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Engine Specific Info and Questions => IDI Engine => Topic started by: DVST8R on April 14, 2005, 11:47:45 pm
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Well here is a topic that I am sure there will be some debate. I for one no very little about camshaft design so this is for me and others like me to learn from. It has been expressed a many times, and a few times recently that the stock cam, isn't good for high rpm application, nor is it even good for making max power in the non modified rpm band.
With this being said I am sure that it wont be long till I blow the HG or get my twin fab finished, at which time I am either going to port the 1.6 head, or find a 1.9 head and port it, while the head is off I will oring the head and possibly the block, and goto either the 1.9 metal HG or a custom copper one, as well as studs. I will also look into porting the precombustion chambers and have some piston work done to drop the CR the "right" way. To bring this back on topic since the head will be off I want to have the cam either re-ground to the best that it can be, or replaced. So please discuss, and help enlighten the cam challanged :P
The few things that I know are lift determines how far the valve opens, duration is how long it is open for, overlap is the time that both valves are open, or if its negitive how long there both closed.
I have heard that more overlap will produce more power and help the turbo spool quicker, but I don't "know" this, but fuel economy will be the price which for me is fine, but some will care.
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Ok, I guess I'll go since I was the nay sayer in the other thread.
I haven't been able to find the diesel cam specs but I've heard duration was in the negative. From everything I know about camshaft profiles it seems virtually impossible to make a camshaft that flows well on the top end and is free from overlap.
First I'll start out by taking a look at the stock vw gas camshafts.
Solid lifter
Stock 1.6 - .406 lift 230* duration 10* overlap 110 lobe center
Stock 1.8 (JH) - .369 lift 212 duration 110 lobe center
G grind - .423 lift 235* intake duration, 234* exhaust duration - 16.5* overlap 109 lobe center
Schrick 272 .432 lift 272* duration 52* overlap 110 lobe center
The stock 1.6 cam is ok, but nothing amazing. As you can see they dumbed down the 1.8 cam for emissions. As a result that engine falls flat at about 5500 rpm. I know this from great experience. I had one of those in stock form once upon a time. Power specs - 90hp@5500 rpm
The G-grind is the european Heron 1.6 cam and is a popular upgrade. It allows the gas engine to make power up a little over 6k (btw, the Heron 1.6 had bigger valves than the regular 1.6). If you move up to something like the Schrick 272 you start running into the issue of port size. The stock 1.8 ports are too small and flow will become the limiting factor before you run out of camshaft. In a ported head the 272 should make power up to around your 7k rpm goal.
Hydraulic lifter
1985 GTI - .401/.402 lift 221* intake duration, 224* exhaust duration 2.75* overlap 109 lobe center
Schrick 272 .449 lift 272* intake duration 268* exhaust duration 50* overlap 111 lobe center
Stock G60 - unknown lift 220* duration 0* overlap 110 lobe center
The 85 GTI was no speed demon. It's stock power output was 100hp@5500 rpm. Once again, the 272 would probably make it to about 7k rpm. Notice the stock G-60 cam has zero overlap. For any of you who are not familiar with forced induction, this is common. When you have overlap you'll find that boost pressure will push right through the intake valves and out the exhaust valves which is bad for cylinder filling and at the very least increases the boost threshold.
Now, what does that mean? Well, if the 85 GTI had .2 liters more displacement and a more aggressive camshaft but made peak power at 5500, what does that mean for the 1.6? I can draw the following conclusions:
-The 1.6 diesel camshaft is of significantly less duration. This means that there is no time for proper cylinder filling at high rpm.
- The 1.6 diesel ports are smaller. Airflow will thus be hindered at a lower rpm if all else remains equal
- The 1.6 diesel valves are smaller. This will also hinder flow at high rpm.
Some other notes on custom camshafts: I would raise the question whether or not you can actually increase the duration of the camshaft. Tolerances in diesel engines are so close that I'm not sure there is a long enough "window" for the valves to be open for duration to be increased without possible piston to valve contact. I'm not saying it can't happen, but this is something that concerns me. Even so, you may stand to gain a couple hundred rpm worth of useable power before the bottleneck in the system moves elsewhere (ports, valves). Some of you (Jake) may find this useful as to be as competetive as possible within your racing class. Otherwise, I can't see this being a worthy investment.
