Ironhead A matter of degree (Pretty Pics)

[Ferrous Head]

OK. So I thought I had a problem with my new engine. First dyno run the engine only went to 4600 RPM and made 60 HP.
That pretty much had me floored. This is a small stroker stock bore 6 1/2" stroke. Dan Baisley did the head work for me. JE stroker pistons. S&S Super B fed by an electric fuel pump running Methanol. My own 2 into 1 exhaust system.
This engine should rev to 6500 no problems and make around 85HP.
I only did the run to get the air/fuel graph as I was just guessing at the jetting.
I thought I would be rich in the mid range and top end and maybe lean down low. Turned out to be just the opposite. But not enough to cause a serious problem. Running around 11 to 1 at worst.
But it just hit a brick wall at 4600 rpm. The tacho wasn't working so I did the revs by calculation.

Here's the engine.




So back home I look at everything I can. Timing was at 47 BTDC. I calculated it should be at 45. 2 degrees is no big deal. I subtracted 5 degrees for the dual plugged heads and then added 5 degrees for the Methanol. SO, back at 45.

That only left the cams as the culprit. But I was sure I had installed them correctly. I checked valve to piston clearances pretty carefully. Should have shown up there if it was a problem.
The one concern I did have is that when I checked the cranking pressure before doing the dyno run the number came up much higher than I expected.
Both cylinders went just over 200 PSI. With the Andrews X grind cams closing at 55 ABDC I expected the pressure to run around 160.
So my thinking was the cams MIGHT have been installed incorrectly or they were ground wrong. (That's happened to me before).

Nothing for it but to check the cam timing. Not as in "looking at the dots" but actual opening and closing points.

Ok here comes the rub. I have a degree wheel I've used on engines for 40 years. Works great. All that's needed is and adapter for the Sportster engine. No problems. Done - looks like this.




So far so god. But every other engine I've had to do this with had tappet covers. An Ironhead doesn't.
Without going to great lengths to make a tool to hold a dial gauge you just can't fo it. That tool is coming - takes me a while to make these things anymore.

In the meantime I've worked out by checking the duration that the lead in ramps add about 55 degrees. So add 55 to the 0.053 lift figure and I get 110 ABDC. I actually got 110 - close enough to tell me they aren't a problem.

I have sent a request for information to Andrews Tech Support re seat to seat points but not heard back from them yet. Might never hear from them. Oh well.

In the meantime I went back and looked at the video of the dyno run we did.

LO and BEHOld ! I can see the dyno operator shutting off at 100 KPH.

Not a problem with the engine I think now. He just didn't let the engine rev out. i wasn't in the room for the first part of the run but I do remember thinking it wasn't going to red line. I thought the last run was either 50 or 75% throttle.

When I look at the air/fuel graph I can see it actually goes nuts at 100 KPH because he just shit the throttle.

And if that's the case a LOT of worry,, time and trouble on my part for nothing. I still have to confirm everything, which I will but hell ......

OK So here's my question - There's always a question isn't there ?

Has anyone else dialed in the cams on an Ironhead and if so do you have a tool for setting the valve lift ? I've designed one and getting it machined up now but it just dawns on me I've been relying on the cam makers to get things right for 40 years. Not on my Ducati engines. Their cams were a bit "hit and miss". So I had to. ALL the Jap 4's I worked on we dialed the cams in as a matter of course.

My calculations show the front inlet is 2 degrees out but that's the margin of error with how I'm doing this. Just be nice to know I can tweak these things if I need to.

So show me your cam tools.

[CHOPTOP37]

well I can add some food for thought....
I use same setup, degree wheel on primary nut, dial indicator for tdc to setup wheel.
as for indicating open /close/ etc., I simply use a strip of bacon with a 5/16 hole drilled in the corner.
{now for you that don't know a strip of bacon is any kind of rectangular piece of metal,it must be used in the context of the job at hand, like east coast guys say" fughettabouditt"}
the 1/4 thick by 1.5"x2" said strip of bacon bolts to any or all lifter block studs, and I use it as a base for a magnetic dial indicator. pull the pushrods and tupes and get the indicator centered in the adjuster. done.
same tool mounts to rocker box bolts to indicate lift and timing at the valve and rocker, using an old set of cut open boxes.... an absolute must for any serious valvetrain work in my opinion.
I deal with a lot of different engines, auto, marine, gas /diesel, Kawasaki z1, to rubbermount evos on a weekly basis, and degreeing cams and cc ing for real compression calculation is always important to me as it can save the day in a lot of ways for proper output, etc...ok so what im saying is.... its important.
Now, that being said, im totally guilty of one mistake..not degreeing ironhead cams..until recently, why? because I always figured "what are you gonna do about it if its off?" realisticly theres no real feasible ways to change unless you have or make movable lobes.
so , I never botherd when degreeing the breather to check the cams, except years ago I had a set of Andrews in my stroker, as per usual the #1 cam marks were off enough that I couldn't decide which way was off less so I degreed the #1 cam and realized that what everyone else thought was correct timing was actually a tooth off... they where pretty accurate on the timing according to specs.
fast forward to last year..
got my norcal 69 all done, fresh 900, new everthing top to bottom. I figured a couple kicks and she' fire right up. wrong. I knew quickly something was not right, I couldn't get to even pop . I quickly discovered it had about half the compression it should on the front cyl. why? something I never dealt with, since I have very rarely used factory cams in irons..the #4 cam gear had spun the gear on the cam. and since the marks are on the gear, everthing looked cool, but I realized looking through the plug hole I had overlap at tdc no matter how many times I spun it over...haha jokes on me, this was a literal basket case motor so I had no idea...SHOULD HAVE DEGREED IT I KNEW BETTER.
fast forward to this year.
freshened up my 89". now I was curious because I sort of degreed this engine years ago, and I knew it had more lift than advertised..supposed to be 585 but measured at 600 +
now these are late sifton 217 by hilferty.
surprise. I only measured #3 back then, again, because what am I gonna do?
well I got schooled. that was the only cam with timing that matched the stamping on the cam. the other 3 are off from 2-6 degrees, both ways , even better one intake cam is already advanced 5, but has 10 more degrees of duration ground in! the other intake has proper duration but is retarde 5 so the closing ended up the same on both intakes,@65 degrees instead of 60.
heres the kicker.. I bought a set of hilferty 625 cams.... that stands for .625 lift... the timing is the same as my old 217s by the book. except one thing. they measure out at .600 ish lift , and the same exact timing, although a little more accurate to the timing, so basicly they are a re named version of the same thing... but still they are kind of all over the place compared to what im used to seeing on a day to day basis.
all the Andrews big twin cams ive used have been groubd accurate, some times the gear needs to be moved.
woods, screaming eagle, and comp have all been good although I know Andrews is grinding most everybodys bike cams now, because theres not really anyone left for small lobes.
all the inline four cams ive bought or had ground where right on, it was a matter of setting them up where I wanted them.
im going to degree a set of p,pb{Harley} and a set of mid sifton c grinds very soon, im lacking a set of assembled flywheels to put in some old cases, as soon as I get the parts to gether for mock up I will report my findings..

