Broken rockers Help

[Aziz]

some how 1 of the rockers on 2.5 head broke off at the valve end.
This is a exhaust rocker

I replaced this and set the valve clearance .25 and a then another exhaust rocker broke from same place as I turned the engine manually.

The cam I have fitted is a 284/272 shrick engine 2.7 eta

now I'm thnking I should replace all the exhaust rockers any suggestion why these a breaking.

thanks in advance Imran

[Martinaston]

They normaly go because the valve has hit the piston Are you sure the timing is correct ? If you have a vernier pully fitted has it come loose ?

You could have a problem with that cam where it may be fully compressing the springs

[Aziz]

I know that the valves are not hittting the pistons and valve timing is spot on.

Checked the compression of the valve springs on full lift, they are fully compressed.

So this is probably why the rockers are breaking at full lift the cam is wanting to push the valve further down but the spring will not compress any more.

Can you advise on where I can possibly get the springs that are right for this cam.

Thanks,

[Templ8e30]

You'll need to have the head machined to give the correct installed spring height. Shouldn't be too expensive, £100 ish.

Cheers,

Iain T

[Aziz]

You'll need to have the head machined to give the correct installed spring height. Shouldn't be too expensive, £100 ish.

Cheers,

Iain T

Do you know what the correct height should be for this cam 284/272?


cheers

[Templ8e30]

You'll need to have the head machined to give the correct installed spring height. Shouldn't be too expensive, £100 ish.

Cheers,

Iain T

Do you know what the correct height should be for this cam 284/272?


cheers

You'd have to take the complete head with rockers and cam to your engine builder and have them work it out because your cam will have a larger valve lift than standard.

Cheers,

Iain T

[Aziz]

Thanks Templ8e30

[Aziz]

ok guys

got a price from machine shop to get the valve seats done £120/£150.
I was told that they would do the best possible but things can go wrong

Does anyone know if their is a cam kit available for this cam its just I don't want to have to get he head machined if there is a error in calculations then I'll have to look for another head.

Imran

[hairypete]

hope you guys are still watchin this, i am havin a massive headache with my bloody engine, im onto my fourth rocker snapped in less than a year! and no i dont have a modded cam or anything, not even chipped it yet, its all just standard apart from the viper induction thing and the remus exhaust! mucho headache!!!!

now i am guessin that it might just be down to clearences, but when i take the head off (again) this weekend, is there anything else i could be lookin out for?

i will be checking for a worn rocker shaft, a block in the oil rail over the top? and anythin else that would lead to this much carnage?? any suggestions on anythin i have missed?

ok on to the plan, im going to remove the complete rocker set from my old 2 litre lump, and do a swapsies. now i have checked with my stealer parts man and he says everything is the same topside on the m20 engine. if anyone knows any different then please shout very loud!

[E30BM]

Hello. the same thing happened to my 325i Convert. It was miss firing at first. I was told cylinder no 5 was miss firing. So Bexley Motor Works in Bexleyheath Kent sorted it. They have carried out work on my other cars & I have been pleased with their work. They told me it was a ring or something that needed replacing, anyway they advised me that I should get the head gasket done as well. So I agreed & gave the go ahead. Couple of weeks later my gear box dieds.

I then got a recon gearbox fitted. Couple of weeks later I loose power whilst driving on the M11 & hear a banging sound from the bottom of the car.

I then noticed that there was gear box fluid leaking from the bottom of the car. To add to that when I started the car it sounded rough loud & I was afraid I could cause further damage if I didnt get it sorted.

I got it checked out by a BMW specialist who told me the rockers & camshaft were broker & would cost £1300 to repair. At this stage I was pissed.

I then contacted Bexley Motor Works explaining to them that what was the cause of this & why they didnt tell to replace the Camshaft from the begining when the car was miss firing.

Anyway I asked them how much for a Shrick cam for my 2.5 ? They done my a deal for previous grevence and also fitted a vernier pulley too. Coz I was told they run lumpee without a verniry p.

I could go on but I wont coz It will be a story otherwise. Any way my point is mate. Speak to the Specialist & ask them wha blow ? & if you think they charge too much. I agree however you have spent out on 4 cams already. U might be better off getting it fitted by the Specialists. U know then u got a garentee. u with me ? Anyway Bexley Motor Works are on 020 83049797. U must of heard of them in performance BMW ? Im getting tired of typing now. I lost out in being miss leaded to repairing my miss firing cam. I learned a vauleble lesson in all this. But at least now its happy day... 4 Now.

Good luck my friend & I hope this is of any use to u.