For me, I'll stick with improving upon what the diesel does best - make torque and get good mileage.
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One question, remember I'm no mechanic. There isn't any overlap in the 1.6 diesel is there? If there was wouldn't it help in the area of producing vacuum? Remember I'm no mechanic but due to the nature of the this diesel that is why we have to run a vacuum pump, right? I agree on the part of no over lap due to valve to piston clearence. In my mind and experience, (valve to piston contact with minimal timing slip) there really isn't much room at all, zip nadda nill!!!
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Overlap isn't particularly good for turbos, not even on the gassers. On the diesels, it's nearly impossible to get overlap. With stock pistons and head gasket, it is impossible to get overlap.
Overlap also relies on a tuned header to create some scavenging vacuum at the exhaust port and in the cylinder to start drawing intake charge in. So wituot a tuned header, it's pretty useless. And you would need a header tuned to 4000 RPM's or so to use any overlap on a nomally asthmatic diesel to any advantage. That would mean that you would be making your own header from tubing from scratch, because none of the headers available for these engines will be tuned to that low an RPM range. Also, with only 18cc of volume above the piston, there's not much chance of "storing" vacuum from the header tuning even with no overlap or negative overlap.
With the turbo, the benefits of overlap pretty much go away. First, you don't have the tuned header scavenging effects, because there's a turbo on a standard manifold. And you also have boost in the intake which will blow through the exhaust valve and that wastes any benefit from the overlap.
With lift and duration, there are some very rigid limits in the diesel as well. The intake valve opening profile and the exhaust valve closing profile have to be pretty close to the stock cam. You can add duration on the closing of the intake valve and the opening of the intake valve (by widening the lobe center angle), but there's some limits to that as well. Also, more duration gives you a higher optimunm RPM range, and you can get beyond what the diesel engines can reach if you go crazy on duration.
One thing you might consider is machining the piston crowns for enough clearance for the "J grind" (049J markings) cam from a 1.7L or JH 1.8L solid lifter engine. That cam has about half the negative overlap of the diesel cams, and it has more duration than the stock diesel cam. FWIW, the last time I changed the timing belt, I actually tried to put a J cam in. It clunked when the valve(s) hit the piston(s) after maybe 10 to 15 degrees of crank rotation.
If you want to have something custom ground, more lift in the center of the cam lobe will definitely help, but the whole piston/valve geometry limits you in the first half of the opening profile on the intake and the last half of the closing profile on the exhaust. A cam that makes the valves go "CRUNCH!" won't make much power.
Finally, porting and polishing the port passages in the head is a great idea. The stock ports aren't the best for flow. And with a diesel, polishing the entire intake runner in the manifold and the port in the head to a mirror finish is a good idea. Matching the head and manifold at the intake manifold gasket also helps out a lot. You don't need any turbulence in the intake air in the diesel to mix the fuel mixture. It's not like a gasser in that respect. Polishing everything is good. On the normally asthmatic engines, you want to be careful about going too big on the ports and reducing the velocity and momentum of the airflow. But on a turbo, I would think that bigger would be better.
Bigger valves would also help. I haven't looked at the whole geometry of the diesel heads. I'm not sure if you could fit the 40mm/33mm combination from the JH head in there. If those valves can fit, that would help too.
I wouldn't do any porting in the pre-combustion chamber unless you really know what you are doing or you have a large pile of diesel heads to experiment with. I'm pretty sure there's not much to be gained there, and a whole lot to lose.
And you don't want to lower compression much. If you add even 3cc's of volume above the piston, you'll be lowering the compression below 20:1, and starts will get very difficult, especially in cold weather. You're starting out on the really steep part of the volume/compression curve, so a little more volume drops compression a whole lot at first.
