This month, we have an addendum on our recent gas/fuel test, a technical tip, and we also will mention an enthusiast who is truly dedicated to the Pontiac hobby. A later column will discuss an NHRA approved method of installing a master disconnect switch to immediately stop the engine when a master switch is operated. If you need such  information immediately contact me.

Concerning our test of race fuel versus pump fuel in the February, 1997, issue, we have additional information on the subject. You may remember that John Mino obtained a significant improvement on performance of his Pontiac when he used 100 octane fuel at the drag-strip, yet our tests showed little or no improvement. I use Amoco “Clear” 92 octane pump gas and it apparently is one of the best performing 92 octane pump fuels wherever it is sold. Additionally, our local station is a high volume unit, so the gas is relatively fresh. Thus, I conducted the test using some of the best and the freshest pump gases available anywhere. You may not have access to equivalent quality pump gas, so race fuel may well provide a performance gain for you, as it did for John. For maximum performance, you should try all the available premium brands of gas in your area. Then determine whether or not race fuel would help, test it against the best pump gas available.

Take a moment and turn to the list of Technical Advisors inside the front cover of Smoke Signals magazine. Look at “Can Am 1977” and you will see Verne Howard’s name. Now look inside the back cover at the list of POCI Directors and you will see Verne’s name again under the Midwest Division. Those of you that attended the Nationals in 1990 in Kansas City, will recall Verne working almost fulltime (along with many other local volunteers) in support of the convention. As of 1997, he has attended three of the Nationals, since 1990 with two of his Can Ams and has assisted with judging and other technical aspects. In addition, Verne has been President of a local non-affiliated Pontiac Club consisting of 50 to 60 members for almost 10 years.

His Can Ams are not only competitive at the shows, but he regularly drag races one of them. He won the 14 to 15.99 second class at the Cordova Sunday race following the 1996 Nationals, won a street car race at the Kansas City track this past summer, and finally, he won the Ram Air Class at the 7th Annual Pontiac Uprising at Arkansas City, Kansas, in October 1996. This with a car he drives to and from the events. The Can Am that he races has received a normal stock type engine overhaul including carb and HEI distributor tune-up. The worn original cam was replaced with a Pontiac 067 unit which is very close to the specifications of the original Can Am cam. Otherwise, the drive train is in stock condition. This very heavy car has run as quick as 14.80 at 91 mph on street tires through a stock exhaust (Ram Air manifolds and Super Dynomax mufflers). It again proves how quick the stock Pontiacs really are with minimum add on parts, but with careful and detailed tuning. Although Verne does not have the time to practice at the strip regularly, he has developed a consistent driving technique and maintains his car to run very consistently. The result is a car-driver combination that is competitive in any non-electronic class of actual driveable vehicles.

There are many more people like Verne throughout the country that have helped all of us with their support and input to our hobby and we thank them. As I have had the privilege of associating directly with Verne during these past 10 years, I have witnessed the effort he regularly expends on anyone interested in Pontiacs as well as the clubs. I can vouch that he is a true friend to all Pontiac people. I congratulate him for his efforts and accomplishments.

Technical Tip.

Cam Decreeing

When installing and degreeing the camshaft, we often find we need to shift the initial overall cam timing by several degrees to obtain our desired setting. The 4 degree advance and retard key ways on our after-market timing sets provide a coarse adjustment, but generally are not as accurate as we would like them to be. The aftermarket offset cam keys are normally rated at 2 and 4 degrees, but sometimes very considerably from their rating. Most engines will not respond to an error of plus or minus 1 degree, but any more variation than 1 degree may often have an effect on engine performance. Additionally, remember that a 2 degree shift of the cam actually results in a 4 degree shift of the crank. Therefore, a 4 degree cam change is a whopping 8 degree overall change and that amount will ruin the performance of any cam that is reasonably correct for the application.

Chris Wismer of Bethlehem, PA, advised that Mopar sells a set of five offset keys that fit our Pontiacs. The set sells for $25.00 list price. The part number is P42886500 and the package includes one each of 1, 2, 3, 4, and 5 cam degree keys. They are very accurate and provide tremendous flexibility when installing the cam at very close specifications. The Mopar set is not listed in the normal dealer parts book, but is in the High Performance catalog at any Mopar dealer.

A quick method of determining the offset amount of a cam key is to physically measure it. A standard cam key measures a nominal .187 inches wide. The circumference of the cam nose is 3.526 inches and that dimension divided by 360 degrees equals .0098 inches per degree offset. Accordingly, a 2 degree advance key would measure a total width of .187 + (2 x .0098) = .207. Although it is hard to obtain extremely accurate physical measurements, this method sure beats the trial and error of installing the key and rotating the engine only to determine what you thought was a 2 degree key really was a 3.5.

One last comment on cam installation. A normally worn timing chain does not retard the timing as much as most think,unless the chain is stretched so much it is about to fall off the gears. Surely any reader with a performance engine would never allow a chain to become that loose. A deliberate advancing of the cam by 2 or more degrees in anticipation of chain stretch will result in poor performance on a correctly selected cam. We suggest that all cams be installed as recommended by the cam shaft maker to plus or minus one degree in order to obtain performance immediately and that timing chains be treated and replaced as any other wear item on the engine. None of this paragraph applies to planned advancing or retarding the cam in order to deliberately modify the engine performance. Thanks again to Chris Wismer for his advice on the Mopar keys.

Request for information from the reader

I am interested in the experiences from any reader that has installed Edelbrock 87cc aluminum heads (without a host of other changes) in place of a comparable CR cast iron heads that were in good condition. In other words, I would like to know what actual performance changes, if any, both on the road and at the drag strip are caused by the aluminum heads alone as compared to similar compression iron heads in good condition. I am not interested in switches to the heads in conjunction with other changes that change the compression from 8 to 10, add 4 tube headers in place of stock manifolds, replace a stock cam with some big roller, replaces junk heads that should have been pitched five years ago, porting or other changes to make the heads more like Pontiac units, and/or modifications to the engine to run to a 5800-6000 RPM shift point rather than the stock 5000-5400. Obviously, those kind of changes should boost performance, even with bone stock heads. If you have direct experience with such a change, please contact me through this magazine or direct. I have no plans to publish such information. If enough feedback is received, I would consider mentioning it in this magazine. Also, I am not asking for your experiences with the new heads in race applications, because I am certain they are quite successful when correctly prepared.

I would suggest however, that readers considering purchase of these heads for streetable vehicles use readily available pump gas to determine how much performance the heads alone will provide as compared to what they are now running. If you are told that bigger cams, higher RPM, etc. is/are required with the aluminum heads, beware. If the seller says the new heads need to be ported, beware. Similar performance enhancing changes can be made to your present heads and engine for much less than the total cost of your aluminum heads. “Superior” heads should improve performance with your existing equipment or they simply are not superior! If you are advised that you must (or should) incorporate the above noted changes along with the aluminum heads, you may want to consider paying a qualified person $1,000.00 (or less) to correctly port and prepare your iron heads and bank the remaining $1,500.00 you saved. Remember that any performance gained due to the lighter weight will likely be lost due to the very poor heat retention (thermal efficiency) of the aluminum heads. Also note that we continue to run low 12’s – 110-112 at 4100# race weight with correctly prepared 1971 #96 iron heads with 88.5cc chambers in a very streetable 462 powered vehicle on 92 octane pump gas. Ask the sellers if the new aluminum units will provide the level of performance for you that my “obsolete” iron #96 heads do for me! Any and all feedback on this subject of 87cc aluminum heads replacing decent iron heads on actual driveable vehicles will be sincerely appreciated.