Chevy V8 Scale Engine Plane

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Cogsy

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I always see if I can get the ruler to bend ever so slightly towards me. Then I know for sure, I'm below center.
Lower than center on a parting tool is not the recommended way to set it up. If your parting tool isn't sticking out much then bang on center is best but if you've got a bit sticking out then slightly (very slightly) high will account for some flex in the blade and get you back to center. If you're a bit too low you run the risk of the part riding up over the blade as you get to the center and potentially wrecking the part and the blade/insert.
 

davidyat

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Thanks for the advice. Most of my parting is on soft metal, brass, aluminum, etc. Yes there is a slight nub after parting, but I'm cutting the part a little bigger than I need it and mill it down to what I want with a fly cutter on both sides. If I'm doing multiple pieces, I face off the round I'm working on for the next piece, zero out the parting tool and take it to the dimension I want. Most of the time, by the time the parting tool gets close to center, the nub is so small that the weight of the part causes it to just fall off. But, again, thanks for all the advice. I never want to stop learning.
Grasshopper
 

SailplaneDriver

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After a long break, I finally got all the rocker arms and rollers done but the roller pins are my new issue. My ER32 metric collets won't grip the 1/16" stock and I don't have a 5C 1/16" collet. Will order one and go that route.

I'm looking at making the valves next so I can finish up the heads. I need advice on how to turn the stems. I've found recommendations for step cutting, using a follow rest, a center, a female center, and Joe Pie's single cut to diameter. I think these are in the order of complexity high to low for cutting. What do you guys do? These valves have .094 diameter .866 long stems and I anticipate using .25 drill rod for stock. I could go to larger stock to improve stickout for Joe Pie's method.
 

johnl

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I used a center. I left the stem 1" long and used a #1 center drill. Trimmed to length.
I tried the step method but didn't have much luck.
 

John Antliff

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Jo Pie's method is certainly quick once you have the right setting however you don't have any control of the surface finish although you can cut slightly oversize and reduce using a file and emery paper. Slowly slowly catchee monkey for me! I've used the step method but once again you have to reduce the length tothe required size with abrasive to remove the inevitable steps. A centre is the time served method which works!
 

Cogsy

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I only ever make them using the step method but generally my stems are a bit bigger at 1/8". I aim to hit +0.01mm oversize to allow me to blend the steps with wet and dry and have them polish up for a nice fit in the guide. Generally the very first step of the very first valve is the tough/slow one as I use a finished guide as a stop/go gauge to get my number to aim for. From there it's not too difficult a task and it's fairly rare to mess one up. I do try to make them all in one session once I get into the rhythm. 1/4" stock sounds about the right starting size to me.
 

deverett

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Or consider two piece construction.
Use the correct size rod for the stem, put in the groove/cross drill for the retainer, cut off a bit longer than required. The extra length is reduced so the head won't slip up the shaft then silver solder a piece of stock to that. Hold the stem in the collet and finish machining the head. You can use the extra length and put a screwdriver slot in it for lapping valve and seat. Finally cut off the extra.

Dave
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justintime

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Sailplane,
I had so much stickout of the parting tool that it was just slightly above center height.
My machining mentor taught me a simple method that has been working for me. Take a 6 inch stainless ruler, run your cutting tool to the work, put the ruler in between the cutting tool and the work with very little pressure holding it. If the top of the ruler bends away from you, you're too high, straight up, your probably at center. I always see if I can get the ruler to bend ever so slightly towards me. Then I know for sure, I'm below center.
Grasshopper
Never use the cut-off tool below center. Dead on or a few thousandths high is preferred. Scale method is really only applicable when doing full cut off operation, to get " close enough " to what your machine can handle without " fighting " the tool. Good Luck.
.
 

SailplaneDriver

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Got all the rocker arms done a bit ago. Holding these tiny parts was a real challenge. I accidently juggled the container I had the rollers in and tossed them all over the shop. I found three of the 12 I had in the container. The rest are keeping the dust bunnies company.

P1260972.JPG


After numerous attempts I finally succeeded in making one valve. I settled on a step method with a single cut to depth with roughly .25 steps. Only 15 more to go. I still have to put the seat on the valve but I'll do the valve seats the same time as I do the valve cages to make sure I get them at the same angle. These miniscule parts are a pain - very easy to shear off if you aren't very careful. And don't drop them otherwise you'll never see them again.

P2160974.jpg
 

stevehuckss396

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Did you deviate from the drawing? It looks like there is a radius cut into the under side of the rocker by the roller.
 

SailplaneDriver

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Steve, you have a good eye! The one on the left does have a radius where I overturned the rotating table. I used it for a test fit. The image below is a bit closer and should show in better detail the spring relief. I don't believe I deviated from the plans. All of the other rockers match this one - well at least half since the other half reverse offset.

P2170975.jpg
 

rmalsen

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This is awesome , this is what I wish to make can you help out Cheers Rob
 

bluejets

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I just bought the plans for this and the blower , they are very good , but not sure if I will make it very easy as I only work in metric
In most instances it doesn't really matter so long as it is a close conversion.
Critical point is that whatever you make your part it matches your build.
1" = 25.4mm works for me.
 

rmalsen

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In most instances it doesn't really matter so long as it is a close conversion.
Critical point is that whatever you make your part it matches your build.
1" = 25.4mm works for me.
thanks for the heads up
 

SailplaneDriver

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One completed head. I finished the other head first but the valves wound up proud. Steve Huck indicated that there is only .017 clearance between the valve and the piston if everything is built perfectly and I know that isn't going to happen with my skills. I'm in the process of removing the offending valve cages and making new ones. I should have two complete heads shortly.

IMG_20200412_095432.jpg


Installing the e-clips onto the valve while holding down the spring and spring retainer can get real exciting. One slip and the spring retainer gets ejected at lightspeed somewhere as it bounces of you, the ceiling, walls and whatever other surface is close. At .21 diameter they are darned hard to find. Fortuately I made extras in anticipation of launching them into the abyss. With my luck a cat will eat one and need to go to the vet.
 

rmalsen

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Got all the rocker arms done a bit ago. Holding these tiny parts was a real challenge. I accidently juggled the container I had the rollers in and tossed them all over the shop. I found three of the 12 I had in the container. The rest are keeping the dust bunnies company.

View attachment 113885

After numerous attempts I finally succeeded in making one valve. I settled on a step method with a single cut to depth with roughly .25 steps. Only 15 more to go. I still have to put the seat on the valve but I'll do the valve seats the same time as I do the valve cages to make sure I get them at the same angle. These miniscule parts are a pain - very easy to shear off if you aren't very careful. And don't drop them otherwise you'll never see them again.

View attachment 113886
what do you make the values from ,what do you make the valve case from , and where can you get 1/16' drill rod x 1.475 long from for push rods
thanks I'm new to this just starting my build
 
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