Welcome to Bob’s Blog! This is where Bob will post tips, tricks, and experiences he has with other racers. Check back often to read what Bob has been up to.

Fuel Injection Anti Backfire Trick

Wednesday, January 13th, 2021

If the high speed bypass poppet is located after the barrel valve, it will shut whenever the throttle is lifted for an out of shape run.

That will return the engine to the rich AFR momentarily when the throttle is hammered back on. The enrichment is useful to decrease the chances of a momentary lean condition from throttling under load. A momentary lean condition can cause a backfire that is reduced by this method.

Some fuel system standard layouts provide this location.  Enderle is an example.  Others locate the high speed ahead of the barrel valve.  Rons and Hilborn are examples.  This protection is not provided by that layout.  For MFI setups with a barrel valve separate from the nozzle distribution block such as an old Crower, move the high speed bypass connection after the barrel valve, in the connection line or an added output in the distribution block.

For MFI setups with a barrel valve and distribution block that are a common assembly such as Hilborn, an added port in the distribution block location can be done to move the high speed bypass to this location.

Spectacular New Engine Developments Applicable to Racing

Monday, November 23rd, 2020

Some new highway engines sport a dramatic change to camshaft timing for improved efficiency, emissions, and performance. Each of these apply to high compression ratio engines. However, they rely on special camshaft timing to reduce the compression ratio to retard pre-ignition. An increased expansion ratio from a higher compression ratio remains that achieves improved engine performance & power. Each of these have application to racing engines that are common with mechanical fuel injection.

Miller Cycle

This method applies to a high compression ratio engine with a supercharger. The camshaft is designed with a late closing intake valve. That allows some of the intake to be pushed back into the intake manifold. This reduces compression ratio to avoid pre-ignition. It makes the same effective compression ratio as a smaller engine with a lower compression ratio. However, it is done with a larger engine with a high compression ratio. When the power stroke occurs, a higher compression ratio with a larger expansion ratio causes more efficiency & power.

Some fuels that are used in supercharged engines are detonation sensitive. Certain provisions are used to limit detonation. One is a reduction in static compression ratio. Another is to limit the amount of supercharger boost.

Nitromethane is a good example. In Nostalgia blown nitro drag racing, compression ratio is typically reduced to only 6 to 1. Class rules limit blower size, overdrive, and fuel pump size. Long intake duration camshafts are typical in this class. One of our customers previously used a short intake duration camshaft and experienced a lot of pre-ignition. This is sort of an example of tipping out of a partial Miller cycle domain. A later closing intake from a longer duration camshaft was subsequently used. It caused favorable reversion, less compression ratio, and less pre-ignition. It was making the engine essentially a smaller size in the intake stroke with a reduced effective compression ratio, reducing pre-ignition. Yet, the engine remained the full size and expansion ratio for maximum power. Camshafts in the 290 degrees duration @ 0.050 inches lift are typical of the long duration camshafts in this class.

Through the years, I saw at least 3 different motorsports applications with camshaft intake duration over 300 deg. which is quite high. Although they were not concisely Miller cycle engines, these suggest an examination of longer camshaft duration with a later closing intake such as these. Combine that with a larger engine and higher compression ratio. Favorable results in Nostalgia blown nitro drag racing could be expected. Intake reversion from the Miller cycle also increases fuel turbulence and dwell time, increasing vaporization for more power.

If added camshaft intake duration provides decreased pre-ignition, additional spark advance or nitro percentage may also work for more power. Our added oxygen to fuel ratio determination in our ProCalc jetting calculator provides precise numerical control of the tuning for this setup change for differences in nitro percentage, blower overdrive, and weather.

Gasoline with a blower is another great application for the Miller cycle. We have fuel injection setup info in our publications with our ProCalc calculator to assist with this combination.

Next is a summary of two other methods of dramatic camshaft timing change for more efficiency & power.

Atkinson Cycle

  • Normally aspirated engine with a late closing intake valve with high compression ratio
  • same effective compression ratio as a smaller engine with lower compression
  • for reducing pre-ignition
  • larger expansion ratio from a higher CR for more efficiency & power.

