Selecting The Best Camshaft

[Stev0]

I currently have a 1.9 CIH in my manta A, which will be getting a fully balanced bottom end, lightened flywheel, lightly ported cylinder head, twin 40's and a few other tricks.. Once i'm done playing with it, i'll move over to the bigger 2.2 CIH engine, same basic story with 45 or 48's, so I need to select a cam which i will use in the 1.9 for now, and in the 2.2 for later..

i've been pulling my hair out regarding this decision, as you have to decide on a camshaft based on your own drivestyle and where in the rev range you want the power to be.. I personally hate revving an engine past 6000rpm, as the odds of something going wrong start exponentially increasing from there (bad experiences).. as this is an oldschool RWD vehicle, i'd like to have excellent low-down torque, the engine must grunt, not scream... but that said, too much low down torque and a 950kg RWD vehicle becomes undrivable, especially if you get a bit of rain on your drive back from the breakfast run.. I also don't want to go through all the trouble of importing something that won't make a significant difference, as it's an expensive exercise.. Running twin sidedrafts eliminate the hassles of bad idling on a high duration cam as every cylinder gets it's own independant fuelling and air, so no limitations there..

it would seem that i'm torn between the Y12 (288deg, 2500 - 6500rpm) and the Y12/P13 (276deg, 2000-6000rpm) ENEM camshafts, BUT not limited to them as solid lifter are also easily acquired from the 1.6 head i have lying at home.. (also need to know if they are straight fit or not??)

Please advise..

Edited January 18, 2013 by Stev0

[lamchop77]

Stevo

My personal opinion is that you cant do what you want to. Any fast road style cam in a 1.9 will be basically like a std road cam in a 2.2. Bigger capacity CIH motors soak up duration like nobodys business. I ran a 244 kent in my 2.2 and it was a proper torquey motor putting out about 175-180 bhp, the idle was bit lumpy but nothing too bad. If that cam was in a 1.9 it would probably be equivalent to a race/rally cam.

My advice would be to forget about a single cam for both, look for a used 214 or a 234 kent cam for the 1.9. I had a 234 in a 2.0 and that was pretty pokey, 160 bhp approx and pulled well with 40's even tho they were right on the limit for size. Save your money and then get a fresh cam for the 2.2. The 2.2 will need 45's minimum I would look at Catcams as they have a few specs of cam for the CIH, think it was one of the owners of the company (something like that anyway) used to rally mantas so had a great deal of knowledge on tuning them.

Oh and do NOT use the 1.6 lifters if they have been used. They will knacker a new/used cam in no time. Kent do a set for about 80 quid, just get them, or just a std set from a motor factors. Yellowstorm racing do a set of aluminium lifters that can cut down on the valve train weight which helps to stop things going boom, but i'm not sure on the price.

HTH

Chris

[Retro Power]

I'd pretty much echo the above

Certainly a cam that is lively in a 2.2 is going to be rough low down in a 1.9

Re. the used followers, at £80 I'd get new ones, BUT you can re-use old followers if you linish the tops to get them dead flat and mark free. I use 800 grit wet and dry paper, stuck to a sheet of flat glass with lots of wd40.

At £80 though, new ones would be the best bet as cams are not cheap!

[Stev0]

i hear you... okay scrap the one cam for both motors idea, but i really can't afford to import 2 camshafts.. you reckon a 288deg cam will be too rough for a 1.9?

maybe then to save costs i could go the reprofiling route on the 1.9, just shim up the lifters etc.. how would a stock 2.2 cam perform on a 1.9 setup?

[monzta]

Enem Y12 P13 may suit you the best regarding your rev wishes.

They are direct fitment parts.

[Jason b]

This has started me looking a cam profiles for the 6cyl CIH. I never realised how ludicrous the duration was for a factory cam. Was this due to fears regarding valve gear wear? - I think a lot of companies were concerned about wear in the event of poor oil delivery around the time the CIH was designed. I wondered if this was opel being over-cautious in this regard?

