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The cam, at this point, is more aggressive than I would like. If you are looking for a smooth running street machine I would go for a torquer. You will still have plenty of zip with less noise.
Honestly that cam isn’t that big, not for a 2.2. If you had individual runners (twin DCOE) or ITB’s it will be mellow. A large plenum will always exacerbate the cam overlap.

I’ve run a similar cam in a 2.2 with twin 45 DCOE’s and it was downright mellow. Smooth idle at 900 rpms.

Duane Foley’s Manta runs a 2.5 with 257 degree @ .050”, .504” valve lift and it is equally tame due to the individual runners.
 
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Good write up Gold... many thanks. If you run across any info on the durations at low valve openings, I'd love to see it. Whose cam lobe profiles are those?
Cam Techniques, but you would have to visit heaven to get one.
 

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Opeler
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Discussion Starter #23
I'll admit I know very little about cams but if one was to take the stock specs of the 2.4 cam, what readily available cam would one of you engine experts recommend for a daily driver sport car? How about one of the OGTS cams? Three options available but two are shown as racing only, not street.

1. New higher-performance "Combination" camshaft, featuring .430" lift and 268 duration specifications. Improves your street performance. Specify solid or hydraulic grind. Contact Opel GT Source for additional details.

mike
 

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I'll admit I know very little about cams but if one was to take the stock specs of the 2.4 cam, what readily available cam would one of you engine experts recommend for a daily driver sport car? How about one of the OGTS cams? Three options available but two are shown as racing only, not street.

1. New higher-performance "Combination" camshaft, featuring .430" lift and 268 duration specifications. Improves your street performance. Specify solid or hydraulic grind. Contact Opel GT Source for additional details.

mike
That's a fairly popular cam. I run it in my 2L but it's fare from anything overly radical.... I'd figure you'd want something a bit more aggressive for such a large engine as yours....
 

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Opeler
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Discussion Starter #25
Copy Vincent. Are the other cams from OGTS (listed as racing) that would be more applicable or suitable for this build?
 

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I'd actually tend towards some version of that Combination Cam. The duration is very similar to that used in a lot of 5L V8's for a good, middle ground of performance. You will have basically 1/2 of a 5L V8.

What I would want is something a bit quicker in the ramps with a bit more lift than the traditional Isky Opel grinds. Isky has a master list of lobe profiles, and I would look to that. http://www.iskycams.com/userfiles/files/ISKY-Master Lobe List.pdf

Look at page one for the hydrualic grinds. Skip the RV and lift rule cams, and go to the 3rd group. Something like the H569 or H438 look good to me; decent lift, quick but not tooooo quick so as to be so hard on the springs and valvetrain, and not too large as to drop your low RPM torque. I'd prefer it on a 110 LSA for street use (and fuel mileage) but that is subject to comment and debate; a 108 might be better for that lower rod/stroke ratio. How the exhaust ought to be set in comparison to the intake on that head, IDK.

You can look up solids in the same street range, in the top section of page 4, but I don't see anything better there with a quick glance.

BTW, Mike, what is the expected static CR of your new engine?
 

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A couple of things to consider.

First of all, 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 street engine anyway, I’ve seen very good results on the 2.4/2.5 engines with 112 degree lobe separation angle. Stock Opel is 110 degrees. I run tighter LSA for 1.9 and 2.0 engines. But the bigger guys like the wider numbers. As an added benefit the idle is smoother and the power band is broader.

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.
 

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Opeler
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Discussion Starter #29 (Edited)
How radical cams can the Holley Sniper cope with ?
I have no idea. The interface menu allows you to choose stock, mild, or racing cam in the setup but I have no idea what that would really equate to on an Opel engine. I'm probably the first person to attempt the Sniper on the Opel engine to this level.

Also the static compression looks to be no lower than 9.6 and that assumes a little extra dishing of the piston tops.

Bob, sounds intriguing on that cam spec! Is there a stock cam that meets those specs?
 

