TEC cam and fueling

niektoniekde

niektoniekde

Active Member
Hello guys. I bought TEC cam some time ago (1-1.5yrs) and I installed it just recently. Before I did my research on any available results and almost everyone had only praise for this modification.

I checked now and for my surprise I got a lot of informations that my engine is now probably running too hot and lean. Mainly because new cam increases air flow but that doesn't impact fueling as LS410 has narrow band O2 sensor and primitive ECU with lean map.

I have stock air filter, catalytic converter and exhaust and I don't want to change that now or in the future.
Is my AFR really that messed up after installing the cam? If yes, what are my options now?

I want to run the engine in normal temperature ranges and I also want it to be reliable and long lasting.
 
No it is not. We have sold a lot of our ht-b cam with a similar if not more aggressive profile and none had any problems. you can however install a cheap oil thermometer like I did on all of my big bore Himas -its 7 bucks from ali express and gives you peace of mind. I do get overheating if temperatures go above 40C and oil then hits 120C in city traffic. good idea to take a coffee break then. The other option is to get the fuelx pro which allows additional fuel in 7 steps to be added. it can ruin your average though.
 
Thanks for your quick reply. I'll buy the thermometer for sure.

Yea I checked the FuelX products but I don't like they are mostly workarounds working on closed-loop only.

BTW what's the best way to check valve clearances with TEC cam?

When I checked inspection without while engine was aligned to TDC "T" mark, I felt slight preload on exhaust valve. AI (Gemini) recommended to me that I should check clearance on closed valve while other is fully open.

Does RE updated recommendation on clerances apply to after-market/performance cams too? (0.08-0.10mm in; 0.18-0.20mm ex)
 
FuelX though it only works in close loop does utilized the fact that modern ECUs remember settings and if in close loop a certain additional fuel is applied over time the ECU will apply it througout operations.
I am not aware of a different method to check clearance with a modified cam.
I am also not aware of changed protocols re: RE. however, I ride a scram 440 and the head is different.
 
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LS410 has no cam timing adjustment unlike all the other New Engines from RE
You will almost never get correct alignment without an adjustable cam sprocket.
Set your valve clearances by ensuring the cam in is the right position, it does not have to be correct according to the Crankshaft, just be sure the valve is at rest, rotate the engine until you feel that period where the rocker is on the back of the Cam lobe.
High lift Cam will be noisy, I set my tappets tight at 3 and 7 thou.
 
Thanks. I'll do this soon. 7 thou that's ~0.18mm.. Isn't it too tight? I find it contradictory to previous information (3 thou; 9 thou)... What experience do you have with your clearances settings?
 
Unless the valves are still settling in to the seats the clearance will only increase.
Most times a high lift Cam is fitted the owner notices the tappet noise, some more than others.
You should be able to hear them cold and not hot.
 
I hear them more when engine is hot. But this was also the case before I installed cam. Mainly after highway ride.

When engine is cold, it's relatively quiet and tappet noise (metallic clicking) is almost gentle.
 
These valves have a tendency to dish on the Tip, due to the tappet screws limited contact area which gets worse with a high lift Cam, you may need to look at the turn method to adjust the clearance.
 
checking the tappet with a feeler gauge might be misleading on the LS410.

As @Dool pointed out the upper part of the valve tends to dish out. With the feeler gauge you won't measure the concave section made by wear, so what happens is that you measure 7 thou but in reality it might be much more.

I remember once I noticed this issue I started measuring tappet with a comparator and I found that when I thought I was right on spot I was actually off by 3-5 thou...
It tends to happen more on the exhaust valve.

If you want to be sure, remove cam and rockers and "feel" the tip of the valve with your finger, if it's dished out the feeler gauge is useless and you need some other method to adjust tappets...
 
niektoniekde said:
So what other method do you recommend then?
Click to expand...
On the LS410 I'd swear by a comparator, the most accurate way you can do it.

Set it up so that it touches the uppermost part of the adjustment screw (verify it is a positive contact) and move by hand the rocker up and down to see how the dial moves...
 
I ordered dial indicator and I'll try it that way later.

Today I set clearances with steps as follows:
* I rotated engine to TDC mark and checked if both rockers had free play, they did
* I checked clearances, ~0.13mm on intake, ~0.20mm on exhaust
* I set 0.10mm for intake and 0.23mm for exhaust

I did it with feeler gauges but I ensured they are past contact point and then I tightened the play (I set the clearance). Afterwards I dragged the feeler gauge away ensuring there is noticeable drag but not in forceful way.

After I started the engine, everything sounded relatively nice. Clicking/ticking noise was really gentle, maybe comparable to sewing machine. Anyway my hope disappeared quickly as engine warmed a bit (about 8-10min on idle) and I heard loud clicking but also some weird circular/rotational metallic sound? Now I genuinely don't know what to think about it.

I attached two recordings, the 01 is recorded around 1m away from engine where weird sound is most noticeable. Recording 04 is close to engine, maybe around 30cm or so. Both recordings were taken on clutch lever side of the engine.
 

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niektoniekde said:
Thanks for your quick reply. I'll buy the thermometer for sure.
Click to expand...
here is a pic, they are under 10 bucks at aliexpress. I had to make the casing for it though. Surprisingly resillient they are now 6 years old and still work, come with sensor too. You have to drill a threat into the oil sump bold on the left side to attach it.
 

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