New Cams New Thread

[Claviger]

I won't go into specific timing event values, because, the values that work well on this engine were given to me by Neville and not my own product of testing.

They are the magic to making an engine run well.

Also keep in mind ramp rates at different areas can make two otherwise identical cams perform very different.

Imagine a straight shoulder cam with a wide 20 degree nose compared to a cam with massive shoulders that achieves .200" lift 15 degrees longer than the other but has a pointier 6 degree nose. With identical peak lift and duration at .04" numbers, the second will kill the first in power production if the intake runners have good low lift port velocity, as it has more area during the portion of the cam that is passed through twice. If the runner has garbage velocity but high flow at/near peak lift the first cam will do better.

Essentially the classic roller vs flat tappet cam debate of the V8 world.

 

[Claviger]

Sorry, another long post.

Timing using Tappet lift on the R3 is not the easiest thing as you all know who've been inside the head. There's not a lot of space for a dial indicator shaft.

Using #1 or #2 cylinder is nearly impossible to do accurately without esoteric indicator attachments, #3 has about 1/3 the width of the Tappet to use and is easy comparatively. How to do it though when the crank TDC mark is aligned to #1?

Here's how I did it
1: Use a dead stop to verify the accuracy of your TDC mark. Mine is 0.5 degrees off, not much.

2: Determine your cam timing events, for this exercise here are some made up numbers as the goal
IVO 10 BTDC
IVC 50 ABDC
EVO 52 BBDC
EVC 12 ATDC

3: Setup dial indicator on exhaust side, #3 cylinder, point lobes up to the sky, zero gauge. I found it easier to do exhaust first because of kickback issues with big cams.

4: Convert timing on cylinder #1 to timing on cylinder #3. This avoids loosening the timing wheel to move the wheel TDC mark to TDC on #3, as a side benefit, by leaving the wheel oriented to #1 you can quickly verify TDC using the marks to ensure no error snuck into your work.

5: How to convert:
A triple has 120 degrees rotation between cam lobes, but, cams turn half the rate of the crank. 240 degrees crank rotation = 120 degrees cam rotation. So if #1 is at TDC at 0 degrees, #2 will be at TDC at 60 ABDC, and #3 at 120 ATDC. Think of it as a 720 degree rotation where 0 it's #1 TDC, 240is #2 TDC, 480 is #3 TDC, then repeat. To find cam timing for #3 on your #1 oriented wheel, add 480 degrees to the #1 timing. For our theoretical timing above that's
IVO 110 ATDC
IVC 30 BTDC
EVO 68 ABDC
EVC 48 BBDC

6: Do the math, write it down. Do it again, write it down, now do it again. It's very easy to screw up when thinking in circles like this and be off by 10 or 20 degrees.

7: Time #3 using your values, check it a couple times. Now go back to #1 TDC crank marks, ensure your wheel is still at 0 when marks are aligned, and visually LOOK at #1 cam lobes during the overlap period. Are both the exhaust and intake slightly cracked open as they should be with the cam lobes pointing towards throttle body for intake and pointed at the exhaust header for the exhaust cam?

Good, job done without having to fiddle with aligning the wheel 0 degree to the #3 cylinder TDC point, or installing a second pointer (one for #1 one for #3).

While it takes more math, I found it easier than doing the wheel adjustment method.

 

[Joesmoe]

I actually understand this last one.

 

[Claviger]

You asked what a small change can do? Here ya go, a small adjustment:

 

[Claviger]

Complete with mechanical part!! Need to wash it... oh god poor baby has oil, coolant, grime, dirt everywhere. No test ride today, it's pouring rain and testing out a new engine in the wet... pass.

If you listen closely you can hear the slight lope, even at 1100 RPM:

First press of button, crank, crank, fire. Exactly as God and Triumph intended. No throttle silliness required, no multiple attempts. Single battery. All the silliness that I had going on before is gone for starting. TBs perfectly synced at 660 during idle, the lope is very much from the cams hehe

 

[Kevin frazier]

Complete with mechanical part!! Need to wash it... oh god poor baby has oil, coolant, grime, dirt everywhere. No test ride today, it's pouring rain and testing out a new engine in the wet... pass.

If you listen closely you can hear the slight lope, even at 1100 RPM:

First press of button, crank, crank, fire. Exactly as God and Triumph intended. No throttle silliness required, no multiple attempts. Single battery. All the silliness that I had going on before is gone for starting. TBs perfectly synced at 660 during idle, the lope is very much from the cams hehe

Sounds awesome 750 800 rpm?

 

[Kevin frazier]

Man that don’t even sound like 1100 that is smooth

 

[Kevin frazier]

That thang sounds angry

 

[Starmanut]

Complete with mechanical part!! Need to wash it... oh god poor baby has oil, coolant, grime, dirt everywhere. No test ride today, it's pouring rain and testing out a new engine in the wet... pass.

If you listen closely you can hear the slight lope, even at 1100 RPM:

First press of button, crank, crank, fire. Exactly as God and Triumph intended. No throttle silliness required, no multiple attempts. Single battery. All the silliness that I had going on before is gone for starting. TBs perfectly synced at 660 during idle, the lope is very much from the cams hehe

Well, truthfully I did not understand much of the tech talk. But I do understand the sound, and that is sa-weet!!

 

[Claviger]

Sounds awesome 750 800 rpm?

I'm sure it's quite lopey, but I keep idle set at 1k to ensure oil pressure is solid. Once it's fully up to temp it floats are 970-1000, in the video it was still warming up.