View Full Version : Wanna laugh? Stock car Tuning!!!!
Blackie_No1
27-04-10, 12:02 PM
I was speaking to a boy yesterday, who tried to tell me how to tune the 1.4 engine.
He said to forget about skimming the head(not that i mentioned it) but said skim the cam box!!!
He said once this is done nothing will touch me??? though im thinking thats because the valves will be flying out behind me!!!
What are your thoughts on this "expert" stock car advice??
mk1nova_rich
27-04-10, 12:16 PM
theoretically it gives more cam lift, but the valves probably wont seat properly when "closed". either way it sounds like a pikey mod lol
its a valid 'mod'
Its basically the same as having a reground camshaft (but the opposite way round lol).
by lowering the cam in relation to the rockers you open the valve earlier than if it was left in std position, and the ultimate lift is more and the valve will close later. It will fully close because you wont be able to skim off enough from the cambox to completely squash the hydralic lifter down.
The only real drawback is you cant easily work out what skim will make what change to the effective cam duration.
nova-taken
27-04-10, 02:53 PM
one of the guys i know done this mod on his 16se with a kent ast2 cam.
all was well until he started it and squashed valves due to skimming too much off!
Fail!! lol
the problem is that you are not actually making more lift on the valves by skimming the cam carrier, because you are not actually changing the distance between the top of the lobe & the bottom, thus it is a waste of time effort & money............
good point lol. But it will increase the effective duration.
some of the cam companies actually specify that the cam carrier needs skimming for some of their cams, I think newman do for sure.
He said to forget about skimming the head(not that i mentioned it) but said skim the cam box!!!
Nothing abnormal about that thought.
Blackie_No1
27-04-10, 07:27 PM
I dunno, sounds wrong to me, surely the lifters won't fill up fully and therefore cancels out any possible benefit?
I dunno, sounds wrong to me, surely the lifters won't fill up fully and therefore cancels out any possible benefit?
Youve gotta think, in stock hatch or stock rod (one of the other?) the engines have to be bang on standard, so a non noticable & possibly pointless engine work gaining minial (arguably, any?!) gain in power is always worth a try.
nova_saloon
27-04-10, 07:32 PM
lol i just like the fact he was like nothing will touch you! i can think of alot of things that will touch you and then probs rape you. but it is a valid mod, Just not one id try myself
Blackie_No1
27-04-10, 07:37 PM
I can't see how it would make any benefit. The cam is always touching the lifters in normal circs, with the cam box skimmed the lifters will be partially depressed and will not fill to thier full capacity, therefore reducing the full lift that they would normally achieve?
peester
27-04-10, 07:46 PM
aye i guess its a using stock parts only -mod/bodge
they run solid lifters on the stock rods they rev to about 8500 rpm!
Blackie_No1
27-04-10, 08:21 PM
Yea I thought that too but he said he was still running the hydraulics!!!
the lifters DONT move the valve (persay).
they are merely the pivot for the rocker to move on when acted on with the cam
comptoncj
27-04-10, 08:36 PM
My uncle skimmed his cam box on his 1400 engine in his sport, he was running an ast8 cam he did tell me why but i have forgotten but it made the angle the cam hit the pads at different thus upping performance. I have also heard that when you skim an 8 valve head you should also skim the cam box the same ammount.
craig green
27-04-10, 08:53 PM
I would sooner pay for some proper motorsport driving tuition than bother with all that aggro.
I would sooner pay for some proper motorsport driving tuition than bother with all that aggro.
you'll struggle to find a truer sentiment
as i've already stated, it is not a useful mod..... if the cam hasn't altered, then it is of not benefit whatsoever. if the cam timing was out, a clever enough bloke could easily weld the peg hole up & redrill it so it looks stock... that sort of stuff is why motorsport engines cost so much
Blackie_No1
28-04-10, 01:43 PM
yea, i gotta agree unless someone who has actually done comes on and convinces me otherwise, its all very well sayin "i know my dogs uncles brothers owner did it on his car" but noone has been able to say they have seen or felt the benefits if any....
again, even if the lifters are just a pivot point there is going to be no further lift gained....
I stand by the no extra lift, but the actual TIMING of the valves opening is changed... this could be the little extra needed to gain over someone who hasnt done it.
but dont let engieering and physics get in the way of you wanting to berate this person lol
stu, the amount of alteration to the timing will be tiny, and the relationship between the inlet & exhaust cams won't alter at all, so i would be fascinated to see if there really was a measureable gain, that couldn't be optimised by using a vernier pulley & then swapping to a modded 'standard' one.
i know that when my old 1.2 jumped a tooth, so the cam was advanced, it ran like a sack of the proverbial
Powered by vBulletin® Version 4.2.5 Copyright © 2025 vBulletin Solutions, Inc. All rights reserved.