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222/228 at .050" duration, and he is not happy with the low RPM end of the main torque band, and his engine is supposeldy not lacking in compresion ratio
I honestly don’t get why he has no low end torque. I ran a .432” lift, 224 degree @ .050” cam in an 2.0 liter automatic Manta with a 3000 rpm converter. It was very well mannered and had plenty of low end grunt. 0-60 mph in 8.2 seconds, 0-100 mph in 22 seconds.

I’ve run cams in the mid-240 degree @ .050” range on 2.2’s and they had great power everywhere.

Something isn’t adding up.
 

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Opeler
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I honestly don’t get why he has no low end torque. I ran a .432” lift, 224 degree @ .050” cam in an 2.0 liter automatic Manta with a 3000 rpm converter. It was very well mannered and had plenty of low end grunt. 0-60 mph in 8.2 seconds, 0-100 mph in 22 seconds.

I’ve run cams in the mid-240 degree @ .050” range on 2.2’s and they had great power everywhere.

Something isn’t adding up.
Maybe it’s the dual 45s....? Not being dialed in totally?

My converter is 23-2500rpms.

Valve spring collapse isn’t helping I’m sure.
 

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My converter is 23-2500rpms.
Stock is 2200-2400 in a 1.9. With a bigger (torquier) engine, it will naturally increase....a stock converter would be this high or higher.
 

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Opeler
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Discussion Starter #44
A stock hydraulic 1.9 cam has less than 200 degrees duration @ .050”, and a stock solid lifter solid cam has less than 210 degrees @ .050” duration. The opening and closing ramps are VERY gradual on the stock cams.
Bob, so the chart posted shows the 1.9 cam (I'm told the 1.9 S/H is the US cam in the GTs) is a 308 duration. Is that for seat to seat? So the .050 spec is really below 200? That's s huge difference! For comparison the OR-99 lists a 300 duration seat to seat and a 252 duration at .05". Is that all due to the ramp design?
 

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Bob, so the chart posted shows the 1.9 cam (I'm told the 1.9 S/H is the US cam in the GTs) is a 308 duration. Is that for seat to seat? So the .050 spec is really below 200? That's s huge difference! For comparison the OR-99 lists a 300 duration seat to seat and a 252 duration at .05". Is that all due to the ramp design?
Ramp design, and rate of acceleration. Even the OR-99 is very old school, having been designed in the 1970’s. Modern cams have much, much faster opening rates.

The solid camshaft I’m putting in my rally engine is rated at 304 degrees advertised. It is rated at 266 degrees @ .050”. If you went by the advertised numbers, it’s ‘smaller’ than a stock cam by 4 degrees. But in truth it has 59 degrees more duration than a stock solid lifter cam @ .050”. The solid lifter cams measure out to 202 intake/207 exhaust duration @ .050”.
 

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Opel Rallier since 1977
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Everybody.....the stock cams in the Euro specs are seat to seat duration... that is not advertised duration. Bob, you advertised duration on your solid cam there is measured at .015" or .020" lobe lift. So the Seat to seat of that 304 advertised cam is much larger than that.

Everybody really, really, really needs to toss out the Euro specs of 300+ degress and STOP using those number for anything. They are meaningless for evaulation of the cam performance, DCR, etc.
 

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Opeler
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Discussion Starter #47
Everybody.....the stock cams in the Euro specs are seat to seat duration... that is not advertised duration. Bob, you advertised duration on your solid cam there is measured at .015" or .020" lobe lift. So the Seat to seat of that 304 advertised cam is much larger than that.

Everybody really, really, really needs to toss out the Euro specs of 300+ degress and STOP using those number for anything. They are meaningless for evaulation of the cam performance, DCR, etc.
Mark, then please post the correct specs for the stock opel cams because that chart is all that we have, at least that I can find.
 

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Opel Rallier since 1977
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Your wish is my command Mike LOL

here are some stock 1.9L Opel cam results. I have a head that I can put in a cam and directly measure the lobe lift. The numbers are reasonably accurate IMHO: I take data every 1 cam degree +/-0.1 degree, which is the same as every 2 +/-0.2 crankshaft degrees, and record lobe lift to .0001", within an reading window of .0002". Cam duration numbers are in crankshaft degrees, and that standard is used below.

