By Skip 

The information here is for reference only or information only for members of Bracket Masters Racing Team, Inc (BMRT).  It is the personal opinion of Skip Holbert, for use by BMRT members.  Skip is not responsible for any damage you may incur by using anything here that may cause you to damage your equipment, no matter how large or small the damage.  If you have a comment about anything written here, 
please contact Skip at: oholbert@bellsouth.net  -  4/13/06

These random questions are from members or friends of Bracket Masters Racing Team.  Skip answers them to the best of his knowledge.  (Read the Disclaimer above!)

Question:  What should I do about low starter voltage?  Another way of asking the same question:  
My engine will not turn over fast after the first or second start of the day.  The starter has been changed and it still won't start consistently.  What can I do?   All of these questions come from racers that have moved the battery to the rear of their race cars or trucks. 

The cable run on the vehicle, from the battery to the starter, is too long, and the size of the cable is too small.  After that cable gets hot from use, the resistance increases and the starter does not get enough voltage to turn the starter and the motor. 

1.  The batteries, located in the rear,  need to be close to the emergency switch.  The emergency switch is required if the battery has been moved.  
2.  The emergency switch should be as close to the battery as possible.
3.  The cable run from the Emergency Switch up to the Starter Relay should be at least #0 gage wire.  
It should be a continuous run of cable from the Emer. Sw. to the starter relay, if you use a relay. 
4.  The wire from the Starter Relay to the Starter should be the same size as the new cable from the switch to the relay, #0 gage.
5.  The Negative cable from the battery should go all the way back to the engine block!!!  Many people will say that this is not necessary, but believe me, it will work BETTER.  Connecting the ground to the Truck Frame will work, but not as well as connecting it to the Engine Block.  This ground connection should be the same size as the new cable, #0 gage wire. 
6.  The Positive cable from the battery to the Emer. Sw. should be the same size cable too, #0 gage.
7.  Make SURE ALL connections are CLEAN and TIGHT.  Clean them frequently during the racing season.

Normally there is nothing wrong with your starter.   It is ALL a matter of increasing the voltage to the starter. 

Question:
I have a question for you about my motor that we just put back together.
We had the crank polished and we installed the oil pan with the windage screen and crank scrapers.
The oil pressure is normal when driving, but when I stop the car at a light, the oil pressure drops much, much lower 
than it ever has before.  It returns to normal once the car starts moving again.

Is this something that is common with this type of pan, or do you think that there may be too much clearance 
between the crank and the bearings now?  I am using 20w 50 racing oil. Should I use heavier oil?

ANSWER:

What do you call much lower oil pressure?

A well clearanced racing motor, Small Block Chevy (SBC), should be able to run 30W racing oil and have around 
22-25 PSI of pressure at 700 - 900 RPM, with the engine warm, around 170 - 200 degrees F.  You should not have 
to use 50W racing oil in a SBC that has just been properly built.  

The rule of thumb for SBC oil pressure; you should have at least 10 PSI for each 1000 RPM at all times 
(1000 RPM = 10 PSI, 7200 RPM = 72 PSI).  If you meet those criteria, you are OK.  If you have to put 
heavy oil in it to get there, you are OK, but you will cut your HP production of the engine by using the 
heavier weight oil.  Warren Johnson, of Pro Stock fame, uses synthetic 30W racing oil.  He recommends 
no higher than 40W conventional oil in a racing motor.  The use of 50W oil is an old racer theory that has 
been passed on, that should be put to rest.  I have used straight 40W racing oil in my SBC motors, here in 
Louisiana in the Summer, for years.  In the Winter, I use straight 30W oil.  I have run as low as 18 PSI on 
the return road with the motor at 220 degrees F.  When I would punch it, the pressure would go up and maintain 
my 10 PSI per 1000-RPM standard.  

Synthetic oil is a much better choice for racing.  Use conventional oils for the break-in period of the motor 
(with plasma-moly rings, this period is only one trip to the track).  You can also seat the rings (P-M only) 
by completing the following, three times: Warm the engine to normal operating temperature, no high revs, 
turn off engine and allow the engine to cool back down to ambient.  Do this three times.  After that, 
the rings should be seated.  Dump the conventional oil and put synthetic oil in the motor for long bearing life.

I have only lost one SBC motor from bearing failure and that was after many years of running the motor and 
THEN switching to another well know Racing Oil in 1993.  I also lost one MOPAR motor to bearing failure 
back in the 70's after switching to that same brand of Racing Oil.  I now use either Havoline conventional oil, 
Mobil 1 motor oils.  I have never had a problem with either of these oils. 

In the Summer, I use Mobil 1,  4qts. of 10W-30 + 3qts of Mobil 1 10W-50.  In the Winter, I use all 10W-30. 
The reason I mix it?  The 40W synthetic oil is very hard to find.  

