I'm installing the cam chain on a 02 rsx type s (k20a2) and I set the crank at TDS (crank sprocket punch marked aligned with oil pump pointer), set the camshafts at TDC, and I get the chain on with the colored links on the punch marks on the cam sprocket and both cam gears.

Once I install the auto-tensioner it rotates the crank and knocks it off of alignment. I've tried several times and even offset the crank sprocket to compensate the movement but it is still off.

I calculated that the crank is off exactly 3.9 degree's. The head had .005" removed. My buddy who is a honda/acura master technician was here during the install and said it could possibly be attributed to chain stretch. I won't be able to work on this car until I get back from vacation so I thought I would ask you guys if there is anything I'm over-looking.

Have any of you guys ran into this problem before?

 

I'll post some pictures up later tonight.

 

Sprockets TDC with the dark links aligned with the punch marks:



Crank Sprocket TDC and aligned with oil pump marker (The dark link is on the crank sprocket punch mark, you cannot see this in the picture) :
(yes the auto-tensioner is installed in this picture, I am just using this as a reference picture so you guys get the point. I also see the punch is maybe 1/2 degree off, like I said... just a reference picture).


So once everything is TDC you remove the pin from the auto tensioner. The problem is the slack on the intake side of the chain allows the tensioner to rotate the crank sprocket clockwise, thus throwing it off about 1/2 tooth.

Crank sprocket off tdc once pin from auto tensioner is removed.


So then you rotate the engine clockwise and you will hear the auto-tensioner click, thus creating the tension to the chain. After a full rotation cycle and back at TDC the dark links will not line up like before. This is normal (length of chain in relation to the different diameter sprockets, I think we all understand that much).

So rotate the assembly to TDC according to the crank sprocket.
Camshaft sprocket position once rotated one full cycle when auto-tensioner is installed.


Crank Sprocket TDC once auto-tensioner is installed.



If you set the cam sprockets at TDC you end up with this at the crank:

 

Nobody?

 

i had a similar issue when i shaved the head on my miata. i retarded the intake cam. i don't know it that's possible with a vtec head, or if it's a good idea with an interference motor.

if you retarded the cams a 1/2 link before releasing the tensioner, wouldn't that align them properly?

what do the alignment marks look like after another full cycle?

 

I just swapped my new block in last week and had the same issue.

Heres is how I solved it. Took two people and a little time but take the chain and both tensioners completely off. Align the mark on the crank pulley first and then have somebody tilt the cams towards you w/ the marks aligned. Put the chain on w/ marks on the links (not in between) and lower the cams and hold them tight. Don't let them move, spin nothing. Then install both tensioners at the same time. Works every time.

I've seen many many cam installs and not one stretched chain that would cause this problem. Its definately an install issue, timing is very very hard to do by yourself. Good luck and post up if it works out.

 

After a full cycle the cams are tdc with another but at the crank it is off 3.9 degree's. If you rotate it counterclockwise to release the tension on the exhaust side of the chain it provides enough slack for the crank to be TDC as well as the Cam sprockets.

Wierd stuff... I just got a new chain and guides to see if this solves anything. I just wanted to ask you guys first. I found a good article on k20a.org but it doesn't give me a straight answer.

 

by reading your other thread in FI about the mazworks cams, i realize how incompetent you are.

you are not installing it right. take it to a professional that knows what they are doing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 05RSX &raquo;</TD></TR><TR><TD CLASS="quote">by reading your other thread in FI about the mazworks cams, i realize how incompetent you are.

you are not installing it right. take it to a professional that knows what they are doing.</TD></TR></TABLE>

LOL

I actually had a honda master tech here checking it out while I was doing the install. Not everyone knows everything and we all make mistakes... that's why we have a forum so we can all share information with each other. I know several people on k20a.org had the same exact problems.

I'm glad you seem to know everything. I find it also flattering that you follow all of my posts on this forum.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 05RSX &raquo;</TD></TR><TR><TD CLASS="quote">by reading your other thread in FI about the mazworks cams, i realize how incompetent you are.

you are not installing it right. take it to a professional that knows what they are doing.</TD></TR></TABLE>

You're completely worthless, aren't you?

He's trying to learn new stuff and you're sitting there in your ignorance not even trying to learn, just criticizing others because you don't know either.

 

sounds like your tensioner cannot compensate for the extra slack made by the lowered cams (shaved head).

let us know how it works out.

 

Turns out the guys bottom end was completely fubar'd and I ended up having to do a complete rebuild.

I'm throwing the timing chain on and it's still giving me the same issue. When the tensioner is released it knocks the crank sprocket over about 1/2 a tooth. The cams will stay at TDC though. You can reverse the crank manuall to compress the tensioner and it the sprocket will read on the dot again.

 

sent PM - i might have timing issues after cam install. did you ever figure this out

 

you can def cutt your hands pretty bad trying to get the timing right on after market cams.. i learned the hard way helping my friend on his..

 

Well guys I forgot to update this thread, but it turned out the motor was trashed. I was dealing with an extremely incompetant shop doing the head work (Head Games) and they managed to screw it up 3 times (valve-lash issue, improper guide installation, valves not seating, etc). I ended up pulling the motor to check the bottom end out and in fact it was trashed as well.

Anyways, I found out that the place who built the motor originally had removed a good bit of material from the block. I had the amount of material calculated and I in turn ordered a thicker head gasket to set everything back to 'stock' essentially. The headgasket did in turn help the '1/2 tooth off' problem a little bit, but the last picture will always be a little off because the tensioner is based on oil pressure. So if you guys realize that when you release the tensioner you are 1/4-1/2 a tooth off, you are ok. I even had a bone stock K20a2 motor that we did for another customer and I removed the valve cover and crank pulley to reference the TDC issue and in fact the crank pulley/gear was 1/4-1/2 a tooth off when the tensioner was released.

Anyways, the car ran great and made right at 350whp before our customer totaled the car.... such a shame considering we were going to throw on a Full-Race kit and go for around 500whp.

 

for future reference -

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by "Hondata" &raquo;</TD></TR><TR><TD CLASS="quote">At TDC the arrows on the cams (#1 of the exhaust, #4 on the intake) should be in alignment with the parting line on the cam cap (outlined in blue in the photo).



</TD></TR></TABLE>

here is some good info from talonxracer - for k20a motors

Set the crank at #1 TDC. As long as that is established, set the intake cam with the hash mark lined up with the cam cap parting line. Now it is most important to look at the timing chain and where it passes the front cover, the cover must bisect a link, otherwise you are one tooth off on the crank sprocket. As long as the chain is tight from the intake sprocket to the crank the intake is now set correctly. You must prevent the chain from dropping off the crank sprocket as you will have to start at the very beginning all over again.

here is a pic, notice the red arrow...

 

You can also use a 5 or 6mm punch to lock these TDC so when you put the chain on the gears don't move on you. That way you know the cams are TDC.