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Discussion Starter #1
I have a K24 which have been bored and stroked, and relevant to this port did the following upgrades:
- Added a Go-Power cam from Jeff.
- Having started with a TSX head, we machined the cam sprocket to advance to 40 degrees instead of the standard 20 degrees.
- Loaded heavier springs to deal with the wilder cam

This engine has a loud noice in the valve cover, and also wears the cam lobes very quickly. We have not been able to run the engine properly and there should have been minimal wear all over.

Regarding the noise we now established the following:
- If we load a standard cam, the noise is gone
- If lock the VTC sprocket the noise is gone (see photo below)
- Our chain does not jump as per the following thread http://www.k20a.org/forum/showthread.php?t=36364&highlight=vtc+gear+noise
- If we disconnect the VTC valve, the noise stays the same
- The noise is louder at idle, and completely goes away at around 2,000 rpm

Regarding the cams, we had it regrind, and nitrided it. After 5 start ups the lobes were worn again.


Video of the noise
http://www.youtube.com/watch?v=Uf_e3t6ipTo

Photo of the cam lobes after it was nitrided and after 5 start ups


How we locked the sprocket. See the socket in between the sections



We since replaced the timing chain and tensioner with new ones as we thought they are not working properly, no difference in noise. All parts have been checked many times and assembly has been done by different people now - so this can be ruled out. Valve clearances have been checked and the the valves also clear the pistons. Oil pressure is according to Jeff's specs and what we are used to (I run dry sump)

Can anybody help? please no uninformed guessing. I have had enough of that.
 

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What are the thoughts of you and your mates?
Do you have any idea what may be causing this?
What is the history of the engine block and head?
Over heated before? Oil type?
 

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Sounds like the probleme we got with the 5,4 in ford truck doing that kind of noise (I'm ford tech). The camgear always move and creat a knocking noise at low rpm in the valve cover. Did you check if the oil passage on the cam is clear of any thing can reduce oil flow trough the pulley with the go power cam.

If you loose any oil pressure going to the pulley they will do that kind of noise.
 

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Discussion Starter #5
What are the thoughts of you and your mates?
Do you have any idea what may be causing this?
What is the history of the engine block and head?
Over heated before? Oil type?
We are now keen to replace the cam gear as 1st step to sort out the noise. The engine seized one piston when it was put unde rpower whilse the engine was cold, but we since resleeved.

The head was purchased from Jeff - I do not know the history before that.
We use Castrol Edge Sport (synthetic)
 

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I'm confused why the noise would go away when you lock the cam gear?

The cam appears to be soft on that lobe, Honda even has problems with this!

When you put in stock cams did you keep the vtc wheel from the problem cam?
You mean I hould not be worried about the cam gear? Would it not be destroyed soon if it looks like this after a few start ups?

Yes we did keep the same cam gear all along. This gear also was in my previous "standard" K24 A2. That is why we did not suspect it to be the problem for a long time until we did this test.
 

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Sounds like the probleme we got with the 5,4 in ford truck doing that kind of noise (I'm ford tech). The camgear always move and creat a knocking noise at low rpm in the valve cover. Did you check if the oil passage on the cam is clear of any thing can reduce oil flow trough the pulley with the go power cam.

If you loose any oil pressure going to the pulley they will do that kind of noise.
When the cam was regrind and nitrided, it was properly cleaned to remove all the residue from the nitriding. I am comfortable with this.

Just in case it may cross your mind, we also checked the oil pressure in the head - this is also according to Jeff's specs.
 

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When the cam was regrind and nitrided, it was properly cleaned to remove all the residue from the nitriding. I am comfortable with this.

Just in case it may cross your mind, we also checked the oil pressure in the head - this is also according to Jeff's specs.
Great. And the cam gear seat well on the camshaft no loose there. Did you compare the size of the stock and go power cam on the end of the pulley?

If everything is fine there, I would say try another VTC cam gear.
 

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You need to contact Jeff at Go-Power about the cam wear. I know a few companies had issues with excessive cam wear due to improper heat-treating process. He will be able to help you out I'm sure.

Did you adjust the valves properly after the cam install?
 

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What is your oil pressure when you hear this noise and where did you locate your sender at on the head? What does Kpro show for VTC activity, both cam and camcmd at the tie of the sound?
 

