Degrees advance in a cam

[DeathBySnuSnu]

So i am changing a bunch of stuff with my engine and all my old favorite pieces is not what it needs anymore.
Eagle cams 2246 with 1.25 rockers has been a favorite for a bunch of years.

I just grew from a 2110 to 2387, fuel injected.
I do not have hugemongus head ports. They are mofoco 050's with some hand porting, 42in 37.5out. The chambers and step are taking some major rework to get right on the larger engine.

So i have gotten my first ever engle cam.
Went with a fk10 and 1.4 rockers.

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This engle cam came in larger in duration than expected, even borderline to big. Was expecting 266 to 268 like advertised. Almost wish i had gone web 86c now knowing the fk10 is larger than advertised. But i dont want to run the compression required to make the web run.

So here is the question...
Degreed the fk10 and it is right under 3 advanced.
I dialed it in to straight up.
Does this cam need to be advanced that much?
I am not expecting an 8000 rpm drag motor.
I do want it a bit softer on the bottom.
But it needs to pull hard, i run a big gear.

So i am second guessing myself.... again. I have been told the fk10 is too much cam. But crud...it aint that much more than i ran before.

Comments?

[Dan Ruddock]

How much duration did you measure @.050? I have found the card and actual don't always match.

What rockers are you going to run? your old 1.25 or 1.4's?

Are your 1.25's stock style?

Yes I would run the cam 2-3 degrees advanced.

The cam is not too much for carbs but on injection I am not so sure.

Dan

[DeathBySnuSnu]

I do not have any kind of digital plot device.
Old school degree wheel and dial indicator. Search down a point at a time.
Everything was within the thickness of the line on the degree wheel. So i would guess within a quarter of a degree variation. Probably a higher degree of error with my eyesight than the cam.

Yes i switched to 1.4 rockers., both old and new are the adjuster on pushrod side. The old are gone and on a buddies scooter.

The old engine was a bit twitchy in the city. I dont do much city, just a couple stop lights at the most. A bit softer on bottom would be nice sometimes.

I read that injection and the tunability can make a big cam more drivable.

[Dan Ruddock]

Degree wheel and a dial indicator with a studed lifter is all you need to check duration.

Dan

[DeathBySnuSnu]

And......like i said
It is within the degree of accuracy using a wheel and indicator as can be seen with the eye.
So sorry... i am used to working to 4 decimal places.

[vugbug68]

Well you did increase your displacement by quite a bit so that should cancel out some of the duration of the FK10, I'd say it looks pretty good... on paper at least.

what compression?
_________________
71 Super - Backroad Thrasher
66 Corvair - Weekend Cruiser
90 4 Runner - Muddin

[DeathBySnuSnu]

So are you saying leave it straight up as the card specifies?
Or advance it like it is actually made?

Target compression is 9.5 to 9.8 range.
Zero piston to cylinder deck.
.050 copper ring gasket
59 to 60 cc chamber.

Lots of work to make the head chambers fit the larger displacement.

[modok]

1-3 degrees advance is usually where you want to be.
You got very lucky!

[Bajaman65]

Maybe I am not looking at the picture correctly but is sure looks like you have the washers on the Retard side, the cam should be pushed counter-clockwise to advance Sorry if I am wrong due to the side ways picture.
but you should double check this. I run my big cams at 3 -4 degrees advance to get better low and mid power.

[DeathBySnuSnu]

Modok,
so your saying run it a bit advanced then? I usually run cams straight up by the card. That is unless i want the cam to do something other than it was originally designed for. Which leads me to asking the question about advancing because the cam is a bit larger than i expected .

Bajaman65,
Yes the cam is dialed in to straight up to match the card. As the cam indicated 3 advanced i therfore have retarded it 3 to put it at zero off from the card.

And yes I do seem to be very lucky with all my parts.
The h beam rods were within 0.3 gram of each other. One being heavy on the big end that much.

The mahle Pistons were within 0.8 gram. With all being a small different.

[modok]

Hmmm, so you think the card knows best eh?
How bout this one
http://johnmaherracing.com/wp-content/uploads/2013/02/fk10.jpg

[vugbug68]

I'm gonna say run it 3 degrees advanced from the card, so don't retard it to match the card, more advance means more bottom end usually
_________________
71 Super - Backroad Thrasher
66 Corvair - Weekend Cruiser
90 4 Runner - Muddin

[jfats808]

Bigger cams I aim for 1 to 2 degrees advance myself. I'd run it straight up 3 degrees advance if that's what your at.
_________________
2276 IDA's 86C 11-1 DD !
2017 48 Trijet DRLA's W125

[Alstrup]

[DeathBySnuSnu]

Just looked. I dont have pics of the ports. I am headed out the door to work now. But i will try to get the info up soon, just not today.

The heads are 050's
The generic idf intake manifolds would need lots of weld up them to blend into correctly.
So i made intakes to match the port, just a little larger than head so i could clean up the head and match it in slick.
Most of the metal removal type of port work is only opening it up around the valve guide.
Nothing huge about the ports.
Exhaust is buff and fluff only.

[DeathBySnuSnu]

Ports.
Unfinished. But are as big as they are gonna get this time.

[DeathBySnuSnu]

Intakes.

[DeathBySnuSnu]

Chambers

[DeathBySnuSnu]

Previous cc check had the chambers around 59cc.
I got a real burrette, now to give them a better check.
I dont have guides in the intake side, so a cc check of port volume is still a while away.

[Hustlers67]