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The cam was cut for 1.8 rockers. The geometry on these heads end up different so i ended up with 1.73 otherwise would have to modify 1.8 rockers which I didn’t want to do. I checked actual lift yesterday and its 748. Cam is 435 lobe.
Thats actual lift with real springs? I would expect more loss than that. So .748 lift rather than .780 may be part of it.
 

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Long Live The King
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Probably not hanging valve open long enough.
adding 6* more int duration and maybe 4-6* on the exhaust.

But what is the rpm target ?
 

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Your problem is not intake carb or intake lobe, you have to get the cyl. evacuated on those or it can't fill , doesn't matter what you do on the intake side if residual pressure in the cyl. is still high when the intake valve opens.
 

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Your problem is not intake carb or intake lobe, you have to get the cyl. evacuated on those or it can't fill , doesn't matter what you do on the intake side if residual pressure in the cyl. is still high when the intake valve opens.
Think you would you see that intake reversion with a very fine piezo type pressure transducer connected to a scope? Increase exhaust lobe 10* or so to help evacuate cylinder?
 

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Your problem is not intake carb or intake lobe, you have to get the cyl. evacuated on those or it can't fill , doesn't matter what you do on the intake side if residual pressure in the cyl. is still high when the intake valve opens.
So you are saying header is to small or lift on exh side? Or both
 

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So you are saying header is to small or lift on exh side? Or both
l
No I'm saying you need more exh. duration, maybe even less intake duraton, I don't particularly like the 112 LC, Exh. lift is not an issue, those BT heads actually have too big exh. valve that's part of the issue. You need about 12 deg more exh. duration than intake on that combo and that intake is not the best choice. Bottom line is the cyl. pressure has to come down so the intake charge can start to move. Doesn't matter what you do on the intake side until you address that issue.
 

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l
No I'm saying you need more exh. duration, maybe even less intake duraton, I don't particularly like the 112 LC, Exh. lift is not an issue, those BT heads actually have too big exh. valve that's part of the issue. You need about 12 deg more exh. duration than intake on that combo and that intake is not the best choice. Bottom line is the cyl. pressure has to come down so the intake charge can start to move. Doesn't matter what you do on the intake side until you address that issue.
So you figure a cam like 270 intake 282exh ?
 
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