Author Topic: How do I make my engine Better? Racing Engines 101 . . . . .  (Read 41635 times)

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Offline fordboy628

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To anyone searching this thread,

I've deleted all of my original content on this older thread.   Sorry for any inconvenience this may cause you.

 :dhorse:
Fordboy
« Last Edit: May 13, 2016, 12:36:06 PM by fordboy628 »
Science, NOT Magic . . . .

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"There is nothing permanent except change."    Heraclitus

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Offline wobblywalrus

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Re: How do I make my engine Better? Racing Engines 101 . . . . .
« Reply #1 on: July 23, 2014, 11:38:41 PM »
This looks like it will be an interesting subject.  It is nice of you to take the time to type it up.

Offline SPARKY

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Re: How do I make my engine Better? Racing Engines 101 . . . . .
« Reply #2 on: July 24, 2014, 10:46:12 AM »
I just wish that this was being dealt with a much younger more SUPPLE mind--- :-o  I feel a brain stretch coming on---lol
Miss LIBERTY,  changing T.K.I.  to noise, dust, rust, BLUE HATS & hopefully not scrap!!

"Security is mostly a superstition. It does not exist in nature, nor do the children of men as a whole experience it. Avoiding danger is no safer in the long run than outright exposure. Life is either a daring adventure or nothing."   Helen Keller

We are going to explore the racing N words NITROUS & NITRO!

Offline Peter Jack

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Re: How do I make my engine Better? Racing Engines 101 . . . . .
« Reply #3 on: July 29, 2014, 07:33:49 PM »
One of the best books I ever read was Waddell Wilson's book on assembling each of the big three stock car engines. It's hugely dated and only dealt with those three specific engines, but he emphasized over and over the importance of measuring everything several times and checking all clearances before ever doing the final assembly. He also emphasized the fact that it should take a good amount of time to put a good racing engine together. The philosophy works!

Pete

Offline Milwaukee Midget

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Re: How do I make my engine Better? Racing Engines 101 . . . . .
« Reply #4 on: July 29, 2014, 10:24:35 PM »
He also emphasized the fact that it should take a good amount of time to put a good racing engine together. The philosophy works!

Pete

Engines are funny, in that if you're moderately competent, you can usually screw one together and it will likely work.

But there is no "one thing" that makes for a good race engine.

I'm still an amateur at putting together an engine, which makes me inherently slow, but going slow s l o w l y uncovers the problems.  This often leads you to taking it apart, which gets you better at putting it back together again.

And then there are the questions that come up that you don't know are questions.

Measuring everything is important, but I've discovered, under Mark's tutelage, that things you wouldn't instinctively measure for a simple re-build of a stock engine are often the critical items that you must measure for a race engine.

The work of others, regardless of their competence, expertise or experience, are often the things that need the closest scrutiny.

Yes, it's time consuming.  To do it right, you may have to skip an event - which I learned is a better proposition than doing it wrong and gnashing your teeth all the way home.  Seat time is fun, but only in a proper running ride.

Mark's made me a believer in dyno testing - for 2 reasons:

A.  You can dial in a tune much easier on an exposed engine in an air conditioned shop than you can bent over under a tarp on the salt in 95 degree heat.

B.  It's better to solve the problems at home, where you have all the resources and contacts at your disposal to deal with them, rather than 1600 miles away, where you're at the mercy of a late running UPS truck.
"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Offline wobblywalrus

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Re: How do I make my engine Better? Racing Engines 101 . . . . .
« Reply #5 on: August 06, 2014, 12:48:42 AM »
There are a few things that can be done.

Radius and polish the lower edges of a new set of keepers.  This will reduce the amount and magnitude of stress risers.

Check the valve spring tension and replace weak springs.  This type of failure can be attributed to valve float.  The valve slams onto the seat rather than following the cam and gently closing.  This puts a shock load through the valve, springs, keepers, etc.

Calm down with the right foot.

Reduce the number of load cycles.  Limit the runs down the track to the minimum needed to do the job.


Offline kustombrad

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Re: How do I make my engine Better? Racing Engines 101 . . . . .
« Reply #6 on: August 06, 2014, 01:09:35 PM »
Wow! Very well written and lots of little details covered! One thing that wasn't mentioned for the longevity of a race engine is just time it's actually rotating. I'm still with the thinking of going through the lights, push in the clutch and kill the engine . Using the engine for slowing and stopping puts wear and stress on parts that could have been used for MORE passes under power! I see guys do that all the time and don't understand their thinking. Plus if you shut it right off, you can look at the plugs and see what's going on. This is just my opinion...