In September 2001, when we went into my motor because of the filter failure, the bearings were in such good shape, 
we did not change the bearings.  That was after 200 runs plus dyno time.  This is a BBC and it had run as low as 20 PSI with 
the collapsed filter.  Now it runs at about 42 PSI on the return road at 200 degrees at idle of around 800 RPM 
(82 PSI on start, when cold).

Question:
Is it true that Multi-Viscosity oil gets thinner when it is cold?  Is it normal for the oil pressure to be lower after 
having the crank polished?

Answer:
Yes the Multi-Viscosity Oil gets thinner when cold.  That helps to get the engine started (turning) in the low temp. 
areas of the country.  Do you believe my Ford Focus' recommend oil is 10W-20?  It scares me.

If you think about what is happening when you polish a crank, and use the same thickness bearings on those 
journals, the oil pressure has to go down.  If you polish and then change the thickness of the bearings to get 
back to the recommended clearances, then the oil pressure should be at the same place as it was when the 
motor was new.  Did you know they make bearings that are +.002 and +.003 for those reasons (I may be off a 
little on the available thicknesses, but they do make aftermarket bearings to recover clearances).

Question:
What is a good method of adjusting valves?

This information comes from the 1997 LUNITI CAMS catalog, in an article entitled, "Valve Lash - Setting it Right, 
Once and for All".  All racers that do their own work should get a copy of a recent (or old) Luniti Cams catalog.  
They print a wealth of information on valve train setting, selection of components and how to set and check clearances 
of all the different components in the valve train.  There is a treasure chest of information on tuning SBC and BBC 
engines (read spend more money with Luniti :>) Since they are now a Holley subsidiary, I don't know what the 
new catalog looks like.  Look them up on the internet and order a catalog, it will be well worth it.

Question:
Why does that racer have a two-digit or single digit number on his window?  I thought all of us had to have 
4-digit numbers or numbers and letters.  

Answer:
When you pull into the staging lanes and you see a low number on the car you are about to run, one or 
two digit, you can rest assured that you are in for a close race.  (This answer is close to the correct answer.  
NHRA has changed the rules a little. Professionals can now purchase a 2-digit permanent number). 
NHRA reserves the first 9 (or so) numbers in each class for the cars that fall into the first 9 positions in the 
national standings in that class, like, F/C 1.  This is the #1 Funny Car Driver in the nation  
Each division also reserves those first 9 numbers for the divisional racers in each class that have earned there 
place in the top 9 drivers in their class.  If you are in Division 4, your first number is always 4 (unless you are 
one of the lucky drivers that falls into the above national category). After the first number will be either three 
more numbers or letters and numbers.  A division 4 driver that is number 3 in the Super Gas category would 
wear S/G 43 on his/her window (I got beat by this guy in Houston din 2002, that's why I remember it).  
To compete in a divisional or national event, you must have a permanent number.  You must have a permanent 
number for each class that you compete in.  See National Dragster or the NHRA rule book, General Regulations, for more on numbers.  Also see Gen. Regulations for placement and size of numbers. 

Question: 
I loosened my valve lash ( loose .020").  Should I have to change the carb. jetting at the same time?

Answer:
Only make one change at a time.  That way you know what the change did.  I would leave the jets alone and try 
a couple or three lash changes, until it slows down; .020", .022" .024"( you may see ET changes with no MPH 
change, or vice versa).   Make a run and check the plugs after each lash change and see what's going on.  
Then change the jets to compensate for any need to richen or lean the motor.  Do the same thing for jet changes.  
Make one change at a time.  You are recording all of this in your log book?  I hope you keep some type of notes 
on changes and the effects.  You always want to be able to go back to your original configuration.  How do you 
know what that is?  You keep notes!  I keep my notes on my time slips, them transfer them to a book.

Question: 
I changed my springs to lower the seat pressure after breaking a valve.  Another broken valve occurred after 
installing the new springs.  Do you think I went the wrong way?  (The person that asked the question found 
this information in a 1999 posting on the National Dragster Web Site).  It is reprinted here for your information:

Technically Speaking
The spring's the thing

by David Reher

In the last two months, I have discovered a new kind of power: the power of the press. I've worked with mills, lathes, and hones for 30 years, so it was a real challenge for me to sit down at a word processor and begin my second career as a writer. I genuinely appreciate the comments and compliments I have received since I joined the ranks of National DRAGSTER's back-page columnists.

My sense of humor is no match for Bob Frey's, and I can't offer any insights into the human condition as do the Rev. Ken Owen and Dr. Jeremy Torstveit. I do know a little about building engines, however, and that is going to be my subject. I promise that I won't deluge you with theory and analysis; my intention is to offer practical advice and real-world recommendations based on my own experience.

I don't make any claim that my word is gospel — I'll leave that to the good Reverend. Other engine builders may not agree with my opinions about particular parts and procedures, but I know what works for us at Reher-Morrison Racing Engines.