(Feel free to school me on this as I know very little about cam profile design)

Jason

Edited January 19, 2013 by Jason b

[Stev0]

yeah the 2.2 was 285deg stock!!! that's insane!!

monzta will the Y12P13 cam still give me good gains?

[lamchop77]

Stevo

You need to check the timings against each other, and also check the valve lift. 2.2 cam hasn't got as much lift as a 214 kent, the 234 is meant for 2.0 motors. It has the same lift but full lift is at 103 degs rather that 107 so the cam timing is different. The y12 enem cam has 11.1mm of lift on a STD head, if any machining is done the valves will be closer to the piston. It was known that 214/234 cams can be fitted without problems with valve to piston contact and they are 10.89mm, the enem Y12 is appox 0.3mm more but that will prob mean that you need to pocket the pistons. The 244 is 11.34mm and that definately touched on a 2.2 engine and they have deeper piston pockets. It depends on where the lift starts and stops. The only way to find out is to do a loose build with plasticine on the piston top and see if they contact.

The duration covers both inlet and exhaust cycles so if a narrower LSA (lobe separation angle) is used the duration can come down but this makes a big difference to where the power is delivered in the rev range. Some of the bigger capacity CIH motor can benefit from have a split duration cam allegedly, one for the inlets and one for the exhaust!!

I would use the 214 its meant for the smaller capacity CIH, then i would get the build spec of your 2.2 and ring the cam men up and ask their advice. Kent will prob recommend a 244. Rallybob on opelgt forums is well clued up on this, see what he has recommended to guys on that forum, if you can't find anything pm him and he will more than likely give you a couple of options.

HTH

Chris

Edited January 21, 2013 by lamchop77

[Stev0]

i'm with you, i think..

just to confirm i understand you correctly, with the kent 244 in a std 2.2 head, the valves will definitely touch the pistons at 11.34mm lift?? but the 244 reaches max lift at 103deg, which is damn early anyway!!

sooo.. the higher the angle at which full lift is reached, the less likely the valve and the piston will meet, but at a sacrifice of power delivery?

if i understand the specifications correctly, then the Y12 camshaft reaches full lift at 109deg, later than both kent's you've mentioned, but since the lift is more, it might be at around the same clearance at 103deg as the "fully deployed" Kent 234? (one wouldn't know for sure unless an accurate profile graph was available...)

So what would you recommend is the deciding factor in choosing a camshaft, more total lift at a sacrifice of duration or more table-top duration at a sacrifice of total lift?

bigger intake area around valve head sacrificing time it stays fully open or longer time at fully open at the expense of itake area around valve head??

[lamchop77]

You need to look at the spec of your engine. Take lift for example if you have a valve size of 40mm you really dont need to lift beyond 10mm as the gain above that is usually non existant or slight, so using a cam that lifts to 12mm is pointless. But this isnt always the case as the head could be ported in a way to make it more efficient so that it does perform.

We know all that we are doing is getting as much air/fuel into the bore, but you also need time to compress the mixture and push the waste out. Its all a balancing act. Things are moving so fast at 5000-6000rpm you get very little time to do all that!!! Having a cam with a wide LSA will give you more torque, narrow it you get more top end power but if a street cam has an LSA of 107 deg and a race cam has the same they will not perform the same, as the lobe may have greater duration, therefore it will have greater overlap. Having that will give you the rough idle etc but will give you better power futher up the range.

With the CIH the bigger the capacity the greater the torque, the increase from a 2.0 to a 2.2 is BIG. Way more bottom end grunt, this means you can rely on the torquey nature of the 2.2 to pull from low down and then get the cam to come in further up the rev range. This is why you can go wilder on the cams than what you think, BUT all this links back to the comp ratio, conrod length, rod ratio's, airflow into the bore through the head and inlet tract, valve sizes, exhaust, etc

I talked to Dave Newman about a cam for my 2.3 long stroke motor telling him all the details of the engine and what i wanted from it. He came back with some figures of 304 duration with a 11.9mm valve lift.

