Cams are retarded. Roughly 2 degrees I'd bet. So def get that exhaust cam advanced.

With them retarded. You increase p2v on the intake but Dec on exhaust.

But if it was me what's spending an extra 400 bucks to get it exactly timed in and then you will know your exact clearances. It can be done with head on and engine in car

 

Yeah that makes sense now that I think about it.

I'm gonna leave it at 0,+2 since I know that won't hurt the engine for now and then get the degree kit to do it right. We have actually had the cams at -2,-2 and didn't have any P2V contact so I know it's ok but I agree degreeing them is the right way. I'll order the kit tonight.

 

Well like I said earlier I ran mine exactly as you have it but with stock cam gears. Itr cam shafts it ran good for 4K miles. Then one day Broke traction in 3rd smacked the limiter and bent exhaust valve. I do have flat top Pistons tho.

Good luck

 

I could be wrong on this


As you move away from tdc (btdc) you are advancing and as you get closer youre retarding timing

when tuning a motor and ign timing this is the way you word it.

Is this backwards for mech timing?

So if you pass tdc on your crank that one degree and your cams line up to me that would mean your cams are advanced and you need to retard them.

 

I'm guessing my dished pistons are the reason I haven't had issues. Engine has been just shy of 9k with no issues. Don't normally rev like that but it has happened on a few occasions.

 

The reason I was thinking the cams were retarded was due to where the cam gear TDC marks line up is after TDC, roughly 2 degrees ATDC.

The stock timing is 16 degrees BTDC if you go to 18 degrees BTDC you are advancing the timing. That's why I thought the cams are retarded, but maybe I'm making a wrong assumption here.

Also to get the cams to be a TDC at the same time as the crank I would need to add degrees (roughly 2 deegs) to both cams. Another reason why I figured they were retarded.

 

Is this the degree kit you guys are using?

Xenocron Tuning Solutions: Mike Belben BSeries VTEC Cam Degree COMPLETE Fixture Kit

Or is there a different/better one?

 

They are retarded trust me. The engine runs counter clockwise. The cams line up perfectly after tdc

That kit is good. I like the fcs race kit. But both are good

 

So its lined up perfectly on the gear but not the dampner. First thing I would do is try another dampner. The timing cover bolts are shouldered for a reason, so that your timing marks will be dead on. Why would you trust the dampner over the gear?

 

Just FYI, ALL of this already been stated before and at much more depth. The only way to fix is with a degree kit though, not randomly guessing.

For those that say you can't correct this issue with a timing belt tensioner, then you obviously have never used one before.

As you mill the head, you are shortening the distance between the centerlines of the crankshaft and camshafts. This makes the belt too long now on the exhaust to crank side of the timing system as there is no tensioner to compensate like on the other side... unless of course you add one. This side of the belt having slack retards the camshafts - think about it. So without adding anything, you are left with mismatched marks. This is where degreeing the cams comes in (which should be done on every engine build anyways as standard procedure).

So as I said before, you either buy the tesnioner to make the marks like up OR you just leave it as is and deal with the offset marks through degreeing. It really doesn't matter which way you chose.

OP - I have that degree kit, it's nice aside from the timing wheel.

 

I agree with full degreeing of the camshafts and assembly, but not with use of the tension to "solve all". It's not a flex issue here, you understand, of course, so there is still no need. But using the degree wheels from the mill/deck is the best option in this case, especially with the stronger belt.

 

Well it's not perfect but close enough has last 5 years and 25k-30k miles. I set the cam gears where I knew it was safe and left it alone.

I'm happy with the final result. Didn't get 400 ft/lb but what can you do. Here is the plot of the Mark I (old wheel) in red vs the Mark III (new wheel) in blue. Everything else is the same other than the switch from Buddy Club to Toda cam gears.




Video posted in in first post on first page.

As with all pulls on this engine this was done on pump 93.

 

I plan to get a degree wheel and figure out where the cams are but unless its 4 degrees off I probably won't mess with it.

As far as the crank mark and the oil pump mark the difference was due to the angle/perspective I was using. I put an OEM crank pulley on this engine and got the same result and the ATI damper on my engine on the stand that has never been opened up lined up perfect. The issue was/is the shaved head and decked block.

 

Its a little late but I would also trust the gear over any pulley as the pump has dowels and bolts (obd2 gear can't be flipped around like the obd1 due to the crank sensor spacer like points it has) I don't see the pump moving without causing a leak and the gear mark is definitely not going anywhere. I turn the wheel to the left and then remove the pulley. I then have a pretty straight look assuming I'm looking from the bottom driver fender at the gear and pump mark without having to remove the wheel(depending on size). I would not recommend it over a degree wheel but thats the best way i know of without one.

 

This setup would crush souls on E85

 

Yeah but I think I'm done with the car as far as looking for more performance goes. I daily drive it and I think going e85 would really impact the driveablity of it. Maybe I'm wrong but I was discussing it with my tuner and we both feel it would have an impact.

I'm more than happy with how it drives now and the power it makes and the way it's delivered. Car is really a blast to drive.

 

Congrats on really solid numbers!!

 

Solid numbers.

I would have expected to see faster spool though.

 

I'm betting that is down to the cam timing. If the cams had been degreed I'm sure spool time could have been improved. Especially as we would have been able to work on adjusting the cams gears. As it sits right now the intake cam is probably 2-2.5 degrees retarded and the exhaust cam is probably between 0-.5 degrees retarded.

I could see GSC cams offering up some nice gains in spool too if they were degreed. I'll use the degree kit when I get a chance and see how much things are off and then decided if I have enough safety margin or if I want move the cams and then put it back on the dyno to clean up the tune.

 

I just thought of something else too with the spool. I believe I had the S300 quick spool set up with the last pull on the Mark I but we didn't have it on yesterday. That was an oversight. You can see how the boost came in faster with the quick spool set up. I'm also using the MAC solenoid for boost control and I have read the GM solenoid is faster acting/better at control.

 

Hmm. that "quick spool" didn't seem to do much of anything from what I can see just from that particular graph on page 1. I've had those respond much faster with that boost pressure. But, that may be more timing as previously mentioned. I'd need to see a boost/rpm graph to confirm, however.

That IVS on the inlet makes that turbo a little quieter, huh?

 

It is quieter but I'll take power over sound. It seems to me like I hear the sound earlier though, if that makes sense. So it's louder right around the time positive pressure starts.

 

Way late on this but there was one other rather larger difference between the pulls. The old pull was with the E cutout open but the most recent pull was with the E cutout closed. Past experience tells me that makes a difference of about 10-15 hp but I am not sure what impact that has on spool but I know it has some impact.

I'm still working on getting the bbg dialed in right but I can tell you I had to drop a couple psi in 3rd to maintain traction and work on the solenoid duty cycle. That suggests to me Mark III is more efficient than Mark I.

 

So the wife and I had our cars out a few weeks back and took some pics in the fading light. Figured I would throw them up here.









The tyre marks are NOT from us lol

Still tweaking 3rd gear boost settings but car is running as hard as ever.

4th gear on the street is pretty damn scary lol

 

Needs moar low and wint tint.

Both