British Anzani A & B Stock & Alky Racing Engines

[John (Taylor) Gabrowski]

Harrison race products also included making parts and equipment that would fit British Anzanis. In fact Harrison produced a variety of light weight spring loaded exhausts for Alky that took off a lot of the heavy loading conventional steel pipes added to the overhanging cast iron engine block would then break the mounting flange on the crankcase to torque tube/tower aluminum mount. This was a cheaper alternative. Loose the odd pipe to spring failure or have the whole engine block shear off at the mounting neck and do what?

There is still a lot of pro-con concerning steel versus aluminum megaphone tipped exhausts systems. I wish a knowledgable writer on that subject would give that a go for people like me that remain quite confused when they hear that steel is better than aluminum? Anyone??

[smittythewelder]

Is a cast aluminum pipe really any lighter than the same pipe made of 20ga sheet steel?

[John (Taylor) Gabrowski]

When you compare the Harrison aluminum elbo, megaphone stack castings and its mounting spring steel 2 springs to hold the setup together against an Anzani hand made welded megaphone, its steel elbo, steel flange to cast iron block plate, all welded together, add more brazing to help shape the change of opening from square to round at the elbo and flange plate and then you add the stack strut system to support each one and then bolt up a good steel or thick aluminum mounting system under the middle head studs to hold/support and encircle (the stack struts) and complete stacks, that whole system is one lot heavier. I am not sure if the Harrison's required a wrap around or top rod stabilizing clamping from the front of the crankcase ( the Anzani rods start off the magneto mounts) to plates across head bolts to have these rods run though, threaded at the end to spread the load from those steel overhanging and struted stacks (and cast iron loop block). If the Harrison didn't, that was extra weight taken off there too? I wished I had more of the Harrison elbos, the ones I had were pretty damaged (rather ugly re-melted) from Bill Tenney's garage fire years ago and un-usable, but you could see the weight saving non the less. As you can see, I have 4 aluminum Harrison pipes for different tunning applications but no elbos.

The other point I am seeking is some input why some Alky owner/preparer/drivers prefered steel over aluminum stacks to do tuning and power development? Steel contributed more resonance, harmonics or something that aluminum can't or won't as there are so many different steels and aluminums too??? Smitty or anyone else?

[smittythewelder]

Okay. You know a lot of physics (and you don't need to know much for this); think about thermodynamics/heat-transfer and acoustics . . . .

[John (Taylor) Gabrowski]

The exhaust roar from a square exhaust ported 2 cylinder like that is sure unique but I always thought it was the nitro loading in the methanol had more to do with the horsepower that those pipes.

Some humor - Acoustic means? A stick Newfies chase cooos with for morning milking in Newfoundland!

[John (Taylor) Gabrowski]

Okay. You know a lot of physics (and you don't need to know much for this); think about thermodynamics/heat-transfer and acoustics . . . .

I kind of scratched my head for a moment, you mentioned those. I took out the Lazer 128 old note book IBM compatible from many years ago that has some modern pipe formulas in its hard drive and poked around the B-Anzani Alky there and plugged some figures in and tossed that around 3 different ways. Use those results with nitromethane loaded in methanol base and lube to the extent they used to at 20% to 40%, something would have to give way with a bang! A good racing engine is only as good as it can last the distance and do so reliably for a reasonable period of time (in some years) so to get there, there seems little doubt some compromising is required or your engines life is so extreme it has no virtual life at all when it could do way better than that. The minute you think away from megaphones to tuned expansion chambers, you pretty much write a new chapter to your engine book that also inlcludes a quieter engine! No! No! We can't have that!! LOL!

[John (Taylor) Gabrowski]

How hot did that fire at Bill Tenney's garage not far from his home at the lake front get?? Those pictures are for tommorows posts. I will have a followup post on some Anzani porting theories that were tried but what they were trying out and for what effect is lost on me but perhaps some other readers with some background on these engines will recognize what those weird "holes" added to the cast iron block were all about?

[John (Taylor) Gabrowski]

The following pictures are going to be interesting from many perspectives of just what the late and great Bill Tenney and his crew were thinking? and doing to A and B Anzani Alky blocks. They ran them as well with the strange modifications but it seems to be halted with the garage fire back in that era. Have a good look and help me stop scratching my head?

[John (Taylor) Gabrowski]

Does anyone know why they would drill ports right through a cast iron block right through to the cylinders? This A - Alky was run with those extra dual ports per cylinder next to the exhaust ports, but how did they act??

[John (Taylor) Gabrowski]

When they broke the mounting flange on a castiron block right through to the cylinder, they did not toss the block, they fixed it right into the cylinder. That seemed very important to that experimental added ports project, so nothing was tossed. They modified and kept right on testing. The barzing becoming part of the bore where it was not critical to the rings was quite alright.