I need to adjust my clearances this week but was wondering whether people aim to be bang on the book values with their clearances or whether its better to aim for the bottom of the tolerance range? ie; if your value is 0.40 +/- 0.05mm - do you go for 0.35mm to keep the gap to a minimum?
Reason I ask is that assuming the larger the gap the more "tappety" these engines run which is a big complaint from many here and if you find your clearances are out and you raise them, to me that would suggest you would naturally end up with greater tappet noise or is this not really how these things work?
Does getting the clearances "bob on" book spec somehow make for a smoother quieter tappet? Youd think it might given that Fiat would want them leaving the factory with the lowest possible tappet noises but it doesnt seem logical to me to increase the gaps to get them to spec.
I swear I am about 5 years too late getting onto this forum........
Last edited by clarkster; 10th March 2014 at 13:21.
The tighter they are the quieter it will be, but you risk valve not sealing correctly and being properly seated which will eventually burn the valve out. Anywhere around 0.45 will be fine. I think i even pottered around in mine for a few days with clearances as tight as 0.22 whilst waiting for a few shims in the post, didnt do any harm
Right OK as i thought on the noise then - not what i want. Not having done this before Im a bit sceptical about veering away from the fiat specs too mcuh but you reckon 0.45 is OK if thats the case I dont really need to be so anal about some of the shims then.
my readings at the weekend were taken twice on saturday and a 3rd time sunday averaging out to;
no 1 EX 0.43 (0.07 below 0.50 book spec)
2 IN 0.35 (0.05 below 0.40 book spec)
3 IN 0.34 (0.06 below
4 EX 0.45 (0.05 below
5 EX 0.48 (0.02 below
6 IN 0.38 (0.02 below
7 IN 0.35 (0.05 below
8 EX 0.42 (0.08 below
i think two lobes have lost their point - think its no2 and possibly no. 6
Was going to say make sure cams not worn, I have a cam from a sporting in the garage in good condition
There all within tolerance , number 3 is .1 under .
Sent from my iphone .
Ive already got another GT cam that I might stick in there thats good with no.2 just ever so slightly rounded on the point but much better than the one ive got. but then ive got to start all over......
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