Wednesday, January 02, 2008

SCX Vintage BRM F1 - Review

Vintage F1 slot racing takes you back to the way we used to do it in the 1960's, when our rules allowed nearly anything, as long as the wheels were open. Of course, traction magnets had not yet been invented; and so, this SCX car has no magnet. SCX has revived the BRM P261, with vintage RX motor. The BRM P261 poses beside its predecessor, a vac-body P578 (driven to a word championship by Graham Hill in 1962). The SCX car was raced 1964-1965, under F1 rules requiring 1.5L engines; its V-8 produced 200+ HP.

Graham Hill is in command, with his helmet marked for the London Rowing Club; the white arrows are oar blades. Graham has the motor whirring in his belly. The motor bearing is surrounded by a white felt pad, intended to hold a reserve of oil against the Oilite. This is the way it was done, when motors usually lived in HO/OO locomotives, and were oiled once a year, if that.

The V-8 engine has 16 inlet stacks. In reality, this model of BRM should have only four per side (the upper row), and only two exhaust stacks (the ones on top of the engine). Suspension detail is heavy; but, in my opinion, the car's virtues outweigh its faults.

Here is a view of the venerable inline, open frame, single magnet motor. The SCX RX motor is a direct descendant of the Triang motor used in Scalextric cars in the 1960's, including the stub brackets which anchor the motor into the clamshell body at the gear end. Downforce from the block magnet measures only 5 grams on a Magnet Marshall; the tach reads 19,500 RPM on 12 volts. But look out for that wide track, caused by over-long axles front and rear:

Trimming the ends of the axles at least .1" on each side (2.5mm) brought the wheels closer in to the suspension; the narrower track increased cornering speed:

Fresh out of the box, the BRM turned a 6.766 second best lap on my 61 foot wood track, at 13.6 volts. Sanding the wheels concentric, and remounting the tires more carefully, resulted in the best time improved to 6.669. Sanding the tires true reduced time to 6.212. Narrowing the track reduced time further, to 6.125. Almost ready to take on the Ninco NC-1 crowd! Still more tire truing brought time to 5.984; finally a contender. The SCX BRM handles smoothly and predictably, with no problems after the wheels and tires are trued. The gears mesh smoothly, there is no excessive rear axle play; overall weight, and weight distribution seems good. The car is fun to drive, and presents a good argument for low-power, no-magnet racing, at less than insane speeds.

Now, if you want this car to go faster, I can tell you it does go faster with Slot.It 15x8mm wheels (5.876 sec), and stock tires. With 8mm wide Super Tires, 5.562. Still no handling vices! What a car. No hop, very smooth, and faster than Scalextric 1.5L F1 cars (Ferrari and Cooper). The motor can be tuned to rev about 1,000 RPM faster by bending the hairpin brush spring to exert more pressure; this gained a slight increase in track speed, to 5.551. Meanwhile, here is a link to a good reference site on BRM F1 cars:
http://members.madasafish.com/~d_hodgkinson/brm-P261.htm

Thanks to SCX for the review sample car.

3 comments:

Anonymous said...

..could this be the BRM 3 liter H16 engine which would make this car a P83 0r P115 0f later vintage.....still mins a nice runner.....although MRRC's old version looks just as good with a V8

Robert Livingston said...

I looked into the H16, and it was not used in this body style, particularly with Graham Hill driving, and the number 3. Nor did the H16 have valve covers and exhaust manifolds as on the model. The slot car is a composite, typical of toys from days gone by, combining features of several cars. Overall, it is closest to the BRM P261.

Dave said...

I still like the looks of that car though. Reminds me of the old formula one's from my youth. I think the driver's name was Jim Clark? Is that correct?

Dave