DEMON 2X

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

bruski

Well-Known Member
Joined
May 9, 2017
Messages
47
Reaction score
13
I machined a original size and a 2 X double size Demon oil pan for comparison. There was enough chips to fill my 10 gallon shop vac by the time I was finished milling the pockets. Also, I ground a cam for the 2X Demon with 112 degree lobe separation just in case I super charge it later on. The double size rods are almost as big as the original oil pan.

Bruski
Demon oil pan original and 2x.JPG
 

Attachments

  • Demon Grinding cam.JPG
    Demon Grinding cam.JPG
    179 KB
  • Demon 2x cam and rods.JPG
    Demon 2x cam and rods.JPG
    84.7 KB
  • Demon 2x milling block.JPG
    Demon 2x milling block.JPG
    248 KB
  • Demon oil pan milling.JPG
    Demon oil pan milling.JPG
    246.1 KB
Nice work!!
How do you calculate the profile of the master cam template?

Thanks!!
 
I followed an artical in Strictly I.C. magazine 1994 Oct./ Nov. issue page 28 on Master Cam Design by Don A. Bell. Using Steve's cam profile scaled up x 2 gives a base circle of .700 and .140 lift with a flank radius of 1.392 and a nose radius of .062. My master cam has a 2 inch diameter base circle. The radius of the desired cams diameter has to be subtracted from the master cams radius so ( 1.0" - .350" = .650" ) Now add .650 to all the radii on the desired cam. The radius origins remain the same places. The flank radius becomes 1.392+.650=2.042 the nose radius .062+.650=.712 and so on. I hope I didn't confuse you too much. Pictures or drawings are available on this forum somewhere on cam designs.
bruski
 
Any suggestions on how to hold the block for machining the top flat area? The bottom has a 90 degree point to it still. I am thinking about removing the vise from the table and setting the pointed bottom of the block in one of the t slot's, then clamping the two sides below the cylinders where I could mill a small pocket on each side to clamp on. The small pockets would be milled away when the sides are milled with a ball mill.

bruski
 
Thanks for your reply John. That sounds like a good idea.

bruski
 
Thank you! I'll have to sit in front of my computer to translate it into cad.

Camshaft grinding appears at the beggining to be a simple task, but when you dig into geometries, ratios and so, it becomes a complex issue.
 
I have found that locating the lobe centers for each cylinder on a V8 is the most difficult part for me. Following the firing order plus cylinder location not to mention the valve order on the heads, there is still the 90 degrees between the right and left bank.

bruski
 
Just one more question: Must the diameter of the follower to have a certain proportin in relation to the grinding wheel diameter? Thank you very much.
I am unable to find the Strictly IC number you mention.
 
Yes, I believe the follower should be the same size as the grinding wheel. But I have ground several different cams with different master cams of different sizes and I can't tell any difference between them all. My follower is smaller than my grinding wheels using the two inch diameter master cam I just turn the crank slowly and keep the feed lite cuts. Your master cam needs to be smooth and well blended where the flank radius starts and stops. If not, it will show up on your lobes. I will try and find a picture of the article and post it.
bruski
 

Attachments

  • master cam designing.jpg
    master cam designing.jpg
    220.5 KB
Thank you one more time!! I´m very proud of this community. In such an activity as engine making, you´ll need technical support sooner or later and this forum is full of people like you willing to do it.
 
While looking at the above picture the main bearing cap holes look off center on some, it is an optical illusion from the camera angle I guess. I will try and take better pictures in the future.

bruski
 
That's because the flash caused some glare. Try lots of light, natural light if possible and no flash. Warning, if you have a good camera other things might show in the photos like boo boos and owies that you might not want us to see.
 
Here is a size eye opener of the Demon cylinders both standard and 2X. Also, made the main bearing caps and rear bell housing adapter plate.

bruski
 

Attachments

  • cylinder size differene.JPG
    cylinder size differene.JPG
    197.2 KB
Line boring the main bearing caps has been at the limits of my equipment on hand. I first ball milled the three center bearing webs and caps with a one inch ball mill to a depth of .460. Then installed the caps and cobbled up a way to attach the block to a face plate on center. My plan is to line bore the three center webs with a boring bar that can reach the first two without any problems but the third one is out of reach. I planned on unbolting the block from the face plate and flipping it around to get the third one. But it took so much time and effort to get it all running true and centered that I would prefer not to do that again. So the setup will stay like it is in the picture until I either make a longer boring bar or come up with something else.

bruski
line boring block.JPG
 
I made a longer boring bar and finished line boring the mains. I then followed with a reamer through all five bearings. I plan to drill the crank for oiling of the rods so I am plotting the oil path through the block now. Probably going to make a belt driven gear pump on the front of the block that will feed the oil through a passage near the camshaft then to each center web. Since I will be using ball bearings on the front and rear crank mains, the crankshaft will be drilled to allow oil to feed the front and rear most connecting rods. Checking on the ball bearing sizes to work with the crankshaft and block now.

bruski
 
The valve covers are machined now with the Demon 200cc logo on them. I still need to hand finish them and maybe anodize them red or purple are what I have on hand.

bruski
Demon Valve Covers.JPG
 
I turned all 8 cylinders and locktited them in the block. The heads are just about done as far as the shaping and the ports and mounting holes. Still thinking about the oil passages in the block for the 3 center main bearings. The front of the block is ideal for a belt driven oil pump but the timing gears and cover are in the way of a oil passage. The rear of the block has plenty of room for oil passages. It could be driven off the distributor shaft like a chevy but the pan would need to be deeper in the rear end. Then there is a way to run the oil line down the side of the block with a passage drilled into each main bearing web. Or maybe drill a passage the length of the block and cross drill into the webs then plug the cross drilled holes on the outside.

bruski
 
Steve, you mentioned a non scaling compound while heat treating the piston rings on your Demon engine. What is the brand name or type of compound that you used please?
Thanks,
bruski
 

Latest posts

Back
Top