October Fastrack, flywheel weight passed!

[Dave Hopple]

http://www.scca.org/news/tech/fastra...0-fastrack.pdf

Lot's of interesting things in this months issue, good news (see below) and some not so good news (I'll let you guys figure it out on your own) -Dave


FORMULA FORD
Item 4. Modify the wording of FCS
Section 17.1.6.D.2.1 effective 10/1/03.
Weight with ring gear:
15.5 lbs. Minimum for the original and uprated engine.The flywheel may be machined provided the machining to reduce weight to the above minimum weight retains the standard profile.
An alternate flywheel from JAE part # JAE 1600 is also allowed to the above weight of 15.5 lbs.
PASSED

Item 5. Modify the wording of the FSC
section 17.1.6.D.2.e. effective 10/1/03.
3. Pocketing of the piston valve reliefs is allowed up to a maximum of .050" to obtain the minimum combustion chamber volume.
PASSED

TECH BULLETIN
DATE: July 22, 2003
NUMBER: TB 03-10
FROM: Competition Board
TO: Competitors, Stewards, and Scrutineers
SUBJECT: Errors, and Omissions,
Competition Adjustments, Clarifications,
and Classifications.


Formula
Formula Ford
1. Section D.2.c, p.50, add to the end of the paragraph: "The following headgaskets are allowed: Ford Part # 931M6051AA, Payen Part # AH-750, Felpro Part#8360PT-1".

[size="1"][ August 26, 2003, 11:48 AM: Message edited by: Dave Hopple ][/size]

[James Hakewill]

My 2001 GCR says:

Original engine 17.4lbs minimum
Uprated engine 19.4lbs minimum

I don't have the 2003 GCR to hand at the moment, but I'm sure someone will correct me if it's different.

So is this the good news or the bad news?

James

[Dave Hopple]

I feel it is good news James, less rotating mass on our crankshafts should help the relability issues of our engines. Yeah I'll (we all will) have to pull the motor, big deal, if racing was easy, everybody would be doing it

I don't have a current GCR in front of me either, but flywheel weight right now is #18.9 (uprated)and after 10/1 it will be # 15.5

Bad news is (IMHO) page F-272 item 4 under club racing about the 2 year seat belt rules.

Also on the next page f-273, item 5 is interesting about changing the rule on National class status particpation numbers, not sure if that is good or bad news.
-Dave

[TA Treat]

James,
You are required to run a 19 pound flywheel since you are in Spec Ford, not in Formula Ford

[Shep]

Okay,

So the car isn't together yet and I'm getting pretty adept at installing and removing the engine. I did a quick web search for JAE and didn't come up with much.

Where does one obtain a JAE 15.5lb flywheel?

[Dave Hopple]

http://www.jaeparts.com/ and I'm pretty sure Jay Ivey did the sourcing on this part, I would suggest calling him, you can find his phone # in SportsCar magazine under engines etc.

I would also suggest that you contact your engine builder and seek their advice. I'm planning on sending my current flywheel in to Tom Andresen to meet the new weight specs this winter.-Dave

[size="1"][ August 26, 2003, 04:17 PM: Message edited by: Dave Hopple ][/size]

[Chris Campbell]

I'd think you'd be hard pressed to get one of those "Not yet legal" Flywheels from any reputable engine builder before 2004.

[Garey Guzman]

Chris,
Aren't these changes are in place as of 10/1/03?

Regarding the harnesses, which belts meet the "FIA specification #8853/1985, including amendment 1/92" since it says, "FIA driver restraint systems shall be no more than five (5) years old." I see Willans complies. Good, I like the set I have but they expire at the end of the year anyway.

[Dave Hopple]

Went and looked at my Willians belts last night (bought last Feb dated Nov 02.) they have SFI tags which says SFI 16.1 and FIA tags with FIA D-111.T/98 and FIA D-108.T/98 ironically on the back side of the FIA tags, it sez, good until 2007.

They way I read this is... I'll have to buy new belts for the 05 season.

It also says in Fastrack that techincal types of rule changes will be made in October instead of January (the date in which a rule goes into effect)to give time to get things made/ordered installed before the Jan-Feb early season races.

-Dave

[Greg Mercurio]

Dave: If you're really going to replace those Willans, send them to me, I'll be happy to use them until they expire. The FIA D-111.T/98 and FIA D-108.T/98 are equivalent to the FIA 8853/98 specs and are good until the 31st day of the year of expiration. Sez so in the fine print my friend.

