Cylinder pump procedure - question?

[Peter Jack]

I've seen the ones described by J.D. USAC used to use them to check the bores on the Offy when we were running them in the Indy cars. For some reason I'm having a lot of trouble visualizing what Jack's describing. Come on Jack, have a little pity on us simpletons and give us a slightly more lucid description.

Thanks,
Pete

[JackD]

The hardware to measure the stroke is pretty easy but the bore deal is even easier.
It consists  of a rod (handle) that will go through the plug hole and at the end is a pin that is hinged at the middle but lightened on one end so it hangs at the hinge point like a pendulum.
When it contacts the piston it lays flat.
Remember we measured the stroke with the other tool and wrote it on our hand ?
This pin (1/4 in dia with a round end) is precisely made to the bore limit of the class.
You will feel it get tight against the maximum diameter of the jug and that will tell you the jug diameter is smaller than the class limit.
You can make another one that is the minimum bore size for the stroke you have (important) written on your hand and it will ding like a dinger in a bell.
All of that takes less time than it did to type this.
Now comes the math that includes counting the jugs and the fat fingers on the little buttons of the calculator you got from the 99 cent store.
Mine was made with stainless tubing except the pin that was the shank of a 1/4 stainless bolt.
I spent more time polishing it to a chrome luster than I did making it from available junk.
If you have a lot more time or money you can make a form fitted, velvet lined hardwood case like Ford did but I have only seen pictures.  LOL
The worst part was at the end of the season, Elmo said I finally had to take it apart.
As bad as it was, nobody cared enough to measure it any other way and that is not the bad part.
The bad part was Barry had his Blown Chrysler going back together before I had my little Ford apart and he won't let me forget it.
That was like a slap up side da head but I survived..

[Peter Jack]

BINGO! We're dealing with a go/nogo gauge rather than a direct measurement. It all makes sense now and as you say it's easy to make.

Thanks,
Pete

[JackD]

It is a direct measurement of the pin that won't go ding in your bore.
If you are loosing volume as the Air Pump goes through it's cycle the performance can be improved with a bit of oil in the jug that is just like a dry and a wet leak down.

OBTW: Go easy on the refrence to Bingo, I ain't that old.
 You must be talking about Glenn or Glen.

[russ jensen]

OK I can measure the bore w/ pop gauge through  ports but stroke is problem- would an inspection hole in oil pans -  w/ rod & dial indicator going to piston pass to verify stroke?? are they trusting enough to beleive that all crank throws have same stroke??2nd thought- would measuring from piston top to bottom of oil ring and then benchmark on piston as it is stroked{measure w/caliper through port}  be acceptable??

[JackD]

Where is the plug in relation to the top of the piston and is it straight or angled in relation to the piston travel ?

What kind of a motor is it ?
You can whisper.

[dwarner]

There are three different sizes of the bore/stroke tools available. The motorcycle guys have the smallest one on which will fit through a 10mm plug hole, the car guys have the one which will fit through larger plug holes. We share.

From the rulebook:
Record setting engines which cannot be certified by direct measurement of the bore and stroke or with the SCTA air pump may require special tools. The entrant shall provide any special tooling required to measure an engine. The Technical Committee will certify special tools for accuracy. Any engine that cannot be measured using the SCTA air pump or special tools will require disassembly for direct measurement of cubic inch displacement.

I underlined an important part,

DW

[Carl Johansson]

Plugs are in the center -  so should be ok -  No?

Pulling the head on this 2 smoke is complicated by the fact that it's water cooled -  so I assume it would be messy!

Carl

Carl,

Is the plug in the ccenter of the cylinder? If so, no problem.

Another question I have is, why would someone make a bore tool when it is already available?

DW

[dwarner]

If you plan on dumping water when pulling a head, think Ford flathead, we will seal the engine and let you take it to your pit. An inspector will come to measure the engine when the head is off and the seal is still intact.

You cannot dump liquids on the salt other than PURE water. I don't want liquids on the graound in the inspection/impound area because of the high volumn of foot traffic.

This stuff is not that difficult. We try to make your salt experience enjoayable not advisaral(sp?).

DW

[JackD]

Consider how much water you have in the bike and drain it into a pan.
Look at the USAC tool and be sure their is room for it above the motor and below the frame rails.
If room is at a premium. the handle of your "T" tool can be made in 2 pieces and screw on the additional handle length after it is in the bore.

[Bob Drury]

Dan, a masseus and coctail lounge would help.  Donna's is fifty miles up the hill.  Oh, and a NAPA store on the salt.  Thanx, Bob

[russ jensen]

Where is the plug in relation to the top of the piston and is it straight or angled in relation to the piston travel ?

What kind of a motor is it ?
You can whisper.

its my scratch built eng that have been thrashing on for many years & design changes-  I can talk out loud if you like- 2 plug / cyl @ 90 dg to bore between pistons- would run 4 plugs / cyl but collant  gets in way. Right now its a dbl wedge camber setup- shades of 430 lincoln-409.  how much time is allowed for a teardown as this would be a lenghty process??

[jimmy six]

Russ, All engines must be certified by the end of Speed Week. If you set your record on the last Friday morning better haul the mail to get the engine done before we close up shop. If you do it near the begining of the week there may not be a problem. I do not like a go-no-go style of gauge. I would rather not see a device that cannot prove the ligimacy of the cubic inch of the engine.

The words "Jack D. said on the website" does not carry much/any weight in impounds. He is not there in any capacity to judge an engine. Actually in the last 10 years I haven't seen him at all at Bonneville. Mr. Warner and his designees are the ones in charge. All question should be directed to him. Yes, each of us has measured an engine with the pan removed, not thru some hole. This NOT the preffered method and is very rarely used.

Each of the competitor should feel very lucky the Dan and his group has purchased tools to do this and allow desigated members to seal partially assembled engines. Where I started in 1975, all engines were torn down after the record and before you could change classes.

The motorcycle group handle their own engines and at times we help each other. I do not see them post here. Good Luck...J.D.

[JackD]

Some of you will recall the sequence of events that led up to the tools that are in common use today , the number of records certified with them , and it didn't start with the cars..
Imagine a person set a mark early at Speedweek and the others in the class had to run against the new mark for the rest of the week but it was not measured until the end of the event.
What happened to all the others if the new mark was found to be with a motor that was too large ?
Making it easier to get accurate results is better for everybody and should be the objective.
If you can't use a particular method in Your application that doesn't mean the method is wrong.
Having certified or set records with all the methods at Bonneville and the various LSR sanction bodies, I have a pretty good idea where they are best applied and the racing program continues today.

"Tradition unhampered by progress is it's own reward."

[dwarner]

The other option is that if you set a record early on you may seal the engine and be certified later. This allows you to continue to race. Must be by the end of the meet though. In this case others in your class run against the old mark. A record is not a record until the vehicle is completely certified.

As an example, at the last El Mirage meet last year I had two Mod Roadsters that had upped the existing record. The slower of the two stood by until the faster one was certified. This allowed the slower one to bypass the tear down procedure.

DW