Okay so I have my timing situated for my 4g63 head on my 4g64 block (G4CS)

Everything is lined up how it is supposed to be with the larger timing belt and both gears advanced by half a tooth. Here is my question:

Because of the half a tooth difference, my dowel pins on the camshaft gears are not perfectly set at 12:00.

There are 48 teeth on each cam gear which mean that the distance from center to center on the teeth is equal to 7.5°.

Would it be proper to adjust the cam gears 3.75° on each camshaft to bring the dowel pins back to a perfect 12:00 position? See photo below:

Have you tried backing the crank 1 tooth?

TK's9d2TSi said:

Have you tried backing the crank 1 tooth?

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Hey not sure what you mean, I have all of the timing marks where I want them but the problem is the cams aren’t set at 12:00 when everything is at TDC

I just did this on my 4GCS, it’s hard to see in the pic but the white mark is my half tooth offset, with HKS 272s adjusted to cam card specs the intake is +2 and exhaust +4. I also have the OEM D64 cam gears and when testing between those and my Tomei’s with settings above was only off by +/- 1 degree for valve opening/closing.

Dashnizzle said:

Hey not sure what you mean, I have all of the timing marks where I want them but the problem is the cams aren’t set at 12:00 when everything is at TDC

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I think the cams aren’t lining up because you’re a tooth off on the crank. Not sure how else to explain it.

I take it you’re not using a cam lock tool?

blue90GSX said:

I just did this on my 4GCS, it’s hard to see in the pic but the white mark is my half tooth offset, with HKS 272s adjusted to cam card specs the intake is +2 and exhaust +4. I also have the OEM D64 cam gears and when testing between those and my Tomei’s with settings above was only off by +/- 1 degree for valve opening/closing.

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That's helpful! unfortunately with the HKS 280's i cant get the cam specs so I need a good starting point so that hopefully I can get it a bit more dialed in on the dyno....

So what you are saying is that these settings you have now put you close to where the stock '4g64' cam gears would have had the cams at +- a degree or so? Or am i not understanding?

Correct, when I was testing and comparing those settings on the adj cam gears along with the 1/2 tooth offset match where the stock 4g64 cam gears place the cams at in relation to the crankshaft (+/- 1), which coincidentally also match the HKS cam cards. This gauge setup definitely made it easy to check/verify everything.

That's the right tool for the job!!

I haven't thought this all through and haven't tried building a 4G64 DOHC hybrid but shouldn't the timing marks your lining up be the outer marks on the cam sprockets? In the OP picture shows the inner lining up. The inner ones on adjustable sprockets would move relative to the correct camshaft timing.

If you don't have a cam card can't you make your own by profiling the cam relative to the dowels?

steve said:

That's the right tool for the job!!

I haven't thought this all through and haven't tried building a 4G64 DOHC hybrid but shouldn't the timing marks your lining up be the outer marks on the cam sprockets? In the OP picture shows the inner lining up. The inner ones on adjustable sprockets would move relative to the correct camshaft timing.

If you don't have a cam card can't you make your own by profiling the cam relative to the dowels?

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Yes you are correct when I adjust the gears those marks will be off that I made with a marker. It would have made more sense to re-mark the actual outer cam gear (which is supposed to be ‘off’) if there’s a way I can set these cams where they are supposed to be without a cam card I’m all ears.

And yeah, Blue90gsx that’s an awesome tool you have!! The only thing I don’t quite understand is how both of your cam gears are advanced. I would think to get the dowel pins closer to straight up and down like on the 4g64 gears you would retard the gears (instead of advance like in your photo) to make up for the half a tooth 3.75° advancement on each. This is what someone else I talked to had on his G4CS that was built by boostin performance. The gears were slightly retarded just under the 4° mark, here’s the photo he sent me:

Dashnizzle said:

Yes you are correct when I adjust the gears those marks will be off that I made with a marker. It would have made more sense to re-mark the actual outer cam gear (which is supposed to be ‘off’) if there’s a way I can set these cams where they are supposed to be without a cam card I’m all ears.