Here's a "chart" of volume above the piston vs. compression ratio:
cc above piston | compression ratio
18 | 23:1
*********************************************************************
18.5 | 22.4054054054054:1
*******************************************************************
19 | 21.8421052631579:1
*****************************************************************
19.5 | 21.3076923076923:1
***************************************************************
20 | 20.8:1
**************************************************************
20.5 | 20.3170731707317:1
************************************************************
21 | 19.8571428571429:1
***********************************************************
21.5 | 19.4186046511628:1
**********************************************************
22 | 19:1
*********************************************************
22.5 | 18.6:1
*******************************************************
23 | 18.2173913043478:1
******************************************************
23.5 | 17.8510638297872:1
*****************************************************
24 | 17.5:1
****************************************************
24.5 | 17.1632653061224:1
***************************************************
25 | 16.84:1
**************************************************
25.5 | 16.5294117647059:1
*************************************************
26 | 16.2307692307692:1
************************************************
26.5 | 15.9433962264151:1
***********************************************
27 | 15.6666666666667:1
***********************************************
27.5 | 15.4:1
**********************************************
28 | 15.1428571428571:1
*********************************************
28.5 | 14.8947368421053:1
********************************************
29 | 14.6551724137931:1
*******************************************
29.5 | 14.4237288135593:1
*******************************************
30 | 14.2:1
******************************************
Oh, and vwmikes cam specs leave out the lift spec where duration was measure. And the measurements he gave are different on different cams. For example, the numbers he gave for the 1.6L gas cam and the "G grind" are total duration, where the duration he specified for the JH cam is at 0.050". The JH cam is about 10 degrees shorter in duration than the 1.6L gas cam, and about 15 degrees shorter than the G grind if you compare duration at the same lift on all the cams. IE, if you go at 0.050" on all of them, they would be somewhere around 212 degrees for the J, 222 degrees for the 1.6L cam and 227 degrees for the G grind.
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19.5 | 21.3076923076923:1
***************************************************************
20 | 20.8:1
**************************************************************
20.5 | 20.3170731707317:1
************************************************************
21 | 19.8571428571429:1
***********************************************************
21.5 | 19.4186046511628:1
**********************************************************
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:mrgreen: Ah but have you got any numbers to back this up? :mrgreen:
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Oh, and vwmikes cam specs leave out the lift spec where duration was measure. And the measurements he gave are different on different cams. For example, the numbers he gave for the 1.6L gas cam and the "G grind" are total duration, where the duration he specified for the JH cam is at 0.050". The JH cam is about 10 degrees shorter in duration than the 1.6L gas cam, and about 15 degrees shorter than the G grind if you compare duration at the same lift on all the cams. IE, if you go at 0.050" on all of them, they would be somewhere around 212 degrees for the J, 222 degrees for the 1.6L cam and 227 degrees for the G grind.
Sorry, look how late last night that was posted :D
Even so, I thought it still proved my point about peak power vx camshaft profile.
Take a look at this cam chart if you want more numbers.
http://www.techtonicstuning.com/cams.asp
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In my mind and experience, (valve to piston contact with minimal timing slip) there really isn't much room at all, zip nadda nill!!!
you are right there. Almost nothing at all. Worse on the 1.6 than on the 1.9. If the timing belt on the 1.6 is on a tooth off, you need a new cylinder head.
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Most interesting info and a great discussion...thanks!
Mike, I missed your "naysayer" post on the other thread, but I don't understand why you think cams can't help the performance of a diesel, or is that not what you meant?
On the old forum there is a thread where a guy from the UK talks about fitting a solid lifter (83-84 JH?) GTI cam to his 1.6TD. He was so impressed with the increased performance that he had Piper Cams grind him a custom version that is even better. Looking at the table on the link I am guessing that there is little or no overlap with a solid GTI cam, but with its greater duration and (maybe) lift it can flow more air at higher RPMs. I can't access that forum from work, but will try to find it later if someone doesn't beat me to it. :mrgreen:
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Most interesting info and a great discussion...thanks!
Mike, I missed your "naysayer" post on the other thread, but I don't understand why you think cams can't help the performance of a diesel, or is that not what you meant?
On the old forum there is a thread where a guy from the UK talks about fitting a solid lifter (83-84 JH?) GTI cam to his 1.6TD. He was so impressed with the increased performance that he had Piper Cams grind him a custom version that is even better. Looking at the table on the link I am guessing that there is little or no overlap with a solid GTI cam, but with its greater duration and (maybe) lift it can flow more air at higher RPMs. I can't access that forum from work, but will try to find it later if someone doesn't beat me to it. :mrgreen:
I wasn't saying a cam wouldn't help the diesel. I was saying that the stock cam is not very well suited for high rpm power and due to the closer tolerances it seems less than likely that a huge change in camshaft profile would be possible. I don't doubt there would be gains but I would be willing to bet the gains would be from about 4500-5500 rpm. peak power at 7k still seems unrealistic to me.