I always advise racers to consider the long-term costs and consequences when they are buying engine components. Parts that are initially inexpensive can be very costly to maintain over the course of a season. For example, a flat-tappet camshaft is much cheaper than a roller cam and lifters — but in the long run, a flat-tappet cam can be a black hole that sucks up dollars.

Flat tappets may be fine for street engines, but I don't recommend them for any serious racing application. Sure, NASCAR Winston Cup engines have flat tappets, but that is because the rulebook requires them. We have built several NASCAR motors, and the extra work it takes to make flat tappets live in a racing environment is a real pain. The tappets must be precisely positioned on the tapered cam lobes to make the lifters rotate. If the tappets don't spin properly, they will wear the lobes flat almost instantly. A flat-tappet cam must be broken in with light-tension springs, which involves the extra expense and effort of switching to heavy springs after the break-in period. Finally, there is an absolute limit to how much spring pressure a flat tappet can withstand before it galls the camshaft and turns itself blue.

The odds are against any production block having every lifter bore in the right position and at the correct angle. NASCAR engine builders use elaborate fixtures to machine the lifter bores perpendicular to the camshaft centerline and to position the lifters accurately on the lobes. Many also install jets in the oil galleries that spray oil directly on the cam lobes.

It simply does not make economic sense for a bracket racer to prepare a block to NASCAR standards in order to use a cheap flat-tappet cam. And if a flat tappet fails or the cam goes flat, the cost of repairing the engine would have paid for a roller cam and lifters in the first place. For anyone racing a hard-running bracket car every weekend, I believe that a roller cam is the only way to go. The money you save in the long run makes the roller cam an excellent investment.

The most common mistake I see in engine building is to use valve springs with inadequate pressure. Not all springs are created equal; just because a set of coils is described as "roller springs" in a catalog or advertisement does not mean that the springs will produce enough pressure to do their job.

Several misconceptions about valve springs influence racers to make poor decisions. A customer who says, "I don't need good springs because I'm running stock valves," is badly mistaken. Steel valves are heavy, and adequate spring pressure is absolutely essential to control their motion. A valve's inertia increases with the square of the engine speed, so even a small increase in rpm requires significantly more spring pressure to maintain valvetrain stability.

It is a myth that stiff springs will pop the heads off valves or cause valve tuliping. The only time that the valve head is subject to spring tension is when the valve is closed and resting on its seat. At all other times, the valve sees only a compressive load between the tip of the valve stem and the groove for the valve locks. In our Pro Stock engines, we use 7-inch-long titanium valves with tiny 7 millimeter stems and springs that exert more than 1,000 pounds of open pressure — and we've never broken or tuliped a valve due to high spring pressure.

In fact, too little spring pressure is almost always the root cause of valvetrain failures. We spent a year studying valve springs using an Optron, a sophisticated electronic device that can precisely record valve motion and reveal valve float. We learned some shocking truths about valvetrain behavior at high rpm. Even with a relatively mild camshaft profile, the valves bounce on their seats before they close. If the spring is too light, the valve bounces uncontrollably. The valve hits the seat, rebounds, hangs in the chamber a while, then bounces erratically several more times. Imagine how hard this is on the valve and the rest of the valvetrain!

Even with high-pressure springs, the valves still bounce when they close. The crucial difference is that the bounce is controlled and predictable, like dropping a basketball. The valve bounce diminishes progressively, and generally, on the third bounce, the valve stays closed until the next cycle.

The evidence is unmistakable when we tear down an engine that has been run with weak springs: The valve seats are usually beaten up, the valve job is wiped out, and there is fretting on the valve faces. It's fortunate when we catch these problems early because weak springs will almost certainly cause a catastrophic failure.

Another excuse I've heard for not using stiff valve springs is that they take more horsepower to compress. My reply is that each spring stores energy, and for every valve that is opening, another one is closing. Anyone who has been whacked by a torque wrench while turning a crankshaft can testify that the valve springs exert considerable force on the closing ramps!

I have never installed stiffer valve springs on an engine and lost power; the improvement in valvetrain dynamics more than offsets whatever additional power is required to overcome the springs' resistance.

I think that any serious big-block drag racing engine should have at least 220 pounds of seat pressure after it has been run. While 1.550-inch-diameter chrome-silicon springs may have adequate pressure when they are installed, they eventually fatigue and lose their tension. We use 1.625-inch-diameter Vasco Jet springs exclusively on our Super Series engines and big-block cylinder-head packages. These are the same springs that we used in Pro Stock engines just a few years ago; we have virtually eliminated valvetrain breakage in our bracket racing engines by installing these high-pressure springs.

For my money, peace of mind is worth the cost of premium valve springs in any drag racing engine.

On a personal note, I would like to thank the readers of National DRAGSTER for the many thoughtful expressions of sympathy we received after the death of Buddy Morrison. Buddy was truly an exceptional individual, and I am proud that he was my friend and partner for 30 years. On behalf of Susan Morrison, Buddy's extended family, and the entire staff of Reher-Morrison Racing Engines, I thank you for your condolences and prayers.