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This may be what I don't understand, why are they "supposed to be ‘off’"?
I can understand the inner marks being off (that's how you adjust the cam timing) but not the outer marks that's the only way you know your belt hasn't jumped time down the road.

If you didn't have adjustable cam sprockets you might have to move a sprocket to get a cam in the right timing (like to correct for changes in deck height) but not with adjustable ones.

steve said:

This may be what I don't understand, why are they "supposed to be ‘off’"?
I can understand the inner marks being off (that's how you adjust the cam timing) but not the outer marks.

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The inner marks were made by me with a marker.

The actual white timing marks are half a tooth off each because since the 4g64 deck height is 6cm taller you can’t use the 4g63 timing marks anymore. The belt actually has an extra tooth when compared to the 4g63 belt so you have to compensate half a tooth each gear which basically led me to the purpose of this thread. With the half a tooth advanced on each gear I’m trying to see if I need to correct for that. By 3.75° on each cam gear. Follow me?

Here’s some info about this if you’re interested:
Click

On this topic I spent several weeks reading the forums, EVO, DSM and Galant. No surprise I came to realize a lot of misleading info out there.

The link you posted is solid, the problem as you stated is the crank TDC mark and 4g63 cam gear timing marks will never line up when doing a timing belt job on a 4g64/4gcs/DOHC combo. When you offset by the half tooth and remark, it consistently will. During the process of trying to get my head wrapped around why my numbers were different, I swapped between D63, D64 and tomei several times.

BL, adj cam gears were marked for the 4g63 (outer timing marks) and need to be offset the half tooth and remarked if using on a 4g64/4gcs. The cam gears will also need to be degreed no matter what. The half tooth gets it them close but not perfect.

FWIW, my cam degree numbers didn’t match anything I read on the internet either, which is not unusual somehow I am always the anomaly. My notes attached.

blue90GSX said:

On this topic I spent several weeks reading the forums, EVO, DSM and Galant. No surprise I came to realize a lot of misleading info out there.

The link you posted is solid, the problem as you stated is the crank TDC mark and 4g63 cam gear timing marks will never line up when doing a timing belt job on a 4g64/4gcs/DOHC combo. When you offset by the half tooth and remark, it consistently will. During the process of trying to get my head wrapped around why my numbers were different, I swapped between D63, D64 and tomei several times.

BL, adj cam gears were marked for the 4g63 (outer timing marks) and need to be offset the half tooth and remarked if using on a 4g64/4gcs. The cam gears will also need to be degreed no matter what. The half tooth gets it them close but not perfect.

FWIW, my cam degree numbers didn’t match anything I read on the internet either, which is not unusual somehow I am always the anomaly. My notes attached.

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Well the proof is in the pudding I suppose. That’s pretty crazy that the stock 64 gears put you basically there without needing the tomei’s. I admire your attention to detail on this.

I still can’t wrap my head around how you needed to advance your Tomei gears rather than retard them to get basically the same numbers as the 64’s. I would think that when using the 64 gears you would essentially have -3.75° on each by default because the dowel pins are straight up and down when the timing marks match.

Not sure if that makes sense but at this point I’m stuck between dropping my Hks 280’s altogether so I can find something that I can actually degree with specs (I emailed Hks they don’t know their specs either) OR using them and finding a good baseline that can be enhanced with some dyno tests.