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and to throw a monkey wrench into everything...
last summer, I had a stock internal'd 1.6 hydraulic engine turning 6400, and a modded internal'd 1.6l turning 7000+ all with stock vw diesel cams. the 6400 engine (i'm sure it could have gone further, and probably did on more than one occasion when i was autocrossing not watching the tach) was still pulling hard at that point, but generally was put in the next gear for the simple reason of not particularly wanting to grenade my daily driver. (which happened for other reasons anyway :roll: )
the modded engine ended up with 17.5:1 compression and generally sucked at any rpm, though it approached ok-ness (another one of my new words) over 25 psi and 3500 rpm. Anyway, that engine was generally a disappointment but proved to me that a diesel was perfectly capable and very willing to rev to unheard-of levels.
If the current 1.9L project engine 'puts out' for me the way i'm hoping, then I'm not going to bother with another super high rpm 1.6L, as I love the low end grunt of the 1.9L. If not, then I'll try again with a 1.6 revver engine that has a decent compression ratio.
Incidentally, after 600km of 35psi there was evidence of combustion gas leakage between cyls 1&2 and 3&4. This was with raceware studs, and a fibre-type 1.6L head gasket. Not sure if a 1.9L steel gasket would have made any difference.
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Do you have any dyno charts? I'd really like to see how the power curve was shaping up.
Does the 1.9 gasket fit well on the 1.6? I would imagine the larger bore of the gasket would drop compression slightly.
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Actually, I'm not surprised at all!
Most of what we "know" is what we've learned from fuel-governed diesel engines and normally aspirated engines - particularly gas engines. But a diesel is not only unthrottled, which permits a full gulp of air to much higher RPMs than the same cam would permit on a gasser, but is TD'd as well. Compressed air is quite eager to enter the cylinder when the valve does open - just pull the valve out of a tire at 15 or 20 psi if you need to be reminded how eager cpmpressed air is to escape... ;)
From then on it's just a matter of adding fuel to reach higher RPMs. No magic cam is really needed. 8)
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Do you have any dyno charts? I'd really like to see how the power curve was shaping up.
sadly, no. I heaved that engine due to it's low compression ratio. I was looking at G's for handling purposes at that time though, and didn't see any rapid fall-off of acceleration at any point up to were i shifted.
the other thing is the chassis dyno around here needs a tach signal to operate. working on a solution for that too.
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Most interesting info and a great discussion...thanks!
Mike, I missed your "naysayer" post on the other thread, but I don't understand why you think cams can't help the performance of a diesel, or is that not what you meant?
On the old forum there is a thread where a guy from the UK talks about fitting a solid lifter (83-84 JH?) GTI cam to his 1.6TD. He was so impressed with the increased performance that he had Piper Cams grind him a custom version that is even better. Looking at the table on the link I am guessing that there is little or no overlap with a solid GTI cam, but with its greater duration and (maybe) lift it can flow more air at higher RPMs. I can't access that forum from work, but will try to find it later if someone doesn't beat me to it. :mrgreen:
Sorry, I'm not believing it. I tried a J cam (solid lifter from a JH engine) in my diesel head once. Valves hit pistons when I turned the crank by hand. Unless this guy machined something for more clearance, there's no way he actually ran the engine with a 049J cam installed.
IIRC, The J cam (vw part number 049 109 101J) has about 7 degrees with both valves closed. The diesel cam has around 11 degees with both valves closed. The J cam has 0.369" of lift (both intake and exhaust), and the diesel has 0.315" of lift on the intake valves and 0.354" of lift on the exhaust valves. Intake valve clearance is the big limiting factor. On the diesel with the stock cam, the valves come within 0.2mm to 0.3mm (0.008"-0.012") of the piston.
You might be able to grind the diesel intake opening profile and exhaust closing profile onto the J cam and get something that works and delivers better performance than the stock diesel cam. You might also be able to cut some valve relief into the pistons for valve clearance, but again, you would have to be careful not to remove any moer than necessary for valve clearance, and that might lower compression more than you want (see chart above).
The J cam does have enough duration to run optimum volumetric efficiency somewhere around 4500-5000 RPM's. For duration, it's just about right for the diesel engines. The problem is valve to piston clearance with that cam installed.
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On the old forum there is a thread where a guy from the UK talks about fitting a solid lifter (83-84 JH?) GTI cam to his 1.6TD. He was so impressed with the increased performance that he had Piper Cams grind him a custom version that is even better.
