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2.2 Cih, Stage 2 Head On Twin Su Carbs. What Cam?


mantaboy89
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Hi,

Presume your going to use the car as a fast road car. If thats the case I would suggest either a Piper OPBP 285 or a Kent OP244, these have a range of 2500 - 7000 rpm. Both need solid followers ( standard 1900cc Manta ) and Kent suggest you use their stronger valve springs. As for power it all depends on the rest of your engine spec but if its properly set up and rolling roaded you should see around 160+ bhp, but as I say its down to a complete package.

Lamchop77 is the man who knows about these engines so he may have a different suggestion.

Regards

John

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Mantaboy

When you say stage 2 what do you mean? Are you running std valves with porting or just bigger valves? Makes a difference for power output.

Don't bother with the 214, it will only be like a std cam in a 2.2. CIH larger capacity motors soak up duration so you can go wilder on the cams. My 2.2 used a 244 cam, you need to get the pistons pocketed to accomodate the higher lift. Think the pockets were 6mm deep and 48mm dia cut to give plenty of clearance. You will need to use solid lifters and also Kents valve springs.

With std pistons,2.0 ported head, 244 cam n bits plus twin 48's n lightened and balanced mine was putting out 175-180bhp.

You will also need to uprate the clutch as the std one will not take the grunt!!!

HTH

Chris

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Should be able to reach that sort of power then. 2.2 heads flow about the same as a ported 2.0, but mine has 46/41 wasted stem race valves in so give or take a bit they should be about the same. SU carbs are really good but you will need to get them set up properly.

Also do not waste money on a 4 branch tubular manifold for the spec of motor your building, the cast one is fine, its what i ran on mine. The twin downpipe was a standard size but did link to a straight through 2.5" system.

I would also advise a vernier timing gear if funds allow, it can make quite a difference depending how much has been skimmed off your head.

HTH

Chris

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Hey Chris

What about the ENEM cams? They said that the Y12 would work fine on the 2.4 with standard pistons as full lift was not at TDC, but just after, so setup properly they would be no issues with clearance?

This is the info they sent to me. And was for a head that had not been skimmed

"There is no problems with the pockets as long as timing is correct. If you want to be 100% certain you can adjust 0-clearenc on the cyl 1 inlet valve, put a dial gauge – or use a vernier – so that you can measure the inlet valve opening at TDC when the engine is in the overlap position. It shall be opened 2.,1 mm, +-0,4 mm.

Clearance is only critical when the engine is in this position, at full lift the pistons are close to the bottom position.There is no problems with the pockets as long as timing is correct. If you want to be 100% certain you can adjust 0-clearenc on the cyl 1 inlet valve, put a dial gauge – or use a vernier – so that you can measure the inlet valve opening at TDC when the engine is in the overlap position. It shall be opened 2.,1 mm, +-0,4 mm.

Clearance is only critical when the engine is in this position, at full lift the pistons are close to the bottom position."

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Never used ENEM as they're not easy to get hold of in this country. I've picked up cams dirt cheap, just keep yours eyes open on the forums. I can order Kent stuff quickly and the engines that i've used them in have always produced good power.

The 2.5 engine is prob going to get a High speed racing Mega 10 cam (think thats what its called!!!)

I would never go off what the manufacturers tell you, yeah its a good guide but they work on the principal of an unworked engine at std tolerances. Being a machinist i know about tolerance build up, you can easily be 0.5 to .75mm off either way with a depending on whether your plus or minus.

Just as an example the 2.3 engine i have, i decided to measure the position of the piston in the bore every 10 degrees to have the info for developing a cam specific to the long stroke 2.3. This was so i knew where the piston was relative to the top of the block so the valves could be kept open as long as possible. Thing was it was at different heights coming up the bore than it was going down. I measured it 5 times or so.....still the same. It was 0.7 ish mm differnt at one point. Couldnt figure it out so asked the guy that does all my engine bits and he just said " oh thats probably your crank thats not centred in the block......dont worry about it" But it shows what a little bit out in one area can make a big difference elsewhere in the engine so always do the dry build using plasticine.

HTH

Chris

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you wont save anything going valver route i know i have been there.

just buy it bit at a time and use standard stuff till funds allow.

you will still have a good strong engine with standard cam and lifters.

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Just about to put the head back on mine with standard cam in so was going to do a dry fit and make sure all was ok when turning it over by hand before i get round to starting it up. Will make sure i use the plasticie method. Then when i know its all working ok its in with the ENEM cam and new lifters, rockers etc.. and another test fit! Might get it running this year :-)

Andy

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Mantaboy

How much have you got to spend? Depending on what you come back with i could probably help with getting the pistons pocketed.

Got a set i had done for my old race engine but they're worn on the ring gaps, kept them for ref for the pocket depths and they had plenty of clearence. My engine guy did them for me so if you wanted i could get a price for getting a set of 4 done, if the price is ok you could post them up and i'll take them down. Let me know.

As for power with a std cam, std power mate!!!! They were about 115bhp, porting might give you 5-10bhp depending on how good it is.

Best thing for you might be to put in a 234 cam, it'll only be a fast road ....ish cam but a 2.0 will give 160bhp with twin carbs with that fitted and a ported head. So working on that the 2.2 will be giving more grunt plus the head is gonna be slightly better so you could see a shade over 160bhp. The SU's could make better power or less but you will only find out when its rolling roaded. The 234 cam usually clears standard pistons on a 2.0, but the 2.2 has bigger cut outs so it should be fine......but i would still check. Also at 160bhp the std clutch should be ok.

HTH

Chris

Chris

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  • 7 months later...

I've used Valvoline racing 20/50, good oil and doesn't foam up at high rpm, duckhams Q (proper old school oil) 20/50, seems to be thicker when hot than the valvoline so might be better for pressure problems. Try using a classic 20/50 spec oil as they did change the specs a few years ago and the oils definately ended up thinner.

Have you tried putting a spacer (3-4mm) behind the spring in the pressure relief valve, worked on a engine of mine!

Cheers

Chris

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Also do not waste money on a 4 branch tubular manifold for the spec of motor your building, the cast one is fine, its what i ran on mine. The twin downpipe was a standard size but did link to a straight through 2.5" system.

HTH

Chris

What is inside diameter and length of std twin downpipe?

2.4exhaust manifold have two 52mm (2,04inch)outlets.Do You reckon copying Mantas B twin downpipe length with 52mm in to 58mm(2,28inch) should work fine for mild 2.4Cih? Or is it worthwhile to know Frontera/Omega downpipe lengths and copy them?

2,5inch endpipe could be too much with stock camshaft loosing low grunt.

Edited by Lesis
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  • 2 weeks later...

My 2.2 was running 180bhp (ish) and I was using the 2.0 gte manifold and downpour, that opened out to the 2.5" single box home built exhaust. Guy at the rolling road said it flowed really well! It's usually the first 3 feet of the exhaust that make the difference, the manifold and downpipe are about that so I would just try it and see.

Hth

Chris

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