All Small Six Dynamic compression

This relates to all small sixes
I ran that Clay Smith 274 cam & i hated it. great top end, but no low end or midrange.
If you are not satisifed with it get a cam with less duration faster rate of lift & more lift.
Wish you the best.
Do you remember what rpm it idled at and what rpm it started making hp?
 
Thanks Bill, at this point, I think I am just going to see how it plays out. Do you know what your compression was? Mine is a little higher than I would have planned. Running a smaller cam would raise my dynamic compression a few more points…it’s high already. Then there’s the valve springs, the ones I have are probably a little stiff for a smaller cam. I ran two other clay smith cams on the calculator, a 267 and a 256. It put the DC at 8.5 and 8.7. They only thing I am sure of is I want to run ethonal free gas and hopefully don’t have to add a booster.
I think I will run it, worst case is if I don’t like it, pull the head, enlarge the chambers a couple cc’s, and if needed do the cam swap then. The only thing I would save by doing it now is maybe a set of lifters. I have cheap labor 🤣🤣
 
After reading some of the current posts, and not seeing any reference to the head I have, and in light of my build pushing the limy( at least of what I want), I thought I might get opinions on how my head fits into the build. Please remember it has been modified for 2 barrel carb. The numbers are: C4AE-G
Thanks in advance 👍
 
Don
The DCR knock index for the 300 big six is between 7.0 to 7.5 for pump gas octane of 87 to 91 respectively.
The small six with it’s smaller cylinder bores
Is between 7.5 to 8.0 but that is with the current E10 pump gas.
We don’t know what the detonation index is with ethanol free 91.
If you want to have margin, you could pull a few CCs out of the combustion chambers if there is a good place to do so.
What does the chambers look like?
Hey mate do you know these figures for the small sixes a 250 in particular?
 
Hey mate do you know these figures for the small sixes a 250 in particular?
I know that the smaller diameter cylinders are less prone to detonation than the 300 sixes but we don’t have any data or feedback from the small six engines to pinpoint any numbers.
 
I know that the smaller diameter cylinders are less prone to detonation than the 300 sixes but we don’t have any data or feedback from the small six engines to pinpoint any numbers.
No worries getting detonation with 98 octane
And 8.9 dynamic. Can only get 24* total into it
 
No worries getting detonation with 98 octane
And 8.9 dynamic. Can only get 24* total into it
Is that 98 octane AKI (USA) oder 98 octane RON (Europe)?

And do you know how much psi cranking compression you got per cylinder?
 
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@64xm Thanks a lot for the numbers!

I edited my post, I got the AKI, MON and RON all mixed up!
When I read your answer, I just realized Australia and Europe use the same octane rating system (RON)...
 
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