World Formula proposal

Bruce Jackson · Posted: Wed Nov 11, 2009 10:53 pm Post subject: World Formula proposal

In an effort to reduce the cost of building a competitive Briggs World Formula motor, I propose the following amendments to the current rules in regards to the deck/piston clearance specifications.

The current rules allow the machining of the deck of the cylinder, or piston crown to achieve a maximum pop out of .025”. My proposal is to allow the use of a head gasket whose thickness will achieve the same result.

The current rules require the use of a factory head gasket that has a minimum thickness of .042”. That equates to a clearance of .017” from the crown of the piston to the top of the gasket surface, considering the pop out has been set at the maximum of .025”. Currently, the only way to achieve this is to have the block or piston crown machined, which can be a significant expense.
As an alternative, this same tolerance can be achieved by allowing the use of an alternate thickness in head gaskets, to compensate for the variations in pop out, which is common with the “out of the box” motors.
As an added benefit, this would also simplify the tech procedure as the pop out can now be checked with a straight edge and feeler gauge between the piston crown and deck, with the head gasket in place.

This type of adjustment is commonly done with the 2-stroke motors to adjust port timing and combustion chamber volume, and has proven to be a cost effective means of improving performance.
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Bruce Jackson

Dean Graves · Posted: Thu Nov 12, 2009 11:08 am Post subject:

Proposal for who or which racing sanction?

Have to square up the cylinder anyway, might as well deck the block too. Once the head has been shaved it's done till you toss the head. The W/F is the cheapest blue print out there and makes it easy for the tech. barn.

Bruce Jackson · Posted: Thu Nov 12, 2009 11:59 am Post subject:

I suspect that the IKF and WKA rules are the same for the most part. My point is to have an option to spend $15.00 to get the same result you can achieve by machining the cylinder; I'm just talking about adjusting the pop out, not an entire remachining of the block and head. Don't worry, there will always be racers that will pay you the extra $500.00 to gain that 1 additional horsepower from a complete blueprint. Razz

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Bruce Jackson

Chris Brunnemer · Posted: Fri Nov 13, 2009 10:44 pm Post subject:

to me 1 hp is worth a lot more than 500 dollars. 1 hp out of 15 is about a 6% gain. that is a lot of extra power over the others.

Bruce Jackson · Posted: Fri Nov 13, 2009 11:10 pm Post subject:

OK, I give up; it was a dumb idea that isn't worth considering. Who in their right mind would want to potentially improve the performance of their motor at a reduced cost when the current rules disallow it?
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Bruce Jackson

Bob Vehring · Posted: Sat Nov 14, 2009 12:15 am Post subject:

The problem with your plan is pop up from the factory can be all over the place. each engine or each production run can be different. One size gasket is not going to be the answer for each engine.
As said, decking the block is a small part of blueprinting
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Bob Vehring
www.4cyclecentral.com

Bruce Jackson · Posted: Sat Nov 14, 2009 9:36 am Post subject:

That is precisely my point; the pop out is all over the map. I noticed that American Powersports, and I'm sure there are others, offers copper head gaskets that range in thickness from .020 .050 inches, which would afford some means of adjustment. Currently the IKF rules require the use of the B&S head gasket, which comes in one thickness only, therefore the only option is to machine the deck or piston crown to obtain the maximum allowed pop out.
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Bruce Jackson

John Matthews · Posted: Fri Dec 04, 2009 2:51 pm Post subject:

What you say makes sense, and it might reduce costs for casual racers who really don't want the expense of blueprinting their engines.

But, this really isn't the right place for rule change proposals. Check with your region administrator to find out the process for bringing this up.

Alternatively, since the racers this would benefit are probably just running at the club level check with your track rules committee. They could use the "local option" clause in the rulebook to allow it at your track if your fellow racers agreed.

Good luck,
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John Matthews
Heartbeat Power, LLC.

Bruce Jackson · Posted: Fri Dec 04, 2009 11:44 pm Post subject:

Thanks for acknowleging my suggestion John; it semed to me to be a ressonnable alternative to the additional expense currently required to improve the engines performance within the rules.
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Bruce Jackson

Chris Koch · Posted: Fri Dec 25, 2009 12:43 pm Post subject:

What kind of head gasket do you use if the piston is only .001" out of the block? -.024"? I have not seen this extreme of example but there are some that don't come out too far. If all were too high a gasket would be a great answer.
Just a thought>

Chris

charles hunter · Posted: Sat Dec 26, 2009 1:52 pm Post subject:

My answer to this absurd craziness karting has fallen into is allow NO Blueprinting of any motor whatsoever. If your not going fast enough, BUY A DIFFERENT MOTOR. Go back to stock or modified classes. Modified meaning blue printed and up. Idea

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Bruce Jackson · Posted: Sun Dec 27, 2009 5:42 pm Post subject:

Dean Graves · Posted: Sun Dec 27, 2009 8:25 pm Post subject:

I must be confused, 0.000pop out is still 0.000 pop out with any gasket. Pop out used to be measured with out gasket and in relation of the deck of block/ cylindr edge.

Bruce Jackson · Posted: Mon Dec 28, 2009 8:13 am Post subject:

I guess it is a bit confusing, as it's not actually popout when you measure with the gasket in place. It's the distance from the top of the piston to the cyliner head surface. With the maximum allowed popout of .025", measured from the cylinder deck surface, and the stock head gasket in place, which is .042" min., you have a clearance of .017" from the piston crown to the top of the gasket. If I have .000" of pop out, I have.042 " of clearance with the stock gasket. Now if I used a head gasket that is .020" thick, I have .020 " of clearance, which would be the same clearance between the piston and head surface as having .022" of popout while using the stock gasket. Does that all make sense now, or have I totally confused you?
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Bruce Jackson

michael schorn · Posted: Mon Dec 28, 2009 10:55 am Post subject:

Bruce
I see your point but it would be somewhat difficult to measure since in my opinion the head gasket would have to be compressed in order to get a true measurement of pop out with head gasket in place.

Also it would make for teching somewhat difficult since most of the composite head gaskets tend to come apart when removing. The fire ring gasket seems to stay together okay but the old style stock gasket does come apart at times and reinstalling to measure may give an erroneous reading.
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OK everyone It's my opinion only, no one elses, and does not reflect any organization or office that I belong to or hold. Thank you for your support.
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