hilleyja

My Feedback: (3)

I'm putting together a Great Plains Viper and mounting a stock Webra Speed 40 on the nose with a 9x6 APC prop. Am I kosher for AMA 424 racing?

Any experience out there with the Webra Speed 40 for pylon racing?

Ed Smith

To race AMA424 strictly to the AMA rule book the engine rule is the rule to take note of. Any engine is allowed but if it can turn a stock 9.0 x 6.0 APC prop at over 16.5000 rpm it is not allowed. The viper airframe is legal. There are endless groups all flying their own version of 424 on a regional basis. It would be wise to check what is being flown in the area in which you intend to race.

Pylon Racing rules can be downloaded from the AMA website.

Ed S

hilleyja

My Feedback: (3)

Yes, I am aware of all that. I have also reviewed the AMA rules on 424. They leave a lot up to the local club. I have submitted my configuration to the Flying Hillbillies in West Virginia -- they are the group I will probably compete with a few times this season. The reason for my question above is 2-fold.

1) The original price on the Webra Speed 40 at J&C Hobbies was $109.00 -- I paid 10% less than that. AMA recommends that the owner be agreeable to give up their engine for $100 if another pilot request to purchase it -- I have no problems with that since I paid less than $100 for it.

2) I'm not familiar with the capabilities of this engine. Can it spin up a 9.0 x 6.0 APC at over 16,500? I have a Webra Silverline 40 and am sure it can't do that. I looked up the manufacturer stats on the engine and found there are 2 Speed 40s. One is the the Sport, the other the GT. I'm at work so don't know which one I have. In any case, the max rpm for the GT is listed as 16000rpm.

Ed Smith

Well then, why did you ask??

Ed s

hilleyja

My Feedback: (3)

What, you only look at part of the post and then dump on the poster? I'm looking for support/input from someone familiar with interpretations of AMA's 424 rules and also familiar with the use of the Webra Speed 40 in 424 pylon racing. If you have no constructive input please don't respond.

Ed Smith

You asked a legitimate question. I mistakenly took the trouble to provide you with an answer. Then you say you knew it all.


GOOD! you are on your own!

Ed S

hilleyja

My Feedback: (3)

What answer? You told me to check out AMA's 424 rules. I told you I already did that. Though I appreciate your bringing the AMA rules to my attention, I was already familiar with them -- if you had no other constructive input beyond that why did you persist in your confrontational post? Did the following quote somehow get missplaced on your screen -- where do you infer from that I was saying I new it all? In case you didn't fully read my post, the highlighted portion of the following quote clearly clarifies my original question and was entered as a result of your post, i.e. Again, I am already familiar with the documented AMA rules. I'm looking for interpretations of them.

daven

My Feedback: (1)

From what I see, Jim knew what the rules said, but just wanted to make sure he was interpretating them correctly. He is also still wondering about the Webra .40 and its capabilities with the mandated props.

I know my Webra Blackhead .40 can't hardly get out of its own way, but I am not familiar with the speed version.

Lets keep this on track please.

ALbert.S

We raced the Webra and the Rossi for many years.What I can remember is the Webra will have much higher RPM's than the Rossi but will use a smaller pitch prop.What you will have to do to make it legal, if the club is following AMA rules,is check the muffler opening.The stock mufflers that come with the Webra probably have outlets that exceed the max allowed.So make a plug to bring the outlet down to the proper size.Then put on a 9/6 the kind the club has for its standard and see what it turns 16,500 I think is max allowed. There were two carbs that were used also.As I recall the one with all the slides and stuff didn't work to well.The one that looks like a OS sort of was the one that worked the best. Webra sold a muffler hole reducer but I don't remember what the size was It cut down the hole to build up some tank pressure.With the big outlet the engine dosen't draw fuel very well.You have to get the tank as close to the engine as possible or you will have sagging in the turns.If this is sounding kind of negative I'm sorry but I think that the Rossi with it's lower RPM and better power won most of our races.I hope this will answer soome of your questions
AL

daven

My Feedback: (1)

If backpressure is an issue, you may want to install a 4oz Tetra Bladder tank. Although not technically pressurized, they do help immensly in this area.