By the way on another note I learned a lot about HKS cams in my research. The 264, 272 and 280 all have the same max lift only the duration was changed between the 3. Can I use this information to get close? Here is my other thread I posted on this topic that came to no new conclusions: HKS 280 thread click me

Dashnizzle said:

The only thing I don’t quite understand is how both of your cam gears are advanced. I would think to get the dowel pins closer to straight up and down like on the 4g64 gears you would retard the gears (instead of advance like in your photo) to make up for the half a tooth 3.75° advancement on each. This is what someone else I talked to had on his G4CS that was built by boostin performance. The gears were slightly retarded just under the 4° mark, here’s the photo he sent me:

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Click to expand...

blue90GSX said:

The link you posted is solid, the problem as you stated is the crank TDC mark and 4g63 cam gear timing marks will never line up when doing a timing belt job on a 4g64/4gcs/DOHC combo. When you offset by the half tooth and remark, it consistently will. During the process of trying to get my head wrapped around why my numbers were different, I swapped between D63, D64 and tomei several times.

BL, adj cam gears were marked for the 4g63 (outer timing marks) and need to be offset the half tooth and remarked if using on a 4g64/4gcs. The cam gears will also need to be degreed no matter what. The half tooth gets it them close but not perfect.

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Totally no offense and I am sorry if I am wrong, but I think you guys are confused and misunderstanding.
Basically you are gimmicking 4g64 cam gear by using "4g63" adjustable gears. What you really have to set is the dowel pin position on center hub, not setting a new horizontal timing mark with white line. That new white line position is not that important if it's within the adjustable range of cam gears.
You are still using 4g63 cam gear which has the dowel pin hole at 12 o'clock against the "4g63" horizontal timing mark. And now you have the horizontal timing mark half a tooth off with new white line which means you still have the valve timing approxi half a tooth off. (You are here now @Dashnizzle )
So,
If you make the horizontal timing mark by retarding half a tooth on both in/ex cam (like your and @blue90GSX pic), you need to advance valve timing by approxi half a tooth.
If you make the horizontal timing mark by advancing half a tooth on both in/ex cam (like the pic with AEM gear that you uploaded), you need to retard valve timing by approxi half a tooth.
If you make the horizontal timing mark by retarding half a tooth on intake cam and advancing half a tooth on exhaust cam, you need to advance valve timing by approxi half a tooth on intake cam and retarding approxi half a tooth on exhaust cam, and also vice versa.
All of examples above have the same valve timing and should be almost the stock position (Zero degree position). And this is probably the answer for your post #9.
If you have a method to degree cams, just degree cams from here. Probably it would be less complicated.

Dashnizzle said:

The actual white timing marks are half a tooth off each because since the 4g64 deck height is 6cm taller you can’t use the 4g63 timing marks anymore.

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The height difference is 6mm, Not 6cm.

Dashnizzle said:

I would think that when using the 64 gears you would essentially have -3.75°

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Half a tooth (3.75°) is approximate number.
Logically the valve timing difference should be nearly equal to 4.75° (as assuming the block/head have never been resurfaced and using the same thickness gasket as the stock). The cam gear diameter is approxi 145mm. When the cam gears move 1°, the belt would move nearly equal to 1.264mm. The distance difference between 63 and 64 is 6mm, so the difference in degree at cam should be nearly equal to 4.75°.

A bit off topic but I just can't see a head gasket between head/block in the pics above... Optical illusion or actually it was done with no gasket?

I went out to the garage and got a picture to shed some light on this discussion. This is why cam gears are remarked when timing a 4g64. The top gear is a 63 gear and the lower gear is a 64 gear. Both are from the exhaust side. Notice one has the timing mark on the tooth and one timing mark is in the valley between teeth? The picture he shared of the aem cam gears advanced 3.5 degrees above is after the cams were degreed in by boostin.

DSMPT said:

Totally no offense and I am sorry if I am wrong, but I think you guys are confused and misunderstanding.
Basically you are gimmicking 4g64 cam gear by using "4g63" adjustable gears. What you really have to set is the dowel pin position on center hub, not setting a new horizontal timing mark with white line. That new white line position is not that important if it's within the adjustable range of cam gears.
You are still using 4g63 cam gear which has the dowel pin hole at 12 o'clock against the "4g63" horizontal timing mark. And now you have the horizontal timing mark half a tooth off with new white line which means you still have the valve timing approxi half a tooth off. (You are here now @Dashnizzle )

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Yes this is exactly why I started this thread, We are replicating the 4g64 marks with 4g63 gears and need to correct for this. Thank you for the information by the way!!