Cut the SFI tags off and use them until visual inspection deems them unfit for use.

Hmmmmmmm, wonder why US made (SFI) replacement every 2 years, and foreign made (FIA) every 5? Protecting US manufacturers?

Obviously, the vast majority of input favored the 2 year rule, according to FasTrak anyway. Wonder who voted for retaining the 5 year rule.

gm

[Dave Hopple]

Greg, Yeah I read it that way also, but were not talking about cutting tags of a sofa cushions here are we? The SFI 16.1 tag on my willians has the MFG month/year date, the FIA tag says good until 07'. Not to pick at the "short hairs" here, but the way the rule is currently written, it has a conflict IHMO.

-Dave

P.S. At least "recommended" was scribbled out

[Curtis Boggs]

Dave,

No conflict, .. if the belt has an FIA tag it's good for five years.

About the flywheel, .. I HOPE everyone doesn't expect the lighter flywheel to stop braking cranks, . .. .. the engine needs a forged crank, .. not cast.

Curtis
RFD

[Joefisherff]

I agree with Curtis, based on all of the headaches people went through to get the cast crank created and produced why didn't they pursue a forged crank instead? No professionally built race motor worth a salt is built with a cast crank particularly if it is going to turn above 6000 RPM. Would the cost have been that much greater or were they afraid that SCCA would not approve it?

[Dave Hopple]

Ok Curtis, Greg, I hear ya, call me skeptical, but 23 years of SCCA membership will do that to a person. A forged crank is already available in the UK, they go for around $1200.00.

[Greg Mercurio]

Dave: Obviously the SFI certification is inferior to the FIA, or it too would have a 5 year life. Sorry, couldn't help myself.

The harnesses were submitted to FIA for certification or they wouldn't have the tags. I's only the whimsy of Topeka that's making the differentiation.

Removing the offensive SFI tags should be no more onerous than a bug on the face shield. I understand your concern, but you should'nt worry about it. Have your wife do it when you're not looking.

I'd much rather have an FIA certification. Their test methods are more in line with formula car environment than ITA/SM/SCCA.

Yahoo to the head gasket, flywheel wins!!!!!!!!!!
This class WILL live longer than us. Who's going into the flywheel lightening business?

[Curtis Boggs]

Originally posted by Dave Hopple:
Ok Curtis, Greg, I hear ya, call me skeptical, but 23 years of SCCA membership will do that to a person. A forged crank is already available in the UK, they go for around $1200.00.

Dave,

Yup, .. there's already a good crank available, .. and not much more then the SCCA crank. My guess is they couldn't make any money from it, ..

Other problem, .. the cast piston.Talking to JJ ( Justice race engines ) he said he holds his breath every time he installs those pistons.

Heck, .. my 11,000 rpm chevy comp engines lasted longer then a 1600, .. ..

Curtis
RFD

[LFFR]

3. Pocketing of the piston valve reliefs is allowed up to a maximum of .050" to obtain the minimum combustion chamber volume.

What exactly does "pocketing" mean? Maintaining the size and shape only cutting the reliefs deeper????

John Mihalich, Jr.

[John Merriman]

Yes, that is the correct interpretaion, John. With deck dimensions getting tight on some much-used blocks, the proper rules-mandated compression ratio at 9.3 to 1 can be maintained by this increase in pocket dimension.

[bob darcey]

That ruling qualifies as good news, too. Roughly, the .050" increase in valve pocket depth translates to about .010" equivalent deck height, so a lot more blocks will be legally usable. Should be a lot easier than adjusting rod lengths, and maybe a tad more power with lighter valve springs??

[James Hakewill]

You are required to run a 19 pound flywheel since you are in Spec Ford, not in Formula Ford

Don't give me that old nonsense Tim - you're trying to mess with my brain, you tricky trickster!

There's nothing in the Spec Ford rules about engines!

James

[TA Treat]

Hey, I put the smiley in there! I am looking for anything to stay in front of you. I hope you didn't read the region rules to figure out that I was pulling your leg.

[mblanc]

"Roughly, the .050" increase in valve pocket depth translates to about .010" equivalent deck height, so a lot more blocks will be legally usable. Should be a lot easier than adjusting rod lengths, and maybe a tad more power with lighter valve springs?? ""


I have to disagree.

the piston valve pockets are approx .360 wide by 1.375 long

the cc's increase of one pocket being machined .050" would be calculated as follows:

.360 x 1.375 x .050 x 16.39(to convert " to cc's)
= 0.406 cc's

x 2 valve pockets in a piston = only
0.812 cc's, max compressed volume reduction by machining.