This cam PN is 3 456 700, and is a hydraulic cam. It came out of the head of my '75 Opel which has a '74 casting date. It is the same PN of another cam that came out of an earlier '72 head. How this cam relates exactly to the 'stock' cam being sold today by OGTS is not known to me.

Exhaust:
Lobe lift: .244"
Seat to set duration: 304 degrees
Advertised duration at .006" lobe lift: 248 degrees
Duration at .050" lift: 200 degrees (Edited 40 minutes later to correct this)
Notes: The seat closing angle is +156 degrees after the exhaust lobe center, and the seat opening angle is -148 degrees before the exhasut lobe centerline. So the valve closing is a bit more gradual than the valve opening.

Intake:
Lobe lift: .244"
Seat to seat duration: 320 degrees
Advertised duration at .006" lobe lift: 260 degrees
Duration at .050" lift: 198 degrees

Here are the plotted lobe lift and lobe velocity on the opening side of the exhaust lobe. The degrees on the horizontal axis are relative to the lobe peak. Note: Figures below corrected to show crank degrees.

Stock 1.9L Opel Cam Exhaust Lift.png
Stock 1.9L Opel Cam Exhaust Lobe Velocity.png
 

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Opel Rallier since 1977
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I honestly don’t get why he has no low end torque. I ran a .432” lift, 224 degree @ .050” cam in an 2.0 liter automatic Manta with a 3000 rpm converter. It was very well mannered and had plenty of low end grunt. 0-60 mph in 8.2 seconds, 0-100 mph in 22 seconds.

I’ve run cams in the mid-240 degree @ .050” range on 2.2’s and they had great power everywhere.

Something isn’t adding up.
Eric does not have a stock torque converter. He has stated the stall speed as being in the 2000's range. If Bob's good experience with that [email protected] cam was with a 3000 RPM stall converter, then it seems that the mystery is answered or at least partially so.
  • Eric's cam is not reaching the lower end of the main torque band when the torque converter is locking up/reaching stall speed. So it is trying launch with the RPM's below the main torque band of the engine. That's just like releasing the clutch at too low RPM's on a manual trans... the engine bogs.
  • Eric reports that after the engine revs up some, THEN it takes off. That makes all the sense in the world; it is finally revving up to the RPM where it reaches the main torque band. This maoin torque band is when the exhaust scavenging is starting to work and volumetric efficiency jumps up to around 1.0.
  • So it is pretty simple to see IMHO: The cam is putting the main torque curve too high in RPM for his TC's stall speed. This is a pretty classic and well known problem; happens all the time when folks cam up an engine and don't change the TC stall speed to move up in RPM along wiht the main torque band.
  • He does seem to have decent static and dynamic CR with the 222/228 cam. That ought to make the drop of torque less severe when RPM's below the main torque band, but it is not what he likes. A lot of what constitutes 'good torque' or 'good power' is subjective preference when we are driving and feeling what the car/engine is doing. This often presents problems in online discussions of what is a good combination, or cam, or whatever. One person's 'good' is another person's 'meh'....
Now, having blathered all of the above, yes, there could be other issues piling on too...
 

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Opeler
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Discussion Starter #50
Mark, good info but I don't think that is the GT 19S cam. Mu understanding is that the 75 FI cams are the 19E cams? I understood from Gill that all US GT 1.9s came with the 1.9S cam.
 

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Opel Rallier since 1977
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I know what has been said about the 19E but that is not accurate info IMHO, at least for the US motors. Plus I looked at the cam PN's and it is the same cam PN as my early head cam from a 19S. So I'd say to not get hung up on what car year I got it from and all that jazz, but use the fact that the PN is the same as what is from an earlier head from another 19S.

And I just looked in the US parts catalog: It lists the same cam for all 4 bearing cams from 1971 thought 1975, for the Kadett, GT, Manta, and Ascona.

Now... if you really want me too, I can toss the other cam in the test jig and make some quick checks. But I am not sure why the same cam PN would be different....???

What else is driving you to think this is not correct info?
 

