renegade intake? for cross fires

DCR of 8.0 looks good with 91 octane, going any higher would be getting into the unknown gray area.
There is NO ONE NUMBER where detonation starts. Too many other variable to consider .....
A/F, timing, air temperature, combustion chamber shape, size and surface texture. Polishing
the chambers can help with detonation.
 
DCR; How low is to low, and what are the effects?

And I do plan on polishing the heads up nice and pretty once I get them.
I won't do much with the pistons and risk getting some polishing compound or aluminum oxide where I don't want it... however they are nice and carbon free!
 
What is the max DCR I would want to run?

And I was able to find a 5cc relief in my pistons using the pn on top.
I also measured the top of my bore, and it looks like 4.060 gasket would be a perfect fit, I'll double check the measurement.

Also the original headgasket varied big time, smallest reading I got was 4.060, largest was over 4.1

Using those numbers I have this...
upload_2015-11-3_13-8-0.png

So I can advance the cam timing to bring it up, and retard to bring it down...

And I have a degree wheel on it's way.

Also my new camshaft has some kinda sharp edges on the lobes, would it be a good idea to soften that up a little, or leave it alone?
 
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your cam lobe edges never contact the lifter base (flat tappets)
lifter1jpg.jpg

or roller wheels (roller tappets)on cam lobes if the cams are installed correctly
rollerlifter.jpg
 
From the links (thanks grumpy)

DCR Octane #
7.1 87.5
7.2 88.0
7.3 88.5
7.4 89.0
7.5 89.5
7.6 90.0
7.7 90.5
7.8 91.0

7.9 91.5
8.0 92.0
8.1 92.4
8.2 92.8
8.3 93.2

So it looks like for sure the 70cc heads are the best choice in this case.
 
I can only speak to my situation and I'm running a SCR/DCR of 10.70/8.27. I do have a
small problem when I shut the engine off, it wants to fire a couple of cylinder before
stopping. Now maybe I did more for my combustion chamber than you have plans for
the combustion chamber, so reading my build thread for those detail maybe important
to running a DCR of 8.27.

My Crower camshaft had what I think you were talking about. I didn't like the looks or
the possibility of the metal particles coming loose during operation so I used a mill file
to radius those side edges of the cam lobe.

MushroomedEdges0526.jpg


To protect other surfaces while filing the edges I used masking tape on back side of the file.

FileWithTape0530.jpg
 
yeah, the other camshaft I exchanged did not have any sharp edges, and it also had a silver surface...

I did not check the date on the old one, however my new camshaft has a date of 2014 an it also has a black finish, and the edges of the lobes are a little sharp.
 
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Ok I got my camshaft degree wheel and I ran into a snag I never thought of, clearance due to the engine being in the car... :rolleyes:

the wheel is off by a good inch and a half!

I'm trying to think of ways to use the silly thing, so far the best idea I have is to copy the marks onto a piece of cardboard using a straight edge and headed towards the center so I can trim the cardboard to clear...

Other idea is I can unbolt the motor mounts and dust off my chain hoist, I have the car parked under the structure/hoist eyelets I built to hold the boat up a few years ago.
 
I would sure try to get the clearance you need, so you can use the wheel as is. Try that
first, then worry about an alternative if it does not work.

What diameter did you buy?
 
I bought a 9in

And I felt pretty stupid when it hit me, I was actually trying to go bigger too! :confused:
 
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Grumpy,

I don't believe what my eyes are seeing ...... are you putting text on a graphic. My gosh
you are moving up in the computer world !!! :eek:
 
yeah theres bloody trails along the tile floor , where my bloody finger tips failed to grasp the tile floor where I was dragged kicking and screaming, into the modern world, but ever so slowly I'm getting a tiny bit of computer skill, I still stand 12 feet away and poke at it with a stick from behind the wall, but hey its a start
images
 
I still stand 12 feet away and poke at it with a stick from behind the wall, but hey its a start

When are you going to start drawing STRAIGHT lines ...... will it be in my lifetime?

Now I'm the one poking something with a stick!!! hehehehe!!!
 
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