Opel GT Forum banner

1 - 20 of 105 Posts
G

·
Guest
Joined
·
0 Posts
Discussion Starter #1
I have been conversing with numerous parties in Europe about the development of an improved Opel CIH valvetrain. This is not for the faint of heart (or wallet), but is for serious high performance use or racing. Essentially, about six of us are working on a project to allow the use of roller rocker arms, roller lifters, and a billet roller camshaft in a CIH Opel engine. We are interested in the benefits of a nearly bulletproof valvetrain, with greater rpm potential, greater torque and power, and less component wear. If anyone is interested in this, please contact me, I am trying to establish a quantity of potential buyers to help baseline a buy-in for the custom-made components. A rough guesstimate on the pricing is $1400-1800 for a cam/lifters/rocker arms/stud girdle. Thanks.

Bob Legere
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #2
you know me Bob i am interested


David Ligon
Davegt27
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #3
The owner of the company interested in making the roller lifters called me today (yes I said interested....he contacted some Opel guys in Europe and offered to make the roller lifters, not the other way around!). I sent him a cutaway of an Opel head, a stock cam, etc. He says that it will be very easy for him to create a roller lifter for the Opel based on other designs he already has. He just needs to know how many he can sell, and he will quote it and start production right away. I know of numerous people in Europe awaiting this performance upgrade. But so far only one reply in the US (thanks Dave!). Any more interest in this? WE are looking at probably an entire package. Rocker arms, lifters, billet steel roller cam, valve springs. Valves could be supplied as well, or not. We´re talking super lightweight stuff here too. Roller lifter weight would be 62 grams!

Bob
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #4
Bob,

I would be interested in a set up for my money pit, I mean Manta.

Duane
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #5
I´d probably be interested in a year or so when I build a race only engine. It sounds like they may be price prohihative for street use.

James
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #6
I would be ready for it in six to eight months. Would this be offered as both partial and complete kits? If partial I could probably support the project sooner.

Phil
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #7
I may be interested depending on cam profiles. I want one very agressive, something that will pretty much get me to the track or show and back, but no other street driving besides that. $1500 would probably be my top end for cam, lifters, rockers, girldle and hopefully springs/retainers/locks. Valves would be ok as an extra
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #8
Well, if this had been happening this time LAST year, I´d have been all over it, Bob. But who knew . . . I bought a new Isky flat-tappet cam, lifters, rocker arms & bearings, the whole nine yards. Sort of shot my financial wad on the old valvetrain technology, you might say. If I had it to do over again, I´d take that money, add tax return & Super Bowl winnings, and REALLY have a badassed street motor . . . just HAD to build that 2.0 last year . . . :(
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #10
Gary, I think the lady Huskies would disagree with you!
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #11
More good news. Besides the fact that the roller cam and lifters are very feasible to manufacture, the pricing structure is better than originally anticipated. The owner of the company has quoted $650 for cam and lifters. There will also be the need to modify existing (Chevy) roller rockers, and add custom pushrods, but since these are off-the-shelf items than are merely modified, I believe the overall cost will be closer to $1000 for the complete setup, which is far less than my original estimate of $1500 or so. This does not include valves, but springs should be part of the deal, as they need to be more substantial to handle a roller cam´s more aggressive profile. This is sounding like it will be VERY promising. The owner also said he can supply the lifters and just the camshaft billet, for those who want to have their own profile custom ground.

Bob
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #12
I´m def in for that deal. Can it be done by say July? Any idea what the cam profiles will be as well?
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #13
The owner would love to put these into production ASAP, so we´re talking weeks or a month away. Cam choices will be limited to typical roller profiles, which is to say substantially more aggressive that typical street profiles. But should the need arise to produce a cam profile that he doesn´t offer, they can be ground by any manufacturer (Crane, Crower, Isky, Comp Cams, etc.) This was the reasoning behind the raw unmachined cores being available if you didn´t like his available profiles.

From my own experience, most roller cams *start* at around .450 - .475 lift and around 245 duration @ .050, and they grow from there. I will be speccing a cam with about .480 - .500 lift and around 255 duration @ .050 for my friend´s 2.5 Opel. It will remain a street-driven vehicle. My hillclimb engine will get around .580-.600 lift and around 275 duration @ .050. Radical, yes, but still tractable with a larger Opel engine (2.2 bored to 2.3 in this case). I suggest that the cam is kept under 250 duration for a 1.9/2.0 litre engine.

Lest this scare you into thinking a roller cam is TOO aggressive for the street, remember I´ve run similar flat tappet profiles in daily driver Opels for years with excellent driveability (carburetion and ignition tuning are more critical for driveability issues). One of my favorite *hot street* Opel flat-tappet cams has .460 lift and 246 duration, and it idles at 1200 and pulls from 2500-7000 nicely. A similar roller profile would idle smoother and make more power everywhere in the powerband.

With a roller camshaft, you can generally run a cam with about 10-15 degrees MORE duration than an otherwise comparable flat-tappet cam, and it will have nearly identical idle quality as the smaller flat-tappet cam, with better torque and better top end power. These are many of the reasons for going to a roller cam to begin with. And with roller rockers and a stud girdle, real-world Opel engines revving to 9000 and 10,000 rpms are possible if the shortblock is up to it!