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Eric does not have a stock torque converter. He has stated the stall speed as being in the 2000's range. If Bob's good experience with that [email protected] cam was with a 3000 RPM stall converter, then it seems that the mystery is answered or at least partially so.
  • Eric's cam is not reaching the lower end of the main torque band when the torque converter is locking up/reaching stall speed. So it is trying launch with the RPM's below the main torque band of the engine. That's just like releasing the clutch at too low RPM's on a manual trans... the engine bogs.
  • Eric reports that after the engine revs up some, THEN it takes off. That makes all the sense in the world; it is finally revving up to the RPM where it reaches the main torque band. This maoin torque band is when the exhaust scavenging is starting to work and volumetric efficiency jumps up to around 1.0.
  • So it is pretty simple to see IMHO: The cam is putting the main torque curve too high in RPM for his TC's stall speed. This is a pretty classic and well known problem; happens all the time when folks cam up an engine and don't change the TC stall speed to move up in RPM along wiht the main torque band.
  • He does seem to have decent static and dynamic CR with the 222/228 cam. That ought to make the drop of torque less severe when RPM's below the main torque band, but it is not what he likes. A lot of what constitutes 'good torque' or 'good power' is subjective preference when we are driving and feeling what the car/engine is doing. This often presents problems in online discussions of what is a good combination, or cam, or whatever. One person's 'good' is another person's 'meh'....
Now, having blathered all of the above, yes, there could be other issues piling on too...
I understand his converter isn’t stock. But the numbers he’s giving are basically 100 rpms more than a stock converter. A stock 1.9 is in the 2200-2400 range. In a larger engine with more torque, it will be higher still without modification.

His engine should be making decent torque by 2000-2200. The specs aren’t that crazy.

My old 2.0 liter made its best power from 2500-6300 rpms. His cam is barely bigger, and his engine displacement is 10% higher, so I would expect the same or better low end characteristics.
 
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The US 19E cam is not the same as the Euro spec cam, the US cam is hydraulic while the Euro one is solid. The engines doesn't have much in common, except the block. I suspect that the US spec L-Jetronic is different too.
 

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The US 19E cam is not the same as the Euro spec cam, the US cam is hydraulic while the Euro one is solid. The engines doesn't have much in common, except the block. I suspect that the US spec L-Jetronic is different too.
Thanks for the info; that has been what I have come to suspect. The '75 block here may have the 19E stamped on it, but it has the same internal guts, like pistons and cam, as the earlier US engines. Emissions is one factor; the US was considerably further along the path of clamping down on emissions than Europe in the early and mid-70's, and I'd guess that drove a lot of the US engine parts.
 

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Mark, good info but I don't think that is the GT 19S cam. Mu understanding is that the 75 FI cams are the 19E cams? I understood from Gill that all US GT 1.9s came with the 1.9S cam.
Just a bit more info on what is going on with the specs:
  • OGTS appears to me to be publishing lift and duration numbers straight out of the old Isky catalogs for everything but the OGTS stock cam, and those numbers are for the old Isky solid grinds. The numbers may well be different for hydraulic grinds
  • Case in point, I have a hydrualic Torquer cam from OGTS that I got a few months back. The OGTS data says 256* (presumably that is advertised as it makes no sense for the .050" duration), but I measured it directly and at the standard .006" lift for advertised duration, it is 268 degrees, not 256. Now the good news is that the lift measurement came out in 100% agreement: they list .407" and I measured .4065".
  • It is known in some hot rod cirlces that Isky has changed their standards for duration measurements over the years. (That is not a bad thing, as they were a pioneer in the business, and the establishment of standards was up in the air for a while. I can recall when not everyone published .050" lift numbers.) So, that 256 duration mentioned above could be at .008" or .010" lifter lift. You always have to be a bit skeptical with Isky duration numbers on older cams, at least those that are not clearly listed as .050".
  • OGTS lists the lift on the 'stock' cam as '~390'. The tilde (~) means approximately in engineering work! So what is it really? IDK. More squishy numbers.....
So here we are: Old Isky numbers that mean what exactly? Euro duration numbers that you can't really use for anything. 'Squishy' data.... yep, no wonder it is confusing! We are at a bit of a disadvantage here in USA Opel-land..... I can promise you that this data is not nearly so squishy for the US V8-land cam specs.
 

