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OHV camshaft vs L-head camshaft |
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tomj
AMC Addicted Joined: Jan/27/2010 Location: earth Status: Offline Points: 7522 |
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Posted: Jun/17/2019 at 11:21pm |
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i picked up a flathead six in pieces from another forum member this weekend, a 1958 or 1959. we'd roughly compared camshafts via photos but now that i have two side by side i can, sadly, state that there is no value in the L-head cam as a regrind donor for the OHV. he OHV and L-head camshafts are tantalizingly similar. given that the L-head engine's valve lift of 0.340"
is achieved without the advantage of rocker ratio multiplication, i had hope that the L-head camshaft
would be a candidate for regrinding for the OHV. alas this is not the case.
here are the two camshafts compared.
(base circle measurement is approximate). the L-head cam profile is a sharp pointy triangle; a quick check with a ruler seems to indicate that truncating that pyramid to even the stock OHV duration would result in less overall lift. if the L-head cam had the same shaft diameter/base circle diameter it might be a decent base for an OHV regrind. but the problem with OHV regrinds -- too little metal to work with -- is even worse with the L-head cam. there is also the issue of the absolute height of the base circle relative to the camshaft centerline; an L-head cam in the OHV block woult have the lifters drop down further to meet the cam lobe. the adjusters may, or may not, have thre range to take up the slack. however, an OHV cam in a flathead block might be interesting, if
it weren't for the lack of lift. this time the lifter/follower might be
too deep (up into the block) but grinding would probably solve that --
but without the lift, what's the point? |
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1960 Rambler Super two-door wagon, OHV auto
1961 Roadster American, 195.6 OHV, T5 http://www.ramblerLore.com |
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vinny
Supporter of TheAMCForum Joined: Jan/05/2012 Location: Calgary Status: Offline Points: 2837 |
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Desperate times call for desperate measures. I wonder if anybody has ever welded onto and reground cam lobes?
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tomj
AMC Addicted Joined: Jan/27/2010 Location: earth Status: Offline Points: 7522 |
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oh there's tech for that, and it's old enough. metal spraying for one. it's pricey. but yeah. where the 1960's had a lot of engineering innovation, the 40's and 50's saw a lot of pharting around and making arbitrary changes. Nash poked about in later years with "improvements" but the new AMC appears to have done actual engineering. this old engine... what a mess. the flathead has a sort of lovely barbarity to it. i think it's in my future. |
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1960 Rambler Super two-door wagon, OHV auto
1961 Roadster American, 195.6 OHV, T5 http://www.ramblerLore.com |
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Jmerican
AMC Addicted Joined: Mar/29/2016 Location: Seattle, Wa Status: Offline Points: 585 |
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Tom, any further progress or idea in this area? Sounds like you may be working on both flatty and ohv. I’m not sure if you’ve talked to any cam grinders. There is Delta cam near me in Wa.
Could there be a blank laying about.? As a side note, I may be tinkering and working on a Flathead 196 as well. I’ve enjoyed following your adventures with the ohv.
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73Gremlin401
Supporter of TheAMCForum Joined: Mar/02/2013 Location: Stmbt Sprgs CO Status: Offline Points: 941 |
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That's the quote of the week right there. Ha! |
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73 Gremlin 401/5-spd.
77 Matador Wagon 360/727. 81 Jeep J10 LWB 360/4-spd 83 Concord DL 4-dr 258/auto |
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Trader
AMC Addicted Joined: May/15/2018 Location: Ontario Status: Offline Points: 6762 |
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Tom, not having one of these apart. Can you have the base circle of the stock cam ground and the stock OHV lifters shimmed?
May be cheaper then a custom one off cam or having to change engines.
This would provide more lift and keep close to the same profile. |
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tomj
AMC Addicted Joined: Jan/27/2010 Location: earth Status: Offline Points: 7522 |
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i have more photos and measurements, i'll post them soon. there's very little base circle to grind; it's like 20 thou above the rough casting. the L-had cam is a smaller overall diameter. you're more likely to be able to grind an OHV cam for the lhead! no one i know has ever found a blank cam. even 232 blanks are hard to find (though cam houses produce 258/4.0 cams so they have 'em). nothing, nada, zip, on 195.6 cam blanks. my engine builder knew some old timer cam grinder in idaho or something, thought he had one, but it was a 232. |
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1960 Rambler Super two-door wagon, OHV auto
1961 Roadster American, 195.6 OHV, T5 http://www.ramblerLore.com |
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Trader
AMC Addicted Joined: May/15/2018 Location: Ontario Status: Offline Points: 6762 |
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Time for the turbo then:
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