Author Topic: Build of Cirrus V8 (C Fellows design)  (Read 26097 times)

Offline Johnmcc69

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Re: Build of Cirrus V8 (C Fellows design)
« Reply #105 on: June 07, 2014, 11:52:40 PM »
Flywheel looks great Simon! Did you get the cam tube worked out?

 Is it running??

 John

Online sco

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Re: Build of Cirrus V8 (C Fellows design)
« Reply #106 on: June 08, 2014, 06:54:50 PM »
Hi John,

Got the cam tube re-made properly but talking to Chuck think we identified a mistake in the drawings / cad model - the cylinder admission hole is offset from the cylinder centre line with the intention of increasing the spacing between holes in the camshaft.  However in the cad model the offset is the wrong way round so moves the holes closer together instead.

Fitted the flywheel today - still needs some tweaking but it is starting to run better;

<a href="http://www.youtube.com/watch?v=D9vXyHCwUvw" target="_blank">http://www.youtube.com/watch?v=D9vXyHCwUvw</a>

Simon
Ars longa, vita brevis.

Offline Don1966

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Re: Build of Cirrus V8 (C Fellows design)
« Reply #107 on: June 08, 2014, 07:18:23 PM »
She runs and sounds great Simon and the flywheel is a treat great job.


 :popcorn:
Don

Offline fumopuc

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Re: Build of Cirrus V8 (C Fellows design)
« Reply #108 on: June 08, 2014, 07:22:36 PM »
Yes, Don is absolutely right, that is a great sound. Nicely done.
Kind Regards
Achim

Offline Johnmcc69

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Re: Build of Cirrus V8 (C Fellows design)
« Reply #109 on: June 08, 2014, 07:23:38 PM »
 :facepalm2:
 I'll have to look at the models. Looks like drawing revision #1 is due. Please let me know if there any other changes to be made, I still remember I need to increase the oil pan wall at the front & back...

 I'll have a look & send revised drawings to you & Chuck to see if I get it right.  :killcomputer:

 It does sound good when you rev it up though...

 John

Online sco

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Re: Build of Cirrus V8 (C Fellows design)
« Reply #110 on: June 08, 2014, 07:38:14 PM »
It was the sound of Chucks model that made my mind up to build one for myself  ;)

It's also not consistently 'firing' yet on all cylinders as a couple of the ball valves keep sticking.

Simon.
Ars longa, vita brevis.

Offline cfellows

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Re: Build of Cirrus V8 (C Fellows design)
« Reply #111 on: June 09, 2014, 12:12:51 AM »
That does sound good, Simon.  Sounds like it has a full race cam in it.  The "misfires" make it sound more like a real racing engine which does fire irregularly, particularly at idle.

Chuck
So many projects, so little time...

Offline Tennessee Whiskey

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Re: Build of Cirrus V8 (C Fellows design)
« Reply #112 on: June 09, 2014, 12:26:34 AM »
Simon, wot Chuck said  :ThumbsUp:. It's hard to believe that sound is coming from an air driven engine, sounds just like an I/C.

Whiskey

Offline cfellows

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Re: Build of Cirrus V8 (C Fellows design)
« Reply #113 on: June 09, 2014, 04:16:49 PM »
Simon, You've probably already figured this out, but if you hold your finger close to the exhausts, you can tell which cylinders are firing regularly and which might be "misfiring".

Chuck
So many projects, so little time...

Online sco

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Re: Build of Cirrus V8 (C Fellows design)
« Reply #114 on: June 09, 2014, 05:32:15 PM »
Yeah been doing that plus poking a hex key up the exhaust pipe to see whether the ball is stuck open or closed.

One slightly disappointing aspect is that the engine doesn't freewheel very much - when you shut the throttle ;-) (release the trigger on the blow-gun) - it stops almost instantaneously.  Not sure if this is because of the valves sticking or an indication that it doesn't breathe very well due to the small cylinder admission hole.

Simon.
Ars longa, vita brevis.

Offline gbritnell

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Re: Build of Cirrus V8 (C Fellows design)
« Reply #115 on: June 09, 2014, 06:14:51 PM »
Hi Simon,
Great sounding engine!
gbritnell
Talent unshared is talent wasted.

Offline cfellows

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Re: Build of Cirrus V8 (C Fellows design)
« Reply #116 on: June 10, 2014, 06:10:10 AM »
One or more stuck balls will keep the engine from freewheeling.  It doesn't hurt anything to make the exhaust passage several thousandths larger than the ball.  Also, any metal bits that get in there will also cause the balls to stick.

Chuck
So many projects, so little time...

Offline Roger B

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Re: Build of Cirrus V8 (C Fellows design)
« Reply #117 on: June 19, 2014, 06:56:26 PM »
Only just found the video. looks and sounds great Simon  :praise2:  :praise2: As the others have said you would not think that it is an air engine. To steal from another thread, more in the angry top fueler  direction  :ThumbsUp:  :ThumbsUp:
Best regards

Roger