DSMPT said:

If you make the horizontal timing mark by retarding half a tooth on both in/ex cam (like your and@blue90GSX pic), you need to advance valve timing by approxi half a tooth.

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Go easy on me if I'm wrong but didn't we advance each gear by half a tooth? If I have this wrong then there is the root of my misunderstanding. To re-center the dowel pins at 12:00 it appears to me that I need to retard my adjustable cam gears. This part is critical for me since I do not have any information / cam cards for the HKS 280/280 and need something that will work well enough for engine startup and break-in. OR get new cams that I can degree. This is my conundrum.

DSMPT said:

The height difference is 6mm, Not 6cm.

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Yep my mistake.

DSMPT said:

Half a tooth (3.75°) is approximate number.
Logically the valve timing difference should be nearly equal to 4.75° (as assuming the block/head have never been resurfaced and using the same thickness gasket as the stock). The cam gear diameter is approxi 145mm. When the cam gears move 1°, the belt would move nearly equal to 1.264mm. The distance difference between 63 and 64 is 6mm, so the difference in degree at cam should be nearly equal to 4.75°.

A bit off topic but I just can't see a head gasket between head/block in the pics above... Optical illusion or actually it was done with no gasket?

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6mm/1.264mm per degree =~4.75 makes sense ok.
Block and head both resurfaced (within service limits) and using Cometic MLS head gasket which is installed but not visible.

Just to be totally clear i will need to adjust roughly 4.75 degrees on each cam to bring it back to the stock location.

Dashnizzle said:

This part is critical for me since I do not have any information / cam cards for the HKS 280/280 and need something that will work well enough for engine startup and break-in

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Dashnizzle said:

Go easy on me if I'm wrong but didn't we advance each gear by half a tooth? If I have this wrong then there is the root of my misunderstanding. To re-center the dowel pins at 12:00 it appears to me that I need to retard my adjustable cam gears.

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In your case, in the pic below, the green line is supposed to be the 4g64 mark that you should set. (The blue line is the original 4g63 timing marks).
Now you have the green horizontal line set, but the vertical line you have is still blue for 4g63, so loosen the nuts/bolts on the gear and rotate the center hub to set the degree line to the green vertical line's position (advance approxi half a tooth). And then tighten the nuts/bolts to hold the position. This should make it close to the zero position, like you install the cams with the 4g64 stock cam gears.


Maybe I made you confused more in the last post.
Here is another way to say :
- You are supposed to advance the both cams by approxi half a tooth, because you have set the 4g64 horizontal line by having both cams (Or the 4g63 horizontal line) retarded by half a tooth. It should be like the 1st pic of 3 pics below. (This is your case).
- You were supposed to retard the both cams by approxi half a tooth, if you had set the 4g64 horizontal line by having both cams (Or the 4g63 horizontal line) advanced by half a tooth. It should be like the 2nd pic of 3 pics below. I guess this is the case of the pic with AEM gears you uploaded.
This is what I meant in the last post. All of 3 pics below would have the same timing.

So, if you advance or retard cams by rotating gear center hub would depend where you mark the 4g64 horizontal line.

This may go down as the best thread out there for timing on a 2.4L! I think I got it from here.


@DSMPT thanks for putting all of that together very helpful

In case anyone was wondering, here is what I did.

I took a punch and re-marked the new timing marks on the outer timing gears when they were where I wanted them.

Then I took a marker and made a mark where the old 4g63 timing marks were on the adjustable gear. These marker spots were now half a tooth off each.

I adjusted the timing gears until the new marker spots lined up with the punch marks I made on the outer gear.

At the end of the day here is where the timing lined up to put me back into ‘stock’ placement of the camshafts ~ -2.5ish° and -3.75ish°