Don't second guess ask the cam guys, they have the flow benches to test the cams they have designed and will have put hours into the design of them. I always do, i wish i knew more about it so i could say do this, do that but i dont have the money/time to put into it.

Chris

Edited January 22, 2013 by lamchop77

[611]

I have the Enem Y12 cam ( not fitted yet as will be getting the engine running with the old cam first ) and when i spoke to Jan at Enem he said on a standard head that had not been skimmed there would be no problem with clearance if the timing is setup properly. He also suggested as Chris did, that it was worth a test build to make sure everything was ok with the timing and clearance. He also said that full lift would be a bit later so when the piston is at TDC the cam will not be at full lift at this point but a little later.

Im no expert, so im going on his recommendations, so i hope he is right :-)

I have also been told that with a new cam you should run it in on first use, 2'000 rpm for 15 - 20 mins.

Andy

[lamchop77]

Yep thats right, and also make sure the engine starts quickly don't keep cranking if it wont start. It puts too much load onto the cam lobes. Also its a must as i am concerned to use engine assembly lube on the cam, i use the red Torco stuff from demon tweeks. There doesn't seem to be enough with the kits that you get, i literally coat the lobes and all the valve train contact points.

As 611 said the cams are designed around heads that haven't been skimmed. Do you know if yours has been? If not a trial build is a must.

Chris

[611]

Hey Chris

It your doing a test fit would you be able to re-use the head gasket or would you buy a spare to use as the test one? I will be fitting my head with the old cam to get all things working and then when all ok will do a quick test fit with the new cam, lifters, rockers etc.. before bolting it all back together properly for the bedding in of the new cam.

Andy

[lamchop77]

Andy you need a used gasket, defo can't reuse one. If i remember the crushed thickness is 51 thou, which by chance is the same thickness as thin zinc plated M10 washers. I drilled a set out to 12mm and used those in place of the gasket. Mind you mine is a Cometic MLS which is 120 quid not an 8 quid std one!!

I think you would probably be best just building it up with the proper cam in.

Chris

[611]

Hi Chris

Thanks for the info. Think i will get a cheap one and put it on and then use if for the test and then the one i have now can go on when the new cam goes in.

The reason for not building straight up with the new cam is the injection is just setup for a standard 2.0l engine so im not sure how it will run, or if it will run :-)

and don't want to put any wear or stress on the new cam while i get it going. Once i know it runs i will do the swap and then it will be off to get the injection all mapped up properly.

Its a Webcan system that im using on it.

Andy

[lamchop77]

Whatever way you do it the fueling wont be right at first anyway,so why do the same job twice. I assume the webcon system has a basic map with it, which should be fine for a 20 minute run. Give them a ring they may be able to tell you how to adjust it to be more suitable for your cam, or go on GT forum, someone will prob have details that you could put in yourself. Should be ok until you get it rolling roaded anyway.

Chris

[611]

Hey Chris

Its just there basic 2.0l setup and your probably right, but i figure that its taken this long to get the car to this point so a little bit of extra time to get it going and then swap cams if all ok is not too much of a problem :-)

Its not a system that they let anybody map, it has to be a proper Webcon weber dealer, and the closest to me is Kent and im in bournemouth! so might be a trip up on a trailer once its all going.

Andy

[Stev0]

okay, will I be able to fit a Y12 enem camshaft to a 19S with success?

std:

308deg duration

110deg lobe seperation

9.95mm valve lift

Y12:

288deg duration

109deg lobe seperation

11.1mm lift

the only thing bigger is the lift.. judging from the stats, it would seem as if, except for lift, the std 1.9 cam is more aggressive than the aftermarket ENEM one.. can somebody please explain this?