Bob
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #14
The owner of the company making the roller lifters/cams for Opels is interested in taking orders now. I´m stepping out as the middle man. I merely was letting the public know they were being made available. So for those who´ve expressed interest in these items, please contact the company making them directly. Not doing so will reduce the quantity of the order and keep the price higher. The more that order, the more money to be saved!

Anyway, the company name is Cam Effects. The contact person is Chris Johnson, the company is in West Hills, CA. They can be contacted at (818) 883-1042, or by e-mailing at [email protected] . I am trying to get a list of camshaft profiles from which to choose from, and will be placing my own order as soon as I have selected my cams. For those looking to save a few bucks, or have not decided on a profile, he will sell the camshaft as a semi-finished blank that can be ground to spec at a later date. Roller rocker arms, stud girdles, and valve springs will also be available. You can order these items at a later date as well, the critical items to be ´mass produced´ are the lifters and camshafts.

For those who don´t think this is a major breakthrough, it most definitely IS! We need to support companies like this who are willing to produce exotic parts for our cars, they are not as common as Chevys! I will be ordering 4 cams and lifter sets initially, the prospect of smooth running roller lifters, higher rpms, far greater torque, and more power is very enthralling to me. Can you imagine a 2.7 litre turbo Opel CIH engine with roller rockers and lifters? Yoww!

Bob
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #15
Oops. Don´t know where the smiley came from in the phone number. It´s (818) 883-1042. Oh, and his website is up too, it´s www.cameffects.com so you can see a photo of the roller lifter design. Very nice design, very lightweight. Basically a lifter within a lifter, no guide bars to get in the way.

Bob
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #16
I´ll have my dad run my engine through his computer to figure out the cam profile that will best suit it.
Bob, can you provide an estimate of the flow numbers for a ported and polished 1.9 head with 1.72/1.50 valves so he can plug them in? I think the program wants samples at like .1 to .6 or so in .1" incriments. I´d rather use some general figures than wait until my porting is done to know what cam profile to order.

Thanks
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #18
Not knowing the person doing the porting of the head, it´s difficult to accurately estimate the airflow. As it turns out, I also cannot find my file with my old flow charts. I haven´t used the 1.72 valves for about 8 years now. But based on memory, I can give a little insight perhaps.

intake flow:
.100 - 34 cfm
.150 - 45
.200 - 57
.250 - 73
.300 - 86
.350 - 99
.400 - 103
.425 - 108
.450 - 110
.475 - 112 After this lift, massive turbulence sets in
.500 - 109
.525 - 108
.550 - 106

exhaust flow:
.100 - 28
.150 - 36
.200 - 50
.250 - 64
.300 - 76
.350 - 85
.400 - 88
.425 - 90
.450 - 92
.475 - 93
.500 - 95
.525 - 94
.550 - 95

Airflow numbers above were listed @ 10 inches of water. To convert to 25", multiply by 1.54, to convert to 28", multiply by 1.67.

Note especially the high proportion of exhaust flow at lower valve lifts. Also remember that the intake manifold will reduce intake airflow (a stock intake will choke intake airflow from 112 cfm to 88 cfm), while the exhaust manifold will increase exhaust flow by about 5 to 6 cfm. Now you can see the importance of improving the intake flow to maintain the balance. With a single downdraft intake (ported), and 38 DDGAS Weber, I still will make the intake cam profile about 6 to 10 degrees MORE duration than the exhaust profile. This has usually netted me about 8- 15 hp more than a single profile camshaft.

BTW, street Opels that are under 2.2 litres make the best streetable power with 108 degree lobe separation angle. If you want more mid-range torque, and don´t mind a rougher idle and giving up a little top-end power , then 106 degree works well. Great for short-track stock cars, hillclimb cars, and autocross cars.

Bob
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #19
I thought increasing lobe seperation would help mid range torque and reduce top end, not a decrease from 108 to 106?

Alan
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #20
Narrow lobe separation angles (102, 104, etc) will have a rougher, choppier idle, more overlap, and will have better mid range torque and power. It will have a narrower powerband, and at some point, when the power falls off, it falls off FAST.

A wider lobe separation angle will have a much smoother idle, less overlap, reduced emissions, and will have a wider powerband with a less distinct power peak. Power will not fall off as quickly on the top end. Most stock engines use a wide lobe separation angle, Opel uses 110.5 degrees. I´ve seen the best results with 108 degrees with most cams for street use and road racing, but I´ve had good results with 106 for short-track racing....the torque off the turns was better. Wheelspin off the turns at 55 mph with a welded (spool) rear axle!

Bigger Opel engines, especially fuel injected ones, need a wider lobe separation angle. The injection system can´t tolerate a lot of overlap, so you can add some duration to the cam but widen the lobe separation and still have the injection operate correctly. I´ve had good results with 112 to 114 degrees. The 2.4, for example, already has good torque, so it doesn´t need help here. However, the 2.4 power falls off rapidly by 5000 rpms, so the wide lobe separation helps extend the top end but does not adversely affect the bottom end.

I´ve made mention of this before, but my friend´s 2.5 litre I built has a severely ported head, and a mild hydraulic cam with .465" / .445" lift, and 222 / 218 duration @ .050". It has 112 lobe separation. It idles at 900 rpms smoothly, and pulls hard from off-idle. It continues to pull hard to 7000. It is unlike any stock 2.4 I´ve ever driven, yet is arguably just as driveable as stock. It has lost its *truck engine* feeling.

Bob
 
1 - 20 of 105 Posts
Top