You're thinking of Simon Cooper, TDIRS. He was using a gas cam in his TDI but it required clearancing of the head so the cam lobes didn't interfere and cutouts in the piston tops for valve/piston clearance.
Anybody know for sure if the 1.5/1.6 NA solid or hydraulic cams are any different than the turbo cams?
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Anybody know for sure if the 1.5/1.6 NA solid or hydraulic cams are any different than the turbo cams?
Quoting from the SAE white paper,
The intake valve has a maximum valve lift of 8 mm. Intake opening is at 5 degrees aTDC and intake closing at 14 degrees aBDC where both timings are rated at 1 mm of camlift. The maximum valve lift of the exhaust valve is 9mm, with opening and closing at 27 degrees bBDC and ~ degrees bTDC respectively. Intake valve clearance is 0.2 to 0.3 mm, and exhaust valve clearance is 0.4 to 0.5 mm. All these geometrical dimensions are identical with that of the 4-cylinder naturally aspirated Diesel engine.
(my emphasis added.)
The whole white paper is on Roger Brown's site at http://www.4crawler.com/Diesel/SAE/vwtdsae.shtml. If you are interested in these engines, it got lots of info.
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solid and hydrolic are different but same for na and turbo ( in europe!)
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I know that Piers at Piers Diesel Res. takes a stock camshaft and regrinds the camshaft for the cummins in the Dodge diesel trucks and the results is faster spool up, reduced egts, a little better mileage. They also offer new and billet camshafts. I would suspect that he could also do that to a vw camshaft. good luck JimK
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I know that Piers at Piers Diesel Res. takes a stock camshaft and regrinds the camshaft for the cummins in the Dodge diesel trucks and the results is faster spool up, reduced egts, a little better mileage. They also offer new and billet camshafts. I would suspect that he could also do that to a vw camshaft. good luck JimK
If I recall correctly, Piers take cams to Colt Cams (http://www.coltcams.com) for the regrind. That's where I got my VW TDI cam done and my TD cam might be sent there as well.
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How does it work?
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Most interesting info and a great discussion...thanks!
Mike, I missed your "naysayer" post on the other thread, but I don't understand why you think cams can't help the performance of a diesel, or is that not what you meant?
On the old forum there is a thread where a guy from the UK talks about fitting a solid lifter (83-84 JH?) GTI cam to his 1.6TD. He was so impressed with the increased performance that he had Piper Cams grind him a custom version that is even better. Looking at the table on the link I am guessing that there is little or no overlap with a solid GTI cam, but with its greater duration and (maybe) lift it can flow more air at higher RPMs. I can't access that forum from work, but will try to find it later if someone doesn't beat me to it. :mrgreen:
Sorry, I'm not believing it. I tried a J cam (solid lifter from a JH engine) in my diesel head once. Valves hit pistons when I turned the crank by hand. Unless this guy machined something for more clearance, there's no way he actually ran the engine with a 049J cam installed.
IIRC, The J cam (vw part number 049 109 101J) has about 7 degrees with both valves closed. The diesel cam has around 11 degees with both valves closed. The J cam has 0.369" of lift (both intake and exhaust), and the diesel has 0.315" of lift on the intake valves and 0.354" of lift on the exhaust valves. Intake valve clearance is the big limiting factor. On the diesel with the stock cam, the valves come within 0.2mm to 0.3mm (0.008"-0.012") of the piston.
You might be able to grind the diesel intake opening profile and exhaust closing profile onto the J cam and get something that works and delivers better performance than the stock diesel cam. You might also be able to cut some valve relief into the pistons for valve clearance, but again, you would have to be careful not to remove any moer than necessary for valve clearance, and that might lower compression more than you want (see chart above).
The J cam does have enough duration to run optimum volumetric efficiency somewhere around 4500-5000 RPM's. For duration, it's just about right for the diesel engines. The problem is valve to piston clearance with that cam installed.
Sorry I took so long to reply, but I've been on the road racing with Champcar's Totyota-Atlantics.
Rest assured that I don't 'believe' it either. I am passing along the info-lead as part of a conversation. As noted by QuickTD, Simon clearanced the pistons (and head) to make it work. FWIW, Simon is very credible in UK TD performance circles, so if something I wrote about him seems unlikely, the fault is probably mine... ;)
Edit: I was going to add that I have both "G" grind and a Callaway "C" turbo grind cams. Might be fun to play with those on a high revver!
