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CAL(KS) 
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Joined: 18 Sep 2009
Location: Chapman, KS
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 Topic: UM engine specs/info advice
Posted: 05 Jun 2024 at 8:17am |
I know this is likely a long shot but Im in the final stages of paper calculations before I jump into custom pistons. I would like to know valve lift and nothing is listed but degrees at which valves open and close. No cam specs available either. i can measure lobe height with a digital caliper and get close but rocker ratio is unknown and center to center measuring seems like precision is out the window too. Even the deck height I've had to calculate with known stroked crank, 1.5 ch BBC test piston and custom length rod.
Stock arm ratio on model A and WC-WD is 1.45 per Murphys Motor service. Could a guy assume 1.45 for the UM and see if measurements are close? Assume nothing since the UM was designed by Waukesha? Maybe it doesnt matter as the head chamber is so huge I dont know if i will ever get close enough to the valves? Valve faces when closed are in the neighborhood of 1 inch above the deck. I have a running engine but i would hate to crack it open to try to measure this, but may be the only option. This is a 1 time shot i cant afford to screw up. What do you guys say?
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Me -C,U,UC,WC,WD45,190XT,TL-12,145T,HD6G,HD16,HD20
Dad- WD, D17D, D19D, RT100A, 7020, 7080,7580, 2-8550's, 2-S77, HD15
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NEVER green
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Joined: 28 Feb 2013
Location: MN.
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Posted: 05 Jun 2024 at 9:30am |
There are you tube videos on how to check valve clearance with out pulling heads.
If it were mine I would not worry about valves, set your compression height then you can cut your valve reliefs latter, especially after you get your cam reground by CamCraft. 
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2-8050 1-7080 6080 D-19 modelE & A 7040 R50
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CAL(KS)
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Joined: 18 Sep 2009
Location: Chapman, KS
Points: 3777
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Posted: 05 Jun 2024 at 9:47am |
wont do any good to measure valve clearance on running engine as getting different pistons for build. would like to know valve lift for new piston design though. think i can pull the gas tank and valve cover to measure head to top of valve at closed and lift. Got a link for Camcraft info?
Edited by CAL(KS) - 05 Jun 2024 at 10:05am
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Me -C,U,UC,WC,WD45,190XT,TL-12,145T,HD6G,HD16,HD20
Dad- WD, D17D, D19D, RT100A, 7020, 7080,7580, 2-8550's, 2-S77, HD15
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PaulB
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Joined: 12 Sep 2009
Location: Rocky Ridge Md
Points: 4495
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Posted: 05 Jun 2024 at 2:25pm |
It seems like it would be easy enough to measure valve travel on your complete running engine just by lifting the valve cover off and measuring the total open height and the total close heights and subtract the smaller from the larger, that would be total valve lift. I understand that you will be using a reground cam for your new motor, however you should have a cam chart for that and you can compare the findings of your running engine to the new cam chart. Also if the head of the valve it an inch or so from the head surface, I doubt that valves will ever get close the the flat top pistons. The roller cam I ran in my Blown/injected 440 engines that were on the last unlimited modified I ran had .750 lift at the valve.
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If it was fun to pull in LOW gear, I could have a John Deere.
If you can't make it GO... make it SHINY
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CAL(KS)
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Joined: 18 Sep 2009
Location: Chapman, KS
Points: 3777
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Posted: 05 Jun 2024 at 3:05pm |
 PaulB wrote:
It seems like it would be easy enough to measure valve travel on your complete running engine just by lifting the valve cover off and measuring the total open height and the total close heights and subtract the smaller from the larger, that would be total valve lift. I understand that you will be using a reground cam for your new motor, however you should have a cam chart for that and you can compare the findings of your running engine to the new cam chart. Also if the head of the valve it an inch or so from the head surface, I doubt that valves will ever get close the the flat top pistons. The roller cam I ran in my Blown/injected 440 engines that were on the last unlimited modified I ran had .750 lift at the valve. |
Yes, what your saying about open and closed valve travel is what i was thinking, just didnt have it worded coherently. I have a cam core i was considering getting reground to add a little umph. I emailed a cam grinder to ask about stock cam spec and what might be available to do a mild regrind. No information I can find shows any cam specs other than degrees of opening and closing.
cam grinder sent me this--" stock grind for that engine is intake .245 lift and 178@.050 the exhaust is .250 lift and 184@.050 depending on if you are staying with stock rocker arms"
----edit. this seems tiny but the valves are 2" and motor turns max 1400 rpm
He suggested ".330-.345 lift and durations right around 200 a lot depends on what the core is able to accept"
Now the real question is what static compression ratio, and cam grind will let me run 91-93 octane fuel and stay alive. this will be a div2-3 natpa tractor, i dont need wild numbers that will tear it apart.
10 to 1 static compression is going to require ~.400 into the head chamber because its so large. what style flat or dome will be determined by piston maker from my head chamber mold, which is why i need to have some cam numbers to pass along.
my NA 69 Plymouth with the 383 is only running .488-.491 
Edited by CAL(KS) - 05 Jun 2024 at 3:22pm
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Me -C,U,UC,WC,WD45,190XT,TL-12,145T,HD6G,HD16,HD20
Dad- WD, D17D, D19D, RT100A, 7020, 7080,7580, 2-8550's, 2-S77, HD15
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PaulB
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Joined: 12 Sep 2009
Location: Rocky Ridge Md
Points: 4495
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Posted: 05 Jun 2024 at 8:21pm |
opinions may vary and some engine particulars will also have a bearing. I would be comfortable running good quality pump premium with 10:1 compression. however my first choice of fuel for a spark ignition puller engine would be E85. This requires a big change in jetting, both load and Idle. An EGT gauge is a tremendous help for this. My second choice would be propane. The idea of paying $20 a gallon for race gas is ridiculous.
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If it was fun to pull in LOW gear, I could have a John Deere.
If you can't make it GO... make it SHINY
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CAL(KS)
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Joined: 18 Sep 2009
Location: Chapman, KS
Points: 3777
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Posted: 06 Jun 2024 at 7:31am |
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In my area E85 isnt available, I am not aware of any place to get locally. Maybe it is I just dont pay attention as i never use it. 91 is my best option and even then its a trip to the next town over. Im not interested in getting into $20 a gallon fuel at 40 mile trip 1 way, and the reason for staying with a mild build. (well and $$$). I am not against adding octane booster in small quantities if we go over the safe zone a bit.
Edited by CAL(KS) - 06 Jun 2024 at 7:38am
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Me -C,U,UC,WC,WD45,190XT,TL-12,145T,HD6G,HD16,HD20
Dad- WD, D17D, D19D, RT100A, 7020, 7080,7580, 2-8550's, 2-S77, HD15
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