Now compareing that to the bore:
Pie are square, so (3.189/2) squared x pi x .001" x 16.39 = .131 cc per .001" of deck height.
So for .010" = 10 x .131 = 1.310 cc's

No, using the max of .050" pocket machining is NOT worth .010" of bore, it's only worth about .006" of "over decking correction" to keep your compression ratio legal.

It's a nice improvement to have this option, but were talking about LESS THAN ONE cc change in compressed volume! So it's not much. They should have allowed .100", and more blocks could be saved, and be kept legal all at the same time.

Since the pocket machining is to correct for an overdecked block anyway, there is no way you could develop "maybe a tad more power with lighter valve springs??" since the correction puts the valve to piston clearance back to where it should have been on a block with the correct deck height.

Thanks to everybody involved to get these changes passed. They are definitely steps in the right direction for our rules.

Marc

[Greg Mercurio]

First, thanks to Jay Ivey and John Merriman, who really pushed this effort along, and thanks to all of those who actually DID send emails to the CB to get thes items passed. Sven, up yours!

Tim, James, needlessly I remind you that we have a Double Points Regional in October, after the effectivity date. You can bet that some of us will already have that 15.5# flywheel installed. Now that's a lot of rotating mass to lose.

[bob darcey]

Sure lucky I used the word "roughly",huh??
Whether the gain is .006" or .010" (and no one is going to nail this precisely by measuring the straight length of a curved, irregular shape), the rule is a step in the right direction. In fact, it passes a major hurdle by recognizing the problem.

There's a real limit to this approach, and I think the .050" rule is about right. If it were .100" (to correct a .012" over-deck), the piston would be 8 thou or so off the head, which is way too close for my comfort level.

A minor aside, dropping the valve pocket 50 thou to alleviate a 6 thou over deck gives an additional 44 thou valve-to-piston clearance. Your comment, "since the correction puts the valve to piston clearance back to where it should have been on a block with the correct deck height" is wrong.

[size="1"][ August 29, 2003, 03:58 AM: Message edited by: bob darcey ][/size]

[mblanc]

Bob,

I concede, you're absolutely correct about the increased valve clearance, though I would still debate against any possible hp gain.

And yes, it was only a minor disagreement of the .010 vs .006", but an important one. Of course you could say the figures vary by 40%, a pretty high margin of error.

I think you're being too conservative by worrying about piston/head clearance at .048" (your figure of .008" deck ht. after a .100" pocket clearance + .040 gasket)

Even allowing an additional .050 up to .150" of valve pocket machining = losing another .006" would leave your figures of a deck ht. of .002", + .040 gasket still leaves .042" head to piston clearance, which would be plenty in my opinion.

For those thinking "what about the .100 clearance rule of thumb" or the " 0.010 per 1000 rpm rule of thumb" I've always heard about, generally that applies to valve to piston clearance, which is not what were talking here. And as Bob pointed out, that clearance just increases w/ more maching anyway.

I agree it's not an exact measurement of the odd shaped area, but it's hard if not near impossible to consistently measure to a .1 of a cc anyway.

I think we still agree in general theory though. It was a good improvement in the rule, that makes sense, will save blocks, and money.

It's still less than 1 cc compressed volume we're talking about. Two cc's to move around would have been better.

[bob darcey]

Oh yeah, the head gasket...
You are right, I am being too conservative. Recalling that the Cortina configurations we used to build ended up with the piston proud of the deck to get to 10:1, 100 thousandths (vs, the .050" in the new rule) would be fine. Maybe it's OK that this card remains in the deck.

[neildrake]

Dudes,
BTW: I just phoned JAE and they will not have flywheels until October sometime. Sounds like the price will be between $150 and $200 and they will already be machined and drilled for a 7.25" clutch
Neil

[Shep]

Hmmm,

That's not the impression they gave me (four days ago) - they said they wouldn't have *information* until October, which lead me to believe that the actual flywheels were much further off in the future. I like your news better...

7.25 Tilton clutch?

[neildrake]

Shep,
7.25" Tilton or QM clutch or equivalent...ie the step will already be machined.
Neil

[Neil Porter]

If you can get a new flywheel with a ring gear machined and balanced for $150 to $200 that will be the way to go. I have started lightening flywheels to the new weight for my customers and by the time they are machined and balanced it cost about $150. Neil