm not sure they know what they are talking about or understand what the are doing.

My piston, rod, crankshaft, and camshaft are stock. Governor is removed, it has a 24mm Nibbi, and a garden-variety Amazon exhaust header.

Thanks in advance.

 

[Hellion]

Search "thin head gasket". I think folks are more interested in milling the head, using a flat top piston AND in conjunction with a thin head gasket (usually copper) to raise compression.

 

[Whitetrashrocker]

From my little experience. Your going from a .045 to a .010 head gasket. Basically the same as milling off .035 and using easy to get stock gaskets.

Ive taken .040 off just about every engine and haven't run into PtV issues. This is with stock parts.

Once you start mix and matching internals you need to make absolutely sure you have the clearance. Using clay and assembling the part about 1500 times.

If you want a bit of power gain. Id slap that head gasket on and see if your butt dyno can feel it or not.

 

[Edwin Spangler]

Are you still using the stock flywheel?

 

[OneTimeUser]

Thanks all for the help. I think I'm gonna give it a try. I still have the stock flywheel. Most of the billet flywheels for the HEMI cost close to whole a new engine and I don't even know how many hours this one has on it.

Plus, since this is a cart and not a mini bike my privates (AKA the home entertainment center) are not in proximity to the engine I thought I'd just wait and see if these stock flywheels actually grenade. I've read many conflicting reports.

I'm still messing with this little Fox Hornet cart until (at least) I get my Murray Kilowatt off of stands and on the ground. I'm getting close. I probably will end up keeping them both. The little Fox is tons of fun.

 

[Edwin Spangler]

Plus, since this is a cart and not a mini bike my privates (AKA the home entertainment center) are not in proximity to the engine I thought I'd just wait and see if these stock flywheels actually grenade. I've read many conflicting reports.

The risk is always there. Magnet flying off.

 

[OneTimeUser]

Edwin,

We will see. If it frags I'll give a full report and post pictures

 

[Sparkwizard]

I run .010 steel shim head gaskets on Predators all over the farm. High ratio rockers, GOVERNOR is installed with stiffer springs, and Tillotson blueprinted stock, adjustable carburetors. I do not need more power or speed than these engines produce when set up like this.

 

[Edwin Spangler]

Edwin,

We will see. If it frags I'll give a full report and post pictures

I do this just to feel a little safer.

 

[OneTimeUser]

Edwin,

Great idea. I remember the hot rodders placing "scatter" shields on their transmissions for the same reason. If I recall, they were more or less like a flack jacket.

 

[Master Hack]

Leave a pair of wrenches on the frame?
What is this? spares? or does it have a function? just curious. Like to learn little tricks like that from the old pros.
I may be old but I have never been confused with a pro anything!

 

[Master Hack]

Back to the head gasket question:
I have used those on different engines with good luck. Just be sure the surfaces are clean and flat. You can easily lap your head, actually the engine's, on a piece of glass and some wet (or dry) 180 sand paper.

 

[Whitetrashrocker]

I built mine with a different thought process.
I port and polish the head. Deck .040 or so off. I run stock springs and no governor. Valve float is the rev limiter. Put in a few degrees more advance timing. I haven't had a magnet fly off yet.
I like the lobe separation on the stock cam because it keeps the torque down low and idles well.

With the added compression and early spark i run 100LL gas.
The slower burn makes a longer power cycle. It smells good too!

A slide carb and open exhaust.

An engine is just an air pump.
Making it efficient is the key.

 

[Hellion]

Most of the billet flywheels for the HEMI cost close to whole a new engine…

No need. Plenty of rated flywheels for that engine that aren’t billet (or at ARC billet prices), plus that $26 one off Scamazon rated for 10K

PVL Flywheel Predator 212 Hemi

OMB Warehouse - Go Kart Parts and Mini Bike Parts. OEM and Aftermarket supplier of Outdoor Power Equipment Parts, Arborist and Landscape Supplies.

www.ombwarehouse.com

SK Rev Wheel V2 Gold Billet Flywheel – Predator 212/224 Hemi | Lightweight Racing Flywheel

www.eccarburetors.com

Cast Aluminum Flywheel – Tillotson 212R, Wildcat 240 & Honda/Clone Engines

www.eccarburetors.com

These are just random options, I did not organize according to Hemi or non-Hemi.

 

[OneTimeUser]

Thanks gents. Plenty to ponder.

 

[OneTimeUser]

Master Hack,

This is a little off subject, but, I'd like to see a picture of the machine you showed a close up picture of. I can tell it's custom made and I'm just curious. Thank you.

 

[Hellion]

GOVERNOR is installed with stiffer springs

This is next level, transcendental. More tension on the governor spring yields a higher max RPM. The tech manual manner of doing it usually involves bending (how primitive!) the governor lever arm to exert more tension on the spring, but I like this better. Maybe you can write a short thread on it?

The governor is in fact not a rev limiter but a rev maintainer.

 

[Master Hack]

Master Hack,

This is a little off subject, but, I'd like to see a picture of the machine you showed a close up picture of. I can tell it's custom made and I'm just curious. Thank you.

If yer referring to the above pic, that is not mine.
My junk is here:

Project Stoopid!

Here's tube. Its just hard to flare the ends.

www.diygokarts.com

 

[Edwin Spangler]

Leave a pair of wrenches on the frame?
What is this? spares? or does it have a function? just curious. Like to learn little tricks like that from the old pros.
I may be old but I have never been confused with a pro anything!View attachment 161216

Lol funny guy... Just wait till you see my nut couplers.

Just 3 nuts being used as a spacer. I have a LOT of random misc. hardware.

 

[Master Hack]

Random nuts? Sounds like DIYGK member list!