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OGTS lists the lift on the 'stock' cam as '~390'. The tilde (~) means approximately in engineering work! So what is it really? IDK. More squishy numbers.....
FWIW, years ago I got my hands on a couple of NOS Opel solid lifter cams (1968-1970 US spec) and sent one to my old cam grinder. He ran it thru his Cam Doctor and it measured out at .385” lift.
 

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That's is good to know Bob. That might be a reason for the OGTS number. Now is it really that? IDK. I'd like to get my hands on one to see. It would be better to have that bit of extra lift than not.

But with the difference that you reported between the specs of the solid OR-4 cam, and what I recently measured on the OR-4H cam, we really need to see both flavors of each size (solid and hydraulic).

BTW, if anyone has a cam that they want measured, I'll open the door to discuss doing it; just send me a PM. It takes more care than anything and a few hours of time, and I've got the srpeadsheet set up to do the plots. It is something that interests me, as it is so vital to engine behavior.
 

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I understand his converter isn’t stock. But the numbers he’s giving are basically 100 rpms more than a stock converter. A stock 1.9 is in the 2200-2400 range. In a larger engine with more torque, it will be higher still without modification.

His engine should be making decent torque by 2000-2200. The specs aren’t that crazy.

My old 2.0 liter made its best power from 2500-6300 rpms. His cam is barely bigger, and his engine displacement is 10% higher, so I would expect the same or better low end characteristics.
I think that the question of what the user deems to be 'decent torque' is the crux of the matter. And the TC response depends on where the engine is on the torque curve when the TC starts to lock up; if the RPM's are down below lower end of the main torque band then the torque is lower, the TC stalls at a lower speed and it all feeds upon itself to make the bog more pronounced.

If I wanted the torque to be 'decent' at 2200-2300 RPM, then, based on past experience, I'd be looking at cams with a .050: duration of 210-212 and an LSA around 112. The rest of the cam specs would be built around that; then the static compresison ratio selected to work the DCR out right, and so on..
 

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My thoughts, are to run a .475” lift (or thereabouts) cam, with low to mid 240 degree @ .050” duration. 112 degree LSA. A 2.6 will eat that right up.
Do you know of any off-the-shelf cams similar to the above? If not, is there a custom grinder you prefer?

BTW: Right now I'm running an Enem P13 with LSA modified to 113, which has 11.2/0.44 lift; so a bit down from above.
 

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Opeler
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Discussion Starter #60
Wow, so much information. So after reading this about 4 times now here's a summary I think with the best points:

  • cam specs are all over the map and seems many spec them differently - very frustrating to say the least.
  • however seems that once you understand the above and that you must compare apples to apples and understand the lobe design then it makes better sense
  • 0.050" lift seems to be the more common American spec however the Opel cams don't list these numbers so good luck.
  • the older Opel cams and Isky cams such as the OR 66,77, 99 are old style lobes with very slow ramps, good for hydraulics but still old school
From RB:
  • The 2.4 heads love valve lift. In fact there is ZERO advantage to running the raised port heads (2.2/2.4) if you are running a low lift cam. A 1.9 head that is similarly prepped will outflow the 2.4 head at lower lifts. They only START to beat the 1.9 heads at around .425-.450 lift.
  • Also, for a bigger displacement street engine (2.4 - 2.6L), 112 degree lobe separation angle works well. The bigger guys like the wider numbers. As an added benefit the idle is smoother and the power band is broader.
  • Recommended numbers are about a .475” lift (or thereabouts) cam, with low to mid 240 degree @ .050” duration. 112 degree LSA.
So, as mentioned before the GM77 cam lists as 0.465" lift and 0.05" duration of 238 with 109 degree LSA. Previously Bob you recommended having this cam ground at the 112 degree separation. So that leaves me with a few questions:
1. Are the lobe designs (ramps) of a more modern style and suitable for hydraulic lifters?
2. Is this something that Isky can do there in California?
3. Finally what valve sizes would you recommend?
4. What valve springs are recommended?

Caveats, 2.6L bottom end, no real head work other than maybe some unshrouding around the valves to take advantage of the 97 mm bore.
 
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