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I know that Piers at Piers Diesel Res. takes a stock camshaft and regrinds the camshaft for the cummins in the Dodge diesel trucks and the results is faster spool up, reduced egts, a little better mileage. They also offer new and billet camshafts. I would suspect that he could also do that to a vw camshaft. good luck JimK
If I recall correctly, Piers take cams to Colt Cams (http://www.coltcams.com) for the regrind. That's where I got my VW TDI cam done and my TD cam might be sent there as well.
Small world, I had heard that also, Mark, Piers, Bob and the rest of the guys there are very smart guys, good luck JimK
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I didn't see any comment regarding the need for a vaccume pump on the diesel. I thought I'd add the reason has nothing to do with the cam. It's because gas cars have a throttle (butterfly valve) and the diesel has no flow restriction like that to make vaccume.
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Anybody know for sure if the 1.5/1.6 NA solid or hydraulic cams are any different than the turbo cams?
Quoting from the SAE white paper,
The intake valve has a maximum valve lift of 8 mm. Intake opening is at 5 degrees aTDC and intake closing at 14 degrees aBDC where both timings are rated at 1 mm of camlift. The maximum valve lift of the exhaust valve is 9mm, with opening and closing at 27 degrees bBDC and ~ degrees bTDC respectively. Intake valve clearance is 0.2 to 0.3 mm, and exhaust valve clearance is 0.4 to 0.5 mm. All these geometrical dimensions are identical with that of the 4-cylinder naturally aspirated Diesel engine.
(my emphasis added.)
The whole white paper is on Roger Brown's site at http://www.4crawler.com/Diesel/SAE/vwtdsae.shtml. If you are interested in these engines, it got lots of info.
remember that in the SAE paper they are still using mechanical lifters.
so, NA and TD are the same as long as they are mechanical.
I still haven't seen the 1.6 hydraulic cam's specs anywhere :(
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I've analysed cam timings of some OEM 8V gasser cams and have found them to be very close to what several aftermarket vendors have been offering as performance upgrade cams. I have also run engine simulations and found gains running these cams over the OE Diesel units (simulations were done with TDI as baseline, but it applies mostly the same for IDI).
While not plug-and-play, you could install cams with P/Ns 026 101 109A (from A2 GX/HT), 026 101 109G (from A2 RD/PF), 048 101 109D (from A3 ABA), 050 101 109A (all A4 2.0 8V). These are all hydraulic cams. You may need to increase the piston-valve clearance by machining the valve pockets a bit deeper. Best to try fitting the cam in the head, remove all the valves except for one cylinder, place Plastigages on the piston with the remaining valves underneath each valve, bolt everything back together, turn the engine by hand, check the Plastigages and deepen the pockets as necessary. You will likely also need to machine the lifter bosses because the lobes will hit them otherwise.
Edit: if nothing else, each of the abovementioned cams give a big bump in lift. The least of them gives 10mm lift (.393") up to 10.6mm (.417").
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Each of the above gasser cams closes the intake valves 16-18 degrees later than the AAZ cam. This will drop the dynamic compression ratio by about 1 full point compared to the AAZ cam. Cold start will likely suffer, but this can be dealt with pretty easily by tricking the glow plug to come on at a higher temperature threshold.
The ABA cam has close to the same overlap timings as the AAZ cam so there should not be any need for valve-piston clearancing (but may still need lifter boss clearancing).
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I was able to get a 048 101 109D and it doesn't seem to need any more clearance on my hydraulic head, wait, going to the shed to take pictures ;)
TDImeister: do you have the hydraulic 1.6 cam specs?
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hydraulic 048D cam on hydraulic 1.6TD head
exhaust:
(http://naotefiques.no.sapo.pt/DSC01815.JPG)
intake:
(http://naotefiques.no.sapo.pt/DSC01816.JPG)
stock 068L grind intake:
(http://naotefiques.no.sapo.pt/DSC01817.JPG)
PS: just realized that when talking about clearance in the lifter bosses everybody refers to the TDI heads, so I might get lucky on this one :D
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Keep us posted when you get the 048D cam installed and running!!! Is this going into a 1.6TD? A long runner intake manifold and some head work would complement the cam very nicely! Sorry, I don't have any 1.6(T)D hydraulic specs.
