minto4
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| posted on 11/12/05 at 08:54 PM |
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2 Ltr Pinto Engine Tapping
Hi all,
Over the last 2 months or so i have noticed a tapping/knocking noise form the top of the engine i think. The tapping only occurs over the 3000rpm
range and only under load, it goes as soon as you lift off with the power. Today i had the rocker off and checked all the clearences of the rockers. I
am led to believe that the engine has a fast road cam (Previous owner pat) but i dont know if the clearences should be different from the standard
ones as i have set them up with these. If any one has any thoughts and can help me out please respond. Your help is appreciated. Cheers, Ben
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caber
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| posted on 11/12/05 at 09:24 PM |
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Check your timing! Could be pinking, too much advance, distributor gone iffy?
Caber
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bob
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| posted on 11/12/05 at 09:26 PM |
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Sounds like pinking if it goes when you lift off,also might be runing lean if you havnt made any other changes.
Best ask pat what fuel he was using,regular 95 octane might not be good enough.
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minto4
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| posted on 11/12/05 at 10:09 PM |
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Cheers for those replys guys. Ill try the fuel change.It does seem to have started since i had it on the rolling road down at protec in bamber bridge
the other month. The tec did alter the timing some. I think he advanced it to 14deg. the carbs were set up too as the jets were slightly out. (twin 45
dellortos) Cheers again.
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Chippy
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| posted on 11/12/05 at 11:33 PM |
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I would have thought that if you recently had it on a rolling road then the timing, and carb set up would be pretty much spot on. Just a thought but
have you checked the cam and followers, to see if you have a nackered lobe/follower. I had one go on an old Mk3 2Ltr Cortina and the tapping happened
at some weird times, but especially under load. Worth a look, I'd say.
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britishtrident
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| posted on 12/12/05 at 11:38 AM |
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Sounds like it is over advanced but unless I is really over advanced a lot I would expect it to pink rather than full blown knock, it also possible it
is a big end bearing.
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britishtrident
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| posted on 12/12/05 at 11:43 AM |
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I should add it is very unlikely to be the camshaft as this is the major down fall of the Pinto it would be at half engine speed and most noticeable
at idle to abou 2000 rpm.
Load related knocks are either combustion knock or big ends.
[Edited on 12/12/05 by britishtrident]
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minto4
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| posted on 12/12/05 at 08:20 PM |
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Cheers for your replys guys. Do think its gonna be pinking or anything with the top end. Looks like it might be the small ends on the crank. Looks
like a re-grind might be on the way, JOY. 
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rusty nuts
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| posted on 13/12/05 at 10:57 AM |
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Small ends are not on the crank. Crank has main bearings which are the bearings that the crank actually turns in, and big end bearings which are the
bearings that the con rod turns on. Small ends are at the top of the con rod through which the gudgeon pins go to attach pistons.
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02GF74
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| posted on 13/12/05 at 11:41 AM |
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The tapping only occurs over the 3000rpm range and only under load, it goes as soon as you lift off with the power.
The clue is here. I may be wrong but would not all end or rocker/cam problems would show themselves at speeds, even at idle(no load)?
It does sound like timing related - have you triedto retard your timing a bit so see if that affects or disconnect the vacuum advance - you have
checked v.a. is working and connected?
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britishtrident
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| posted on 13/12/05 at 12:53 PM |
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quote:
Originally posted by 02GF74
The tapping only occurs over the 3000rpm range and only under load, it goes as soon as you lift off with the power.
The clue is here. I may be wrong but would not all end or rocker/cam problems would show themselves at speeds, even at idle(no load)?
It does sound like timing related - have you triedto retard your timing a bit so see if that affects or disconnect the vacuum advance - you have
checked v.a. is working and connected?
Yes if anything tappet noise tend to become less obvious at higher rpm it is also quite distinct because of the half engine speed -- as this load
related that points to knock eith combustion knock or big ends.
If it were mine I would retard the timing 5 degrees PDQ and see what happens.
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