Budak Cycle

  • Normally aspirated engine with an early closing intake valve with high compression ratio
  • same effective compression ratio as a smaller engine with lower compression
  • for reducing pre-ignition
  • larger expansion ratio from a higher CR for more efficiency & power.

Further evaluation of these two alternatives for racing applications will be provided in our
subsequent publications.

New blown alcohol fuel injection jetting manuals

Sunday, November 22nd, 2020

We are developing jetting manuals for blown alcohol racing; any suggestions:

  • racing type: drag racing, land, water, high speed, tractor pulling, …
  • Roots blower size: 6-71, 8-71, … 14-71 …
  • low cost setups: 10k, 15k, …
  • high horsepower setups: 2,500, 2,800, …
  • overdrive: 1/1, 10%, 20%, …
  • altitude: sea level, high altitude, …
  • any other needs.


Bad Advice about Tire Shake

Monday, November 9th, 2020

Years ago at a drag strip in Michigan, I was testing my funny car dragster. I thought it had a tire shake problem. Some macho passerby’s in the pits said “If you can’t drive through tire shake, you don’t belong behind the wheel!” The next run, I launched and the vibration was so bad, I could barely see. I followed my advise givers and stayed in it to try to drive through it. At 189 MPH and almost blind, I crossed the center line. My car hit the high end cone, taking out half of the body panels. I spent the winter gluing the car body back together. Later, I learned that I had
a tire balance problem. It was not tire shake. The passerby’s advice was inadequate and irresponsible for a new driver/car owner such as me at that time.

Clutch Too Tight; Too Much Shake

Many years later at a track on the West Coast, my funnycar occasionally had tire shake when I
shifted into second gear, and I would let up to regain control

more info:

ANRA Bakersfield Drags Nov 2020

Saturday, November 7th, 2020

ANRA Fomoso, Bakersfield, Ca; Nov. 6,7,8, 2020

Free air density hourly forecast for tuning; historical, metric, DA, AD, water grains; site Map location…ield_Speedway/

Drag Race wins with ProCalc

Tuesday, September 22nd, 2020

Drag racers with very good engine builds and racecar setups who tuned with assistance from our ProCalc / ProTune membership & air density forecasts on

Sept. 19 — Sacramento Governor’s Cup

— 7.0 Pro qualification: Ken Fullerton; tuner >> Kim Lee qualified low @ 7.01 on 7.00 index

— 7.0 Pro winner: Ken Fullerton; tuner >> Kim Lee; elimination results with consistent performance: R1: 7.059, R2: 7.076, R3: 7.015; R4: 7.008

— CIFCA qualification: Tony Trimp; tuners >> Harvey Williams & Chad Chinen qualified low @ 5.95 on a 5.90 index

— CIFCA winner: Tony Trimp; tuners >> Harvey Williams & Chad Chinen; elimination results with consistent performance: R1: 5.96, R2: 5.929, R3: 5.967

Sept. 20 — Sacramento Heritage Series

— 7.0 Pro R/U: Brad Denney; tuner >> AA Fred Merrick; elimination results with consistent performance: R1: 7.037, R2: 7.038, R3: partial run on a BYE, R4: 7.091

Honorable mention: Ron Kolb; tuner >> Kim Lee participating in Nostalgia Eliminator Series throughout the weekend.

Engler Fuel Injection on Sprint Car Ford Engine

Wednesday, August 19th, 2020

Our friends at Engler Machine & Tool Co, manufacturers of racing fuel injection, popular in circle racing and other categories that run mechanical fuel injection, scored a win powering the new Ford Sprint Car engine.  Check out this Engine Labs tech article:


Contaminated Hand Sanitizer

Monday, June 29th, 2020

Several hand sanitizers are reported to be contaminated with methanol.  Among those reported on Fox Business News are Saniderm Advanced Hand Sanitizer and several others manufactured in Mexico.  Our 5000 Horsepower on Methanol tech manual has an entire chapter on methanol hazards to skin, lungs, eyes, etc.  It is reported that methanol cannot be made non-hazardous to human exposure, even with sugar additive (occasional ‘wife’s tail’ in the racing pits) or in any other mixtures. (more…)