Offline SaltRat

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Re: How do I make my engine Better? Racing Engines 101 . . . . .
« Reply #7 on: August 06, 2014, 10:11:33 PM »
Cubic Money, common sense (brad has a good idea), more cubic money.

reapply cubic money as necessary.

am i a smart ass? maybe . . .  no offense intended.
SaltRat
When (if?) this baby hits 88mph, you'll see some serious poo.

Offline wobblywalrus

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Re: How do I make my engine Better? Racing Engines 101 . . . . .
« Reply #8 on: August 08, 2014, 01:10:59 AM »
Bike racing can be done at reasonable cost...until you crash.

Offline tauruck

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Re: How do I make my engine Better? Racing Engines 101 . . . . .
« Reply #9 on: August 08, 2014, 03:32:36 AM »
Saltrat has definitely "been there". :-D

A quote from the guy that ran the Mercedes DTM operation was that if you had enough money it still wasn't enough!.

If it was cheap everyone would be doing it.

I'm not a designer but a good assembler (I hope) and cleaning before assembly is most important.
I wash the stuff, chase threads, blow out all the holes and just keep going until there is no residue.

Having a good mentor also helps. :-D

Offline wobblywalrus

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Re: How do I make my engine Better? Racing Engines 101 . . . . .
« Reply #10 on: August 10, 2014, 02:00:58 AM »
On the subject of busted keepers...

Years ago the valve head seperated from the stem on a Honda engine I built.  Others were having the same problem.  After-the-fact investigations pointed to annealed valve springs as the culprits.  Honda tend to rum hot and their design and metallurgy was not the best at that time.  What I learned was to check valve free length, compressed length, and tension at every tear down.  This includes checking new springs.

Another thing to look for when a keeper breaks is pack length.  Is the valve spring fully compressed, or packed, at any time?  This can break a keeper.

Spring harmonics can be a problem.  This is when the natural frequency of the spring matches the frequency of the cyclic external loads.  Surging can occur through the spring and it creates additional forces on the valve train.  The preferred valve spring setup for my engines is a two spring setup with the inner and outer springs wound in different directions.  What I am trying to do is have a spring setup where, if there is surge in one spring, there is not in the other.

Offline dw230

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Re: How do I make my engine Better? Racing Engines 101 . . . . .
« Reply #11 on: December 09, 2015, 02:51:26 PM »
A)  4 valve cylinder heads flow pretty well at low lifts, but there are some modest increases that can be gained with careful work.
2)  "Dogleg" ports are not the ideal.   But you probably don't get to fix that.
d)  Small increases of size and % of valve throat diameter can dramatically alter the flow.
z)  Concentrate your efforts on the lift range that gives the best gains.

Aren't these statements common knowledge among engine builders and racers in general?

DW
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Offline Milwaukee Midget

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Re: How do I make my engine Better? Racing Engines 101 . . . . .
« Reply #12 on: December 09, 2015, 10:06:22 PM »
I'll take a stack of spreadsheets over a box of shiny, unusable parts any day.

"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Offline Speed Limit 1000

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Re: How do I make my engine Better? Racing Engines 101 . . . . .
« Reply #13 on: December 09, 2015, 11:41:45 PM »
I'll take a stack of spreadsheets over a box of shiny, unusable parts any day.



Shiny? Hell sometimes our parts looked like :-o Scoria
John Gowetski, red hat @ 221.183 MPH MSA Lakester, Bockscar #1000 60 ci normally aspirated w/N20

Offline wobblywalrus

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Re: How do I make my engine Better? Racing Engines 101 . . . . .
« Reply #14 on: December 10, 2015, 11:12:12 PM »
Mark, what is your opinion on ceramics?  The engine is a twin cylinder Triumph with air/oil cooling.  This is what I was planning to do and the reasons.  Am I correct in my thinking?  The exhaust tracts, piston crowns, and combustion chambers will be ceramic coated to reduce the rate of combustion heat transmission to the engine structure.  This way, I hope to keep the engine a bit cooler since it has a hard time shedding heat.  The intake tracts will be ceramic coated and the intake valves polymer coated to reduce the rate of heat transmission from the engine to the intake charge.  By doing this, I hope to maintain intake charge density.  I am not sure if anything needs to be done to the exhaust valves.