So now that all this rambling is over...my point is I hope your only problem is dyno operator error..
but in the future I would highly recommend degreeing , simply because one of my rules is
" don't THINK, ....KNOW.
when problems arise like this KNOWING the facts will cut down the list of "could be's" very quickly.
good luck with your new engine, hope this helps some one.

[CHOPTOP37]

i guess i have to add:
since where talking degreeing, using my cut open boxes and indicating lift at the lifter and valve has shown me a few things.. theres a lot of flex in the valvetrain esp. with high spring pressures..
and i haven't found a set of magical 1.43 to 1 rockers yet.

and you guys that like to split the boxes will be in for a surprise if you seen how bad the boxes flex.

[Ferrous Head]

You hit on the very reason I really never bothered with them until now. I can advance or retard with the Dukes and Jap engines but unless I buy a cam grinder I'm not going to be able to do anything about it.
My new tool will fit directly over the lifter and use a dial gauge (actually A Suzuki factory ignition gauge) So it wiill just be the cam numbers but I am aware of the differences you'll find at the valves. Just that drilling and milling the covers and ockers seemed a lot harder ( times 4) than making one tool.
I don't frag race this thing so not worried about 10ths through the quarter mile but just expected the engine to do"what it should" within it's specs.

Thinking back Idid 8 laps at Lakeside just to test the basic passage and my passenger said it would have krapped all over the sidecar he usually rides on. So it can't be THAT far down on power. And seemed OK to me other than a miss in the mid range.

[chevelle]

Andrews cams will be close.
Late Sifton are actually pretty bad like chop says.
I have a X graph if you want to see the real specs.
Easiest way to check if cams are installed properly is measure tappets.
http://www.nrhsperformance.com/tech_xlcaminstall.shtml

[needspeed]

You can advance or retard the whole cam set by removing the larger gear on the #2 cam and press it back on using an offset key. Aside from that, there's not much you can do to change the timing unless you can grind lobes or make gears.

You can play with offset keys and install the exhaust cams one tooth off for an experiment, but be careful you don't get valve to piston or valve to valve contact. I've fooled with this stuff a bit and never found an improvement.

Cam grinders give the timing specs at a certain tappet lift, so when verifying the cams accuracy that's all that matters. The cam grinder has no control over what is happening at the valve.

Lift and duration at the valve can be changed with different valve lash settings.

I'll bet Choptop can measure that with his cut open rocker boxes.

[Ferrous Head]

Chevelle if you have the seat to seat numbers I would love to see them. I re-did the cranking compression yet again with a virtually brand new expensive compression gauge. Basically the same as before. I'm getting 203 on the rear cylinder and 210 on the front. That's with a cold dry engine.
So I believe in relation to each other the cams have to be right. It's just that I was expecting the pressure to be a fair bit lower because of the lateness of the inlet valve closing - 55 ABDC.
But I never cc'd the heads and Dan Baisley did all the work on them. I gave him the pistons and cams I was using along with the stroke. Now it occurs to me I did not check to see if he milled the heads at all. It may well already be making 13 or more to 1 for mechanical compression. He knew the engine was going to be run on Methanol, so maybe he did that.
In any case I will either find out the seat to seat numbers or finish making my "lifter lift" tool and know exactly what's going on with the cams.
If the cams are OK (which I now believe to be the case) there is absolutely nothing wrong with the engine. I'll book it into another dyno place to confirm that and at the same time check my new jetting.
Oh ! while I'm on about that does anyone have a source for Super B jets bigger than 120 ? I can drill them but that's never very accurate and I'll probably have to experiment a fair bit. It would be nice just to have the S&S jets from 125 to about 140. If I had them I could probably do consecutive runs while the bike is up on the dyno and get it just right.

[chevelle]

If you do a quick base circle height check at tappet,
then do the same height check at TDC at tappet.
Subtract those and the difference should be .145" +/- .010"
If you get that on all 4 tappets, then you know the cams are correctly installed.

[IronheadLiam]

Hey Choptop.
What did you find when degreeing the P, PB cams?
I am running the same setup on my 69 and need to degree the cams bc it runs so poorly.
Thanks.