# V8 Challenger flathead



## henken (Dec 14, 2013)

Hello 
Thought I could share my engine build here at this forum. It may be a little late as it is kind of finished but anyhow...

Over a 2 year period I have been building the well known challenger v8 flathead. I bought the plans and casting set from Coles and started machining. 

15 cast parts has been used. Rest has been machined from raw material. 
Crank and camshaft made of 4130 steel.
Connecting rods are 7075-T6 aluminium. Running directly on crank
Pistons made out of 6082-T6 aluminum  
Piston rings made with George Trimble method.
3 piston rings used. 2 for compression and 1 as oil control ring.
Head gaskets made of Teflon.
Carburetor with float built from billet. Throttle borrowed from a rc airplane carburetor.

The center bearing for the crank is made of 7075-T6 aluminum and has been  redesigned a little to get more stiffness.
Starting system has been built with a motor from a electric drilling machine. The motor is fitted inside the wooden box and is connected to the flywheel with a belt drive and a one way clutch.

I had some problems on the road for example with drilling oil feed holes in the crank. On the first crank I broke the drill and had no luck getting it out.  
After some time collecting strength I went for a 2nd try and it was a keeper. I broke some drill bits on this also but fortunately i managed to get them out. 

I also had big problems with a diaphragm carburetor. I was not able to get the mixture correct with this carburetor so after several hours adjusting and trying different things i gave up. I tested a rc airplane type carburetor instead and the engine was running much better. A took the throttle drum from this carburetor and built my own which incorporates a float.

The engine has a 25,4mm Bore and 25,4mm Stroke. 103cc volume
It runs on regular gasoline 95 octane.

Video of the engine runnning can be seen on the tube.
http://www.youtube.com/watch?v=TyKyQjUpV_E

I aslo have many pictures of bits and pieces that can be seen on this link.
http://s1170.photobucket.com/user/hjoti00/library/V8 Challenger?sort=3&page=1

Enjoy


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## stevehuckss396 (Dec 14, 2013)

This is a good engine and you have done a great job on it. I was wondering what the castings cost you. I am thinking about doing one.


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## henken (Dec 15, 2013)

Thanks stevehuckss396.
Castings was  579 USD and drawings additional 50 USD.


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## stevehuckss396 (Dec 15, 2013)

Thank you. That sounds reasonable to me.


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## gbritnell (Dec 15, 2013)

What a beautiful build. I have seen several of these engines built and they all have a similar sound. It must be the cam configuration because my V-8 doesn't sound like that. 
 gbritnell


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## sition (Dec 11, 2022)

The HI~image is invalid. Let me see if there is a new link


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