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I have a usable hydraulic 1.6 head for that build, planning a 1.9TD head with Renault prechambers, but that won't be in the near future.
the only thing that is keeping me from using that cam is the pulley, a hybrid adjustable on has to be built from the gasser and the diesel ones.
Its a shame we don't know the hyd 1.6 cam specs, I can measure it, but that isn't as precise as having VW telling what it is :( (or should be)
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Maybe I'm mistaken, but I thought the 1.6 would use a keyed sprocket like the gas engines instead of the tapered sprocket?
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nop, it has to be adjustable in order to index the cam properly.
IMHO, it does have the key slots, both the pulley and cam, but its not supposed to be used.
diesel in front, gasser at the back
(http://naotefiques.no.sapo.pt/DSC01743.JPG)
EDIT: one can almost take a glimpse at the key slot on the diesel cam
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I believe shortysclimbin is trying to get a gasser cam with its keyed nose adapted for a Diesel. tdi rs (Simon) did this when using an adapted gasser cam, and another member in tdiclub called mojogoes (Steve) bought this engine from Simon.
One can conceivably fabricate an adapter sleeve that's shrink-fitted over the keyed nose, and the male part tapered like the Diesel. Better yet, cut-off the tapered nose off a dead Diesel cam and bore/ream a hole with shrink-fit tolerances to go over the gas cam.
The only important thing is to align the cam Cylinder 1 TDC to crankshaft TDC. On the TDI, one uses a locking tool that basically makes the end-slot parallel to the valve cover sealing surface, i.e. parallel to the head deck surface. I think one way it could work is to cut opposing grooves that are aligned to cam cylinder 1 TDC in the nose shoulder (I imagine the key serves this purpose on the gas cams) and align the grooves to some reference surface like the valve cover.
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I took your picture and quickly drew up what I explained above if you're looking at the cam from the nose end. I think it's easier to understand in pictures than in words. Hope that helps.
(http://i193.photobucket.com/albums/z114/daveo643/Tech/cam_nose_alignment-1.png)
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I use a different method to align the cam on my other cars:
crank locked on TDC (the correct one, some makings are off)
cam roughly on TDC (both cyl1 lobes down)
rotate cam till a valve touches the piston, scribble mark, rotate to the other side, scribble. then find the middle of those two marks and assemble everything.
wouldn't work with the VW keyless system I know :(
just for reference: my franken renault 1.9D has two teeth of clearance each side
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I believe shortysclimbin is trying to get a gasser cam with its keyed nose adapted for a Diesel. tdi rs (Simon) did this when using an adapted gasser cam, and another member in tdiclub called mojogoes (Steve) bought this engine from Simon.
One can conceivably fabricate an adapter sleeve that's shrink-fitted over the keyed nose, and the male part tapered like the Diesel. Better yet, cut-off the tapered nose off a dead Diesel cam and bore/ream a hole with shrink-fit tolerances to go over the gas cam.
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Why not size it so it is heat shrunk on, then drill and pin. Pin/s can be push fit as held in by covering taper on sprocket...
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also good idea, but I'm going for the classic solution.
three part adjustable cam sprocket, inner part made from a gasser one, outer from a diesel one.
easy to adjust so timing can be spot on, and no worries of slipping
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I belive i am going to put a 2.0l cam in my 1.6. I am rebuilding a 1.9 head and installing rings in my engine so i belive i will do this then. It sounds like i should only have to mill the valve reliefs a little with the ABA cam. If the 1.9 head and loss of dynamic comp. from the cam is to much for winter use i'll put the 1.6 cam in it fot the winter.
Does anyone have the link to the write up about the TDI with the cam?
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No one has the link to the cam write up? I know i saw it once but can't find it now. I'm doing this next wknd and wanted to find some more info on it.
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does anyone know if they changed the gasser cam pulley over the years?
I have a MK1 gasser adjustable cam gear that I am going to modify to use the diesel outside, but I have a lead on a MK3 ABA camshaft, I was just wondering if there will be any issue putting the MK1 pulley on a MK3 cam.
thanks
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They are all the same. You can use it on the ABA cam.
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sweet, cause I already bought the cam, $50 shipped.
now we will have to see how well it fits, and how much piston machining it takes to work properly.