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the problem is with the actual cam, not the cam gear. 02-03 civic si's are known for galling cams, when replaced with different ones it no longer happens....you need to get new cams
 

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I have seen this issue on stock cams. The mearing on the cam actually stops and doesnt care any damage or loss of power.

The noise you are hearing sounds like it is coming from the tensioner/chain. with the vtc gear, it allows to cause a little slack in the chain. look at the tensioner or what I would do is look at running single lobe and degree the motor for correct centerlines and your issue will be gone.
 

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Discussion Starter #13
You need to contact Jeff at Go-Power about the cam wear. I know a few companies had issues with excessive cam wear due to improper heat-treating process. He will be able to help you out I'm sure.

Did you adjust the valves properly after the cam install?
Answer to both is yes. I did contact Jeff, and we did adjust the valve clearance = 0.010"
 

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Discussion Starter #14
What is your oil pressure when you hear this noise and where did you locate your sender at on the head? What does Kpro show for VTC activity, both cam and camcmd at the tie of the sound?
Oil pressure at the VTEC is 0.8 bar

I do not use Hondata anymore. We do not have proper support for it here in SA, so I am using Gotech which is also used in the US on Kseries.

The sound is there whether we disconnect the VTC plug or not, so the VTC activation does not appear to cause the problem.
 

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I have seen this issue on stock cams. The mearing on the cam actually stops and doesnt care any damage or loss of power.

The noise you are hearing sounds like it is coming from the tensioner/chain. with the vtc gear, it allows to cause a little slack in the chain. look at the tensioner or what I would do is look at running single lobe and degree the motor for correct centerlines and your issue will be gone.
So you reckon the wearing will not get much worse?

I reckon your thoughts are in line with mine regarding the cam gear. It does allow some slack when it runs between the intake and exhaust lobes - we could see it if we turn the engine by hand. The noise does sound like the chain. We replaced the tensioner & chain already and found no difference.

What we do not understand, is why is there no noise when we lock the cam gear? is the cam gear allowing the slack, or is the tensioner allowing the slack?

If it is the cam gear, which it appears to be, then why does it allow movement? Is the spring in the plunger too soft, or what else?

Should I consider replacing the cam gear with a Type R gear or stick with a 20 degree standard gear?

Too many questions at once?

I appreciate your assistance guys.
 

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Id try a factory type r cam gear first, and see what you get... then go from there. Process of elimination.
 

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So you reckon the wearing will not get much worse?

I reckon your thoughts are in line with mine regarding the cam gear. It does allow some slack when it runs between the intake and exhaust lobes - we could see it if we turn the engine by hand. The noise does sound like the chain. We replaced the tensioner & chain already and found no difference.

What we do not understand, is why is there no noise when we lock the cam gear? is the cam gear allowing the slack, or is the tensioner allowing the slack?

If it is the cam gear, which it appears to be, then why does it allow movement? Is the spring in the plunger too soft, or what else?

Should I consider replacing the cam gear with a Type R gear or stick with a 20 degree standard gear?

Too many questions at once?

I appreciate your assistance guys.
If it is wearing, what makes you think it will stop? :confused:

So, the slack is in the chain correct? Like this?
http://www.youtube.com/watch?v=KdWk-CCKfuU

and with the OEM cams you do not have slack? (no noise as mentioned in first post)
http://www.youtube.com/watch?v=t3CqOPnKKoU
 

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If it was the gear wouldn't it do it with the stock cams?
missed this in the first post. Very interesting.

Bad ramp design? Jerk? Who knows... it could be a number of things and I wouldnt want to start pointing fingers. If cams fix the issue with all other variable staying constant, Id say you have your answer.
 

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If it is wearing, what makes you think it will stop? :confused:
I do not think it would stop, but responded on the message as quoted. This concerns me as the wear shows at an early stage.

So, the slack is in the chain correct? Like this?
http://www.youtube.com/watch?v=KdWk-CCKfuU
No not like this. It merely has a bit of slack which one can feel with your finger, but it does not slap the guide.

and with the OEM cams you do not have slack? (no noise as mentioned in first post)
http://www.youtube.com/watch?v=t3CqOPnKKoU
Correct
 
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