Author Topic: Len Mason's "Mastiff" - chewed from the solid  (Read 34768 times)

Offline Brian Rupnow

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Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #225 on: October 26, 2018, 02:30:22 PM »
Congratulations Deltango. Very nice engine.---Brian

Offline Roger B

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Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #226 on: October 26, 2018, 05:28:06 PM »
Splendid  :praise2:  :praise2: Perseverance pays off  :)  :) Now for the twin carb version  :stir:
Best regards

Roger

Online Art K

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Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #227 on: October 26, 2018, 08:48:11 PM »
David,
it's great to hear that flat 4 pure along. Great job!
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Dave Otto

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Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #228 on: October 26, 2018, 11:09:54 PM »
Congrats on the first pops David, you have done a splendid job on this little beauty!

Dave

Offline Kim

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Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #229 on: October 27, 2018, 12:48:24 AM »
That is very exciting, David!  Great to see it running  :ThumbsUp:
Kim

Offline Dave Otto

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Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #230 on: October 27, 2018, 12:56:29 AM »
Hi David

For the assembly to be opened in Alibre you will need to create a package file that will contain all the parts of the assembly.

Thanks,
Dave

Offline deltatango

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Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #231 on: October 27, 2018, 02:01:02 AM »
Thanks for that reminder Dave! I'm so used to just clicking on the assembly file that I forgot that it needs all the components to access.  Sorry to everyone who downloaded the .AD_ASM file on its own. Here is a link to a zipped up complete directory with all the files:

Link removed 23/11/2018 DT

and another to the 3D .pdf:

Link removed 23/11/2018 DT - the links have been up long enough for those who are interested to do the downloads. If anyone else wants the files please send a PM.

Many thanks to everyone who has passed on their congratulations, support is very important.

I've already made two carbies and I think these are probably necessary for Mastiff to run really well. The very long inlet tract and small bore may be why the engine doesn't rev up as well as I hoped. I now have to make and rig up the linkages and try again.

Regards to all, David
« Last Edit: November 23, 2018, 02:19:35 AM by deltatango »

Offline Admiral_dk

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Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #232 on: October 27, 2018, 04:32:54 PM »
Nice runner  :ThumbsUp: congratulations  :cheers:

Thank you for the files  :praise2:

Offline deltatango

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Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #233 on: October 28, 2018, 04:58:35 AM »
Thomas asked for a longer video so here it is:


and a couple of stills:





The engine is improving each time I run it, it will almost idle now.

When it is pulled down for a clean out I'll replace the "oiled paper" gaskets recommended by Len Mason with Hallite and Klingersil, right now Mastiff piddles oil like a 1960s British 'bike. There is a lot of misfiring happening and the spark plugs are very dirty, some of this is oil but a lot is just black carbon from what seems like very rich running. Closing the main jet down with the needle doesn't seem to have much effect, until the engine stops.

Regards, David

Online Ye-Ole Steam Dude

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Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #234 on: October 28, 2018, 08:19:56 AM »
Hello again David,

Thanks for the longer video. You have to be very satisfied with the looks and performance.

Have a great day,
Thomas

Offline gbritnell

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Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #235 on: October 28, 2018, 10:53:10 AM »
HI David,
The main jet adjustment is primarily for high speed operation and won't affect the idle running until like you say it then stalls. I will look at the drawing this afternoon and see if I can give you more information on what needs to be done.
gbritnell
Talent unshared is talent wasted.

Offline 90LX_Notch

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Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #236 on: October 28, 2018, 02:32:21 PM »
Congratulations David.  This has been a great build.

-Bob
Proud Member of MEM

My Engine Videos on YouTube-
http://www.youtube.com/user/Notch90usa/videos

Offline Craig DeShong

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Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #237 on: October 29, 2018, 12:50:38 AM »
Fantastic David.  Job well done!   :cheers:
Craig

Offline 10KPete

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Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #238 on: October 29, 2018, 02:29:56 AM »
That is a very attractive engine from many standpoints. With George on your team there is no doubt you have it purring like a kitten.

 :ThumbsUp: :popcorn:

Pete
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SB 10K lathe, Benchmaster mill. And stuff.

Offline deltatango

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Re: Len Mason's "Mastiff" - chewed from the solid
« Reply #239 on: November 19, 2018, 08:12:44 AM »
Thanks to everyone for the words of encouragement!

A few things have happened to Mastiff since I last posted and, apart from a persistent slight roughness (miss-fire ?) it now runs well:


The laser tacho shows it idles at about 1100 RPM with the throttle close to, or fully, closed and the idle screw has some effect on this. The engine revs out to ~4500 but I'm not game to let it stay there for very long, particularly without a load. The cooling hopper is hanging off the end of the test stand and needs to be re-made but this leaves enough space at the flywheel end to couple up a load (generator?).

The changes were to both the ignition timing and the carburetor. I'd managed to make the same two errors to both carbies; first the main jets were over size at ~ #68 (they are now #70 as drawn) and I'd used fibre washers for sealing the fuel banjo rather than the (rather vaguely) specified "paper washers". The effect of this was to pull the main jet downwards out of the throttle body by most of a mm. This was easily fixed (once recognised!) and had a significant impact. Making new jets cost me a couple of drills but I've learned something of how to handle those from the exercise.

An ignition timing problem caused a lot of head-scratching before solution - the super-glue fixing the distributor rotor-arm to it's metal core had failed (but the fit was tight) and the sparks slowly got further and further away from when they should have been until the engine wouldn't run. One day it was a bit reluctant to start, the next day no-go at all. The pattern of spark damage on the face of the rotor arm gave this one away.

The most important other change was replacing the M3.5 cap screws on the cylinder heads with M4.0 studs. All the dismantling and reassembly damaged the threads in the blocks (entirely predictable with hind-sight) and the heads weren't secure enough anymore.

Its now time to get on with some workshop re-organisation and then make a start on the Wyvern (castings to fondle first this time). I'll probably run a build log on this one as well.

Thanks to all Forum members for the advice and the encouragement throughout this long series of "learning opportunities"! I'm very pleased to have found MEM and that I joined in.

Regards to all, David