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Sept 26, 2010 13:47:57 GMT
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I've been told about this modification by a friend and plan to do it to my Reliant 850 head when it comes back from the engineering shop. Advantages (if you believe the hype) are a more efficient burn giving better fuel economy, more power, greater resistance to pinking, lower running temperatures etc and it can be a very cheap mod, theres a video on youtube of someone doing a decent job with a hacksaw blade and a small file. By cutting the grooves you do lose a bit of compression but I was looking to do this slightly anyway as I'm supercharging but I guess normaly a skim would bring it back up. Any views or experience of this mod?  www.mgccars.com/groove_101.htm __________________ |
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Sept 26, 2010 14:20:42 GMT
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I remember a long thread on Migweb.co.uk (vauxhall forum) about these a couple of years ago. It was a discussion by some guys who really know their stuff and was quite in depth and interesting. The fact that I remember it something like 2 or 3 years later must say something! Not sure how long the Migweb site stores stuff for but would be well worth reading if possible.
Just had a quick look at the site you linked to. I think the guy might be rather over-exaggerating the benefits and is wearing rose tinted glasses, particularly to his claims of cleaner oil, lower EGT, better sex life etc. The style of writing reminds me of snake-oil style miracle cures rather than a scientific investigation. There's lots of speculation and guess work but no proper evidence.
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Last Edit: Sept 26, 2010 14:30:15 GMT by awattam
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Sept 26, 2010 14:36:41 GMT
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Sept 26, 2010 15:32:56 GMT
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Thanks for the links!
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Sept 26, 2010 16:02:07 GMT
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Never heard of it before so I'd take it with a pinch of salt. No engine tuning book I've ever read has ever mentioned it.
What I will say is you're introducing a sharp edge in the combustion chamber which will promote a hot spot and can cause pinking. You're also affecting the flow on a critical area of the combustion chamber that has been deliberately put there to cause 'squish' which is one of the mechanisms that creates a nicely combined mix ready for combustion.
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Sept 26, 2010 16:22:33 GMT
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sounds like rubbish to me, one point, it makes a hot spot for precombustion, whatever the other advantages are they would be far out weighed by this in a hard working engine (turbos and whatnot)
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Sept 26, 2010 16:27:10 GMT
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After having a couple of Reliant heads crack between the valves the last think I'd want is a "man made" groove as it'd be a great starting point for a crack elsewhere  Paul h |
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Sept 26, 2010 16:32:04 GMT
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Hot spots were what sprung to my mind too. Also, by introducing a sharp cut like that, would it not promote cracking of the head in the long term? Especially in areas like valve seats and between valves.
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Sept 26, 2010 18:27:32 GMT
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I believe that the swedish volvo modders do this a lot, and as I understand it it does help to reduce pinking.
Lewis
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Sept 26, 2010 18:49:38 GMT
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If it was so good, wouldn't the manufacturers do it already?
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Sept 26, 2010 19:14:43 GMT
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If it was so good, wouldn't the manufacturers do it already? extra costs, unproven over (for example) 20 years. most manufacturers wouldnt touch it I'm wading my way through the articles and links now looks an easy mod., but I'm not sure how long a standard head gasket would last unless modified to suit |
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Last Edit: Sept 26, 2010 19:15:24 GMT by Autofive
Someone just shot the elephant in the room. |
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Sept 26, 2010 20:08:58 GMT
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you could allways buy a turbonator!  |
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1995 Toyota rav-4 1978 Kawasaki Z650B
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will
Posted a lot
Posts: 4,023
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Sept 26, 2010 20:15:20 GMT
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Interesting, I'd like to know the how and why which may stop me being as skeptical. Please report back your findings A5 ;D
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Sept 26, 2010 21:09:25 GMT
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Hmmm, i've not seen that idea before, which means none of the race car owners i know are doing it, that would lead me to think it does not work, anything that that simple that leads to extra power would appear on race engines pretty early on.
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Volvo back as my main squeeze, more boost and some interior goodies on the way.
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conrad
Posted a lot
Here to fix your cabin.......
Posts: 1,678
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Sept 26, 2010 22:09:48 GMT
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I cannot imagine doing that to be a very good idea, for the reasons mentioned already. It seems as if it's supposed to be something anyone can just do with basic tools (after all a hacksaw was mentioned)... but i know if it was an engine i was investing time and money in, i want prefessional, tried and tested headwork, not someone cutting weird grooves into it. I can't see it having a positive effect that would outwiegh the possible gasket, head weakening, and hot spot problems
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Sept 26, 2010 22:23:01 GMT
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Just reading that guys page was enough to put me off. I've seen too many people review stuff like ecotek valves and fuel saver magnets writing stuff with that kind of blind enthusiasm.
The swirl will perhaps be increased, but not hugely (there isn't that much volume in the grooves) but you'll get hotspots and stress raisers in exchange.
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