277 rephase technical question

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AllanCaveNZ

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Is there a reason most things I've read on engine rephasing mention the right cylinder firing 277 degrees after the left (or left being behind right by 83 degrees) rather than the other way around? On my 277 engine the left piston fires and then 83 degrees later the right piston fires.

Is it just that some cams are built with right following left rather than left following right or can it just be installed either way around when building it?

It's probably an unnecessary question but it made me curious, was just installing a new ignition when I noticed it.

Thanks
 
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Allen at risk of confusing you further I will say this:

My rephase fires the same as yours.

The way I think of it when viewed from the alternator is the Right leads Left by 83 degrees.

I have done a few rephases and the first one was the hardest to get the thinking right. You end up thinking in circles.

I have found it easiest to ignore the right side initially and set the left up as standard. I only think about the Left side if I try to think about both sides it leads to frustration.

Once happy with the left check the right but there is not a great deal that can be done if the crank was not moved enough or the cam was ground incorrectly apart from reworking the incorrect part.

I haven’t thought to much about the cams all the ones I have seen have had the threaded end lobes repositioned.

Never considered the possibility of reversing cams on a rephase, it is possible on a standard firing XS.
 
Thanks for the reply, good to know other ones out there are done that way too. It all seems correct other than the old ignition which I’ve now replaced with trispark but haven’t fired up since installing.

When firing it up my static timing may have been a bit rough but shouldn’t be far off, had to find and mark TDC and then set it at 40 degrees earlier since it has electronic advance. Should I err on it being a bit more advanced than needed on first start rather than risk it being a little more retarded? Any chance of doing any damage if it’s too far either way?
 
Retarded is FAR preferable to over advanced.
I'm not a 277 maven but yes I believe they've been built both ways.
If the cam is backwards I think a valve would hit a piston.
 
As a suggestion try 35 degrees then adjust from there if you think its needed.
 
did you do the rephase? There was an Australian that made new crank pins and did a true 270 degree rephase not a 277. Might be worth ensuring you don't have one of those?
 
Please report back on what timing you find works best with your engine set up.
 
Will do - it'll be handy having dyno there to prove what's working best.

It was actually built by Daryl Hutcheon who did the 270 crank pins but he'd stopped doing those by the time he did my rephase and only offered 277 rephases I believe. Lack of demand and cost of additional parts for the 270 rephases. I moved back to NZ shortly after he did my engine up and shipped it back here but ignition was malfunctioning and he was unwell and unwilling to offer advice, I put it in storage while building a house and been sorting it out recently.
 

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