Holland Hornet Glow Head Thread

[EXModelEngines]

Does anyone know the specification of the glow head thread for the Holland Hornet 049 / 051 engine?

Thanks!

[Kim]

I could try to measure the adapter I have for mine if no one else has them. Also, the engine is down right now, so I could mail the adapter to you if that would help.

Hornet Killer Kim

[EXModelEngines]

I could try to measure the adapter I have for mine if no one else has them.  Also, the engine is down right now, so I could mail the adapter to you if that would help.

Hornet Killer Kim

Thanks Kim - a measurement would be appreciated! The Cox one is a little wacky (17/32-40), not sure if this type will be the same.

[Kim]

Oh man...I'd screw it up! Let me just mail it to you! I could have it on the way by tomorrow morning!

[EXModelEngines]

Oh man...I'd screw it up!  Let me just mail it to you!  I could have it on the way by tomorrow morning!

Fair enough - thanks!

[Kim]

Oh man...I'd screw it up!  Let me just mail it to you!  I could have it on the way by tomorrow morning!

Fair enough - thanks!

COOL BEANS!!! I got it packed...please P.M. me your snail mail !!!!

[Kim]

Yo! I just found the original burned-out head, along with some gaskets (just KNEW I kept that sucker!).

Would that work better? I can send both.

[EXModelEngines]

Sure - sounds good.

[F4D Phantom II]

Hello Ex
                      Doug galbreath make a head that uses the nelson plug.here is a pic and link.
                                                                                                                                     Juan
http://www.the-printer.net/DookCat.html

[ffkiwi]

I think you'll find the important word here is 'made' not 'makes'.....Doug G is well into his 80s and not making much at all these days-not surprising given his age (and no doubt failing eyesight and other possible health issues play a part)-after all virtually all his aftermarket stuff-whether it be accessories or engine rework-requires precision machine work

Matt-I have a couple of his adapter heads-are you wanting the details or is it original HH glowheads you're after dimension for?

ChrisM
'ffkiwi'

[EXModelEngines]

I think you'll find the important word here is 'made' not 'makes'.....Doug G is well into his 80s and not making much at all these days-not surprising given his age (and no doubt failing eyesight and other possible health issues play a part)-after all virtually all his aftermarket stuff-whether it be accessories or engine rework-requires  precision machine work

Matt-I have a couple of his adapter heads-are you wanting the details or is it original HH glowheads you're after dimension for?

ChrisM
'ffkiwi'

Yes, unfortunately, I do not believe Doug G is doing any machine work.

I was able to get a sample from Kim of the original and adapter. While the chamber shapes are different I think I should be able to design a model of either the original head or an adapter if going that route. Right now I am trying to figure out the exact thread size. Measuring, it looks like a 9/16", but not sure if it is 32, 36, or 40 threads per inch. Its hard to measure given the small threaded area. If you knew the thread specification that would be very helpful. My backup plan is to purchase a few taps!

Matt

[fredvon4]

Hey Matt it is Friday after 0700 pacific   wait a few hours then call Doug...when ever I chatted with him I had a hard time getting off the phone
he made heads for what you seek to know

2840 Prado Lane, Davis, CA 95618
Tel. 530-400-3562 cell
F1Cdoug@aol.com

[ffkiwi]

Matt-looking at a mint original under magnification beside a mint Cox head-I am of the opinion they are the same thread pitch-ie 40 tpi-but obviously the HH is a larger diameter than the Cox-so my guesstimate is a 9/16"x 40 thread...

ChrisM
'ffkiwi'

[EXModelEngines]

Matt-looking at a mint original under magnification beside a mint Cox head-I am of the opinion they are the same thread pitch-ie 40 tpi-but obviously the HH is a larger diameter than the Cox-so my guesstimate is a 9/16"x 40 thread...

ChrisM
'ffkiwi'

Thanks for taking the time on this. I think I have a 9/16-40 tap so will give it a try with the sample Kim was so generous to provide.

My early thinking on this is to model the chamber shape and overall style to that of a Tee Dee head. An extra fin should also assist with cooling.

[ffkiwi]

Matt-an afterthought that might impact your plans-there were two distinct HH heads made-the normal one-and the so-called 'hot head' .....I don't know what the actual differences were-but I assume they would have been similar to the difference between the std cox head and a TD head-in terms of head shape and compression....this might impact what shape you decide to give your adaptors...?

I will check my two Hornets plus my stock of spare heads to see if I have-by sheer chance examples of both types.....all my spares are the same type-but one of the two heads on the respective engines is different to all the others....

ChrisM
'ffkiwi'

[Sponsored content]