jmattley
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Worth doing on a series 3 petrol you reckon? Could get a stage 2 head but could probably do an ok job myself with a die grinder. From your experience, is it something worth doing?
Ports and polishing etc etc...
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ATO
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Did my 2.25 5mb with a dremmel..made a big difference. Used to go up this hill near me in 2nd, after porting & polishing went up in 4th!
jmattley
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Thats' what I thought. Did you just buy a big set of dremel tools or did you use proper porting tools? Also, how much did you take off? Did you basically polish it or just a bit of tickling?
ATO
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I didn't really take much off at all..all I did was take out the casting imperfections (there are loads on these old heads) so it was all smooth and just polished till it shone! You need to take the valve guides out to do it properly. Could've taken loads more off the ports than I did and still made a dig difference.
I just used a bog standard dremmel & tools.
I just used a bog standard dremmel & tools.
G-man
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you don't want a shine...........air will move much faster over a slightly rough port, port pollishing is a very 80's tuning method and in the mid 90's it was found the (due to the laws of fluid dynamics) that i higher gas flow can be achieved though the use of a rough port(should have a satin look to it), it would be hard to explane the theory over the net as i would need to use diagrams.
just taking out the casting marks will give you a power boost, after that you could think about re-shaping the ports (oval works well) i'm not sure how close the waterways run to the ports to alow the re-shape tho so i would advise against it as you could bugger your head if you break through a waterway,
other things to consider are, re-cutting the valve seats as yours will be pitted to buggery, re-shaping the combustion chamber(not much you can do with the **** kidney shaped design it comes with tho) and pollishing it(eliminating potential hotspots) skimming the head to give a higher compression ratio beyond that there isn't much else you can do with one of these heads
don't forget to clean up the inside of the inlet manifold when you do the head as this will have casting marks too
just taking out the casting marks will give you a power boost, after that you could think about re-shaping the ports (oval works well) i'm not sure how close the waterways run to the ports to alow the re-shape tho so i would advise against it as you could bugger your head if you break through a waterway,
other things to consider are, re-cutting the valve seats as yours will be pitted to buggery, re-shaping the combustion chamber(not much you can do with the **** kidney shaped design it comes with tho) and pