frewster

iTrader: (1)

Alpha made Argus. They did not make Arrow. Atom originally came from Go but I'm not sure who's making the SV-1 now that Go has been gone for years. Probably Alpha. Remember that just because Alpha or Nova or OS makes an engine for someone it doesn't mean it has the same parts as their own designs.

Alpha makes their own engines. OS is in no way connected to Alpha.

s10096898

Will the Ryan Lutz Cooling Head(Pink colour) fit on a Alpha Dragon 2?

UrabusDenis

Yes, they are all interchangeable

s10096898

Are the crankshaft, piston, rod and sleeve interchangeable too?

UrabusDenis

The rods are all the same, there was a small running change to the material sometime when the pink head Lutz engine came out, but the dimensions stayed the same. I've been running Alpha engines since the A852 so I can confirm they are the same since that one.

The crankshafts should all be interchangeable as well, but you will be changing the engine performance with that change. With the piston and sleeve I'm not 100% sure, they should fit but again it will be a change. If you have a specific question about parts interchangeability, feel free to ask here or send me a PM

You can check the exploded views here and check what you need by comparing the part numbers
ALPHA PLUS MODEL CO., LTD.

jersey

iTrader: (1)

UrabusDenis

Yes, the D3 rod is a bit beefier but the hole dimensions and the distance between them is the same

frewster

iTrader: (1)

Broke in my mystery Alpha today. It started right up on the first try and break in was easy. Running it on 25% nitro right now.

But I have a big problem. Idle gap is set and the needles are a little rich but pretty close to tuned. If I keep the throttle below 1/2 everything is normal. But if I get to or above 1/2 throttle for a second or two it won't go back to idle when I let go. It'll stay revved up for up to 5 seconds even though the carb is closed.

This has to be an air leak, right???? I replaced all of the fuel line and tightened the pinch bolt and HSN housing. Does anyone have any idea what could be going on? I've never had an engine do this. The fuel and glow plug are both new. I made sure the head and backplate are tight.

Any help is appreciated!!!

UrabusDenis

Does the carb return to closed? Like, do you see it with the engine not running, without the filter? I always have a rubber band to close the carb, they and the throttle linkage gap have to be matched.

frewster

iTrader: (1)

Yes. I made sure that the linkages and trim were properly set. At neutral the carb return spring and the spring on the throttle linkage are firmly keeping the carb closed. There is a small gap between the servo horn and the stop on the throttle linkage that it pulls. I made certain that it is completely closed at neutral/idle.

When I removed the air filter to set the idle gap I pushed on the slide to see if it was completely closed at neutral. It is. I've been running nitro for 10 years now so I usually know what I'm doing but this has me stumped. I feel like it must be an air leak.

UrabusDenis

Very weird. Sounds like you know what you're doing, possibly it could be an air leak. Maybe try your luck in the Trackstar thread, maybe someone had a similar experience (since it isn't an Alpha). And keep us posted, I'm interested to hear what went wrong

frewster

iTrader: (1)

I'm confident it's an Alpha. Carb is identical to the Alpha carb I put on my Go/Trackstar .21 and the crankcase is identical to an Alpha only design. I've got some Lucky 7 sealant from Absolute on the way. I'll figure it out. Thanks for trying to help!

frewster

iTrader: (1)

Well, I got some Lucky 7 style engine sealant from Absolute Hobbies and sealed around the HSN, carb, and backplate. I gave it a while to cure and fired it up to see if anything has changed. Nothing improved... it's the same as before. This time I took some video. Towards the end you can see how it really runs away when it's revved up and I let off the throttle. It's running sloppy rich on the HSN and LSN and I richen the LSN a few times in the video but it doesn't help. I'm stumped. It's a good thing I've got a couple other engines that don't have problems for racing this weekend.

Any ideas?

iplaygames

to me, sounds like the idle is high and the HSN is lean.. you also need to sort out that throttle linkage to be straighter.
also that engine, the XACT, go built, but that one looks to have an alpha carb...
Can you show more photos of it.

frewster

iTrader: (1)

I posted pictures earlier in the thread. That's not the original head. You can see the one it came with in those pictures. I'll try richening the HSN. Why do you think the idle is high? You can see how it idles fine when it isn't running away and I have checked the idle gap with the insert out and it is less than 1mm. I'll straighten out the linkage as well.

If none of that works I guess I will take the carb apart to see if anything looks wrong and to seal it.