Hand starting the Holt model engine

[kingdl72]

Amazing work sir! The sound on idle is very nice too

[themadmailler]

awesome!! at an idle it even sounds like the big Holt engines! (sort of, anyway)

[Manorfarmdenton]

Superb!

[richardarichter123]

what was the holt engine used for cars farm equipment tractors

[triggerdance]

thats just beautiful!!!! i have tears in my eyes listening to that thing run! does it ever fire out the carb? does it have any back pressure?

[gbritnell]

@triggerdance

I have never had it backfire. The cam timing is mild and the ignition timing is about 15 degrees BTDC so I've never had it spit back. I'm not quite sure what what you mean by back pressure? Do you mean crankcase pressure? If so I do have a vent on one of the access covers but with the configuration of the crank, 2 up, 2 down, it kind of equalizes itself.

[triggerdance]

@gbritnell ok. it runs very well!

i meant exhaust backpressure. or do you not need the back pressure with this engine?

[gbritnell]

@triggerdance

It doesn't need any backpressure. I have never experimented with doing that so I couldn't say if it would help the performance or not. I'm just glad it runs as well as it does given the number of bends in the intake and exhaust.

[triggerdance]

@gbritnell ok. does it have a govener? or will it just rev until the valves float

[gbritnell]

@triggerdance

It has a governor which controls the throttle. It can be locked in or out. I have never floated the valves. It runs out of timing and fuel control long before that happens. It has a very large flywheel on the rear and another smaller one on the front so it has a lot of mass to get spinning. It will rev to about 5800 rpm before it runs out of breath.

[triggerdance]

@gbritnell cool! so it would just stop revving and slow down to an appropriate level for the distributer to dish out the sparks? how did you get it to sound so beefy? i mean it sounds better than the real thing! man id love to start building a simple engine. how long would it take you to build a single cylinder gas engine with push valves?

[triggerdance]

@gbritnell have you ever thought about a 4 cylinder inline with a over head cam? i think it would really add some more depth to your creations! or a boxer engine in those old beetles.

[GermanBeez]

i like the litlle exhaust lid, its really cute!

[Tinsby]

Very nice work! That thing sounds wonderful and it must be set up right, you can start it easily. How long to build something like that? Thanks for a nice posting!

[gbritnell]

@Tinsby

I have about 1000 hours of build time because everything but the manifolds was scratch built from bar stock.

[gentharris]

Very nice I need to get back to work on mine!

[614gso]

Sound like a Moskvich 408) Cool!

[Dragon150043]

now THATS the sound of a Holt ! Nice project :)

[gbritnell]

@Dragon150043

Thanks, It does have a cool sound.

[jack9102]

the governor/throttle linkage controls the spark advance by rotating the distributor assembly, right?

[gbritnell]

@jack9102

No it just controls the throttle on the carb. I suspect the original full sized engines had fixed timing in those days. I have a lever on the points that I can change the timing while it's running but it doesn't seem to make a lot of difference.

[richardarichter123]

looks like a simple engine

[ideeman1994]

What a nice sound!

[buderboi]

WOWWWWWWWW, that is a thing of beautyyyyyyyyyyy!!!!!!  Gary Dr Tune! ;-D

[MegaZsolti]

that is just plain ..... awesomizingozorzful!!!

:D

[Pharao123321]

really nice! the sound..its amacing! :)

5/5* <3

[rhyslikeshardware]

@SthealthRaider .. You're a bit cranky towards him, you're asking him.. you could be nicer..

Anyway, Nice engine!

[Bobbymitchell10]

that is a amazing engine

[alexsullivanbanjos]

I could'nt tell you how much I would LOVE to have this engine!!!

[engineman327]

George, now that I watched your engine run...I want to finish my Holt engine. I may contact you soon!!! John, West Mich P.S. Super good work you done!

[c15driver]

impresionante!!!

[gbritnell]

gracias

[SthealthRaider]

how u time the valves

[gbritnell]

I'm not quite sure what you mean. Do you mean what are the cam timing specifications?

[SthealthRaider]

how do you time the ignition and how do you time the valves

[gbritnell]

The valve timing is as follows.

int open 25 BTDC

Int close 30 ABDC

ex open 25 BBDC

ex close 30 ATDC

The ignition is timed at about 15 degrees initially.

The points can be adjusted once the engine is running. It is usually set about 25 degrees at that point.

[SthealthRaider]

aahhh... u dont under stand me! i mean the mechanism of the spark timing and valve timing

[gbritnell]

The valves are timed by way of a camshaft. The camshaft is geared to the crankshaft at half speed. The spark timing is controlled by a cam that spins at the same speed as the camshaft. The cam has four lobes on it and they open and close the points at the proper time for each cylinder.

[SthealthRaider]

Thanks!! i finally understand it!

[gwheyduke]

Very nice build job, and congratulations on getting your engine running so well.

[jack9102]

thats amazing! i just compared the video of the holt running before this and-wow! the difference! you've done an excellent job on this engine