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setting valve clearnace order
Posted: Wed May 26, 2010 8:35 pm
by hotrodder13
ordered a manual but i need to know what order to set the valve clearance i know to set intake to 0.12 and exaust to 0.15
searched on here but cant find it
thanks tom
Re: setting valve clearnace order
Posted: Wed May 26, 2010 8:40 pm
by bmcecosse
Any order you like - but most would start at #1 and then follow the valve opening sequence along to minimise engine turning! take the plugs out to make the turning easier. Do you not have a Workshop manual ?? You do know to follow the rule of 9 ? ie When #1 valve is open - you adjust # 8 (1 + 8 =9) #2 when #7 is open (2 + 7 =9) etc etc . Good idea to torque the head down before you start - if it has been off recently.
Re: setting valve clearnace order
Posted: Wed May 26, 2010 8:54 pm
by hotrodder13
thanks didnt know about the rule of 9, and the head hasnt been off in a while, if a valve gap was closed could this cause poor perforamce
thanks
Re: setting valve clearnace order
Posted: Wed May 26, 2010 9:04 pm
by bmcecosse
Yes!
Re: setting valve clearnace order
Posted: Wed May 26, 2010 9:11 pm
by alex_holden
hotrodder13 wrote:ordered a manual but i need to know what order to set the valve clearance i know to set intake to 0.12 and exaust to 0.15
By the book it's 0.012" for all valves.
Re: setting valve clearnace order
Posted: Wed May 26, 2010 9:14 pm
by bmcecosse
But the book didn't have unleaded petrol! The 15 thou on exhausts is a much better idea..........
Re: setting valve clearnace order
Posted: Wed May 26, 2010 9:42 pm
by hotrodder13
well just finished settin (one exaust vavle was nearly shut and one intake was to far open the reset were almost right
filled the carb dashpot with oil and bottom end speed and sound is so much better but it gets to 80 then wants to die and the backfiring is gettin worse (just backfires when i take my foot off the pedle) what could cause this, tryed pulling choke out and no change
thanks tom
Re: setting valve clearnace order
Posted: Wed May 26, 2010 9:44 pm
by bmcecosse
When you say 'back firing' - do you mean explosions at the exhaust pipe - or spitting back through the carb inlet ?
Re: setting valve clearnace order
Posted: Wed May 26, 2010 10:09 pm
by hotrodder13
sounds like im shooting someone with my exhaust pipe

Re: setting valve clearnace order
Posted: Wed May 26, 2010 10:42 pm
by bmcecosse
Well that suggests an ignition problem - raw petrol is going down the exhaust pipe un-burned when the ignition fails - and then is ignited when the ignition comes back on! Look for bad connections - but could just be a faulty spark plug - try a plug swap first.
Re: setting valve clearnace order
Posted: Thu May 27, 2010 12:50 am
by mikeysmorris
just a thought could it be an air leak in the exhaust system, but has ron says could be plugs it will show up any faulty ones at high rpm, best of luck with it, regards Mikey
Re: setting valve clearnace order
Posted: Thu May 27, 2010 6:52 am
by hotrodder13
i dont have any spare plugs so ill have to order some, and i checked for holes and found nothing
thanks
Re: setting valve clearnace order
Posted: Thu May 27, 2010 8:12 pm
by hotrodder13
decided to change the pump to see if it will sort it (got a free one),
will my clearance be diffrent with a diffrent cam in i know its hard to tell cause i dont know what cam is in but i got speaking to an old machanic and he said he had it on 15 itake and 20 exhaust when he had a diffrent cam in his 1275cc
Re: setting valve clearnace order
Posted: Thu May 27, 2010 9:37 pm
by bmcecosse
You only need to increase the gaps when using daft high lift rockers. As long as the 'lift' is generated at the cam - the 12 inlet/15 exhaust is fine.
Re: setting valve clearnace order
Posted: Thu May 27, 2010 9:48 pm
by hotrodder13
kk dont think it has that but got double valve springs

Re: setting valve clearnace order
Posted: Thu May 27, 2010 10:08 pm
by bmcecosse
Oh dear, double valve springs - more wear and tear!
Re: setting valve clearnace order
Posted: Thu May 27, 2010 10:12 pm
by hotrodder13
whats wrong with them
Re: setting valve clearnace order
Posted: Thu May 27, 2010 10:18 pm
by bmcecosse
Unnecessary wear and tear on the valve train - you shouldn't really rev a 1275 much over 6000 unless it has been strengthened/balanced. So single springs are fine - and also absorb less energy opening and closing the valves!
Re: setting valve clearnace order
Posted: Fri May 28, 2010 6:55 pm
by hotrodder13
ok it came with them on anyway, do u know how much psi a standard fuel pump has

Re: setting valve clearnace order
Posted: Fri May 28, 2010 8:48 pm
by bmcecosse
Very little psi - it's not a pressure pump. But it should be able to pump half a pint of petrol into a bottle in 1 minute.