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Opeler
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Discussion Starter #30
A couple of things to consider.

First of all, 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 street engine anyway, I’ve seen very good results on the 2.4/2.5 engines with 112 degree lobe separation angle. Stock Opel is 110 degrees. I run tighter LSA for 1.9 and 2.0 engines. But the bigger guys like the wider numbers. As an added benefit the idle is smoother and the power band is broader.

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.
Bob, thanks and good information! So those specs seem similar to the GM77 cam with valve lift of 0.465 and duration of 238 @ 0.05 although the lobe separation on that cam is only 109 degrees. That cam shows a duration of 276 which I assume is the fully seated spec. Plugging those numbers into the Pat Kelly DCR calculator gives a opening and closing angles of 26 and 70 degrees for the cycles and the DCR comes out to 7.44 for my 2.6L combo build. Question: For a cam that is timed at 0 does the lobe separation and intake lobe centerline equal each other?
 

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Question: For a cam that is timed at 0 does the lobe separation and intake lobe centerline equal each other?
Yes, a 109 degree lobe separation angle installed straight up has a 109 degree intake centerline.

Why not have the cam ground with 112 degree lobe separation? If you are ordering it new anyway...
 

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Can we back up and answer one very important question? What are the main uses and goals for this car/engine? Please express it in terms of in what activities the car is to be driven, the transmission type, the rear gearing, the importance of fuel economy, how much you want or expect to rev things (and the degree of desired of hooliganism on the street LOL), and so forth.

BTW, that 276 duration is not the fully seat-to-seat spec but the 'effectively seated' spec. In US hydraulic cams, that would usually be measured at .005" or .006" lift of the lifter and is called advertised duration.
 

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Opeler
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Discussion Starter #33
So the main use/desire is a daily driver that is reliable but obviously as much power as reasonable given the bottom end design. Not looking for a race engine so therefore not looking for a high rev or high speed engine. To recap 97 mm pistons, 88 mm stroke, and 136 mm rods. I understand this combination favors a low rpm torque motor versus the high revving engine so that's perfect. The short block is done and went together perfect according to the machine shop I talked to today. They need .010" undersized main bearings which I ordered from Gil today. Tranny is the Getrag 5-speed. Chatting with Gil today he recommended keeping the stock valves and springs and using the 1.9 cam versus the 2.4 cam. Rationale is that since the goal is not a high revving race engine, the need for bigger valves and cam would not be realized. Makes sense to me and I should still hit 6000 rpm just fine. So does anyone have all the specs on the 1.9 cam (19S cam)? All I can see from the cams cams cams thread is 308 duration and 110 lobe centers. I assume that duration is the seat to seat number?
 

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Opeler
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So the main use/desire is a daily driver that is reliable but obviously as much power as reasonable given the bottom end design. Not looking for a race engine so therefore not looking for a high rev or high speed engine. To recap 97 mm pistons, 88 mm stroke, and 136 mm rods. I understand this combination favors a low rpm torque motor versus the high revving engine so that's perfect. The short block is done and went together perfect according to the machine shop I talked to today. They need .010" undersized main bearings which I ordered from Gil today. Tranny is the Getrag 5-speed. Chatting with Gil today he recommended keeping the stock valves and springs and using the 1.9 cam versus the 2.4 cam. Rationale is that since the goal is not a high revving race engine, the need for bigger valves and cam would not be realized. Makes sense to me and I should still hit 6000 rpm just fine. So does anyone have all the specs on the 1.9 cam (19S cam)? All I can see from the cams cams cams thread is 308 duration and 110 lobe centers. I assume that duration is the seat to seat number?
I’m in a very similar boat. I have a 2.2 and he’s recommending going with a 1.9 cam in my motor as well. I want low end torque and the power I should have from my 2.2 bored 0.030 over. My current car has too high of a powerband for my habits. I’ve asked about the torquer cam but I’ve been told twice, 4 years apart (when I built it) that it wasn’t a good choice due to my automatic. I have read the Cams Cams Cams thread a few times and I am still trying to understand how my old stock 2.2 cam compares to the 1.9 cam. The only thing that I think specs it out is this attachment:

427658


Eric
 

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Makes sense to me and I should still hit 6000 rpm just fine. So does anyone have all the specs on the 1.9 cam (19S cam)? All I can see from the cams cams cams thread is 308 duration and 110 lobe centers. I assume that duration is the seat to seat number?
Worthy noting that the bigger the engine, the lower the rpms for peak power and torque for a given camshaft. A stock 2.4 makes peak power at 4800 rpms. It is all done by 5200. Any higher is abuse, wear, and noise. The power falls off fast.
With a 2,6 liter engine, the peak power will occur even lower. You actually need a really nasty cam (relative to a 1.9) just to make ANY power at 6000 rpms. For example, it takes about 250 degrees @ .050” duration to make peak power at 6300-6400 in a 2.5 liter CIH. And that’s with big valves and serious porting. With stock ports and valves it’s all done by 6000 rpms, even with that cam.

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.
 
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Thanks. The use and goals (application) is the most important thing to get established!

Yes, and number around 300-ish is a seat-to-seat duration and is not what you put in for a DCR computation.
 

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Opeler
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Worthy noting that the bigger the engine, the lower the rpms for peak power and torque for a given camshaft. A stock 2.4 makes peak power at 4800 rpms. It is all done by 5200. Any higher is abuse, wear, and noise. The power falls off fast.
With a 2,6 liter engine, the peak power will occur even lower. You actually need a really nasty cam (relative to a 1.9) just to make ANY power at 6000 rpms. For example, it takes about 250 degrees @ .050” duration to make peak power at 6300-6400 in a 2.5 liter CIH. And that’s with big valves and serious porting. With stock ports and valves it’s all done by 6000 rpms, even with that cam.

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.
So why are two people with larger displacement engines being guided towards the 1.9 cam? I believe that both of us want low end torque and spend most of our time in that lower band. 6000 rpm is just when it you are flooring it before shifting
 

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And to add to Bob's post...
  • I do not expect a 1.9L cam to work anywhere near 6000 RPM in the longer stroke and bigger displacement.
  • The idea of stock sized valves... maybe for the 2.4 sized valves. But flow at lower lift can be helped with a proper valve setup. I don't quite see the rationale.....
  • I am very concerned over the dynamic compression ratio with a small 1.9L cam in either the 2.6L or Eric's 2.2L. I don't want to see DCR go above 8:1 for a daily driver. Detonation can be the result. But we need to know the 'advertised' duration for the stock 1.9L cam. I guess I will be doing a 1.9L hydraulic cam profile tomorrow! The system is set up right now.
  • To Bob's point on the .050" durations, I just profiled an old Norris cam and I think it is a stock solid cam as the .050" duration ended up being only 206 degrees on the exhaust side. (Now, the advertised duratoin and the lack of lash ramps on this cam are not making sense for a solid cam.. but that is another topic.)
  • I depart from Bob in the area of cam size for a daily driver. And Eric's cam is supposedly 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
 

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Opeler
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Discussion Starter #39
Oh man I'm so confused now! LOL Willing to do what ever is right, as long I only do it right this time. Don't want to redo another engine at least for a while.
 

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Opeler
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Oh man I'm so confused now! LOL Willing to do what ever is right, as long I only do it right this time. Don't want to redo another engine at least for a while.
I feel the exact same way and I’m redoing part of mine with less than 100 miles on it after being rebuilt 4 years ago. Part of me thinks my cam would be fine and I should try to conquer the beast, but another part says to just make it simple and get it on the road and have fun with it. I just need to be 100% sure that whatever cam I choose right now gives me the results I’m looking for, which is low end performance and streetable for around town, while cruising well on the highway. I’m not a racer and never will be, just need it to get up & go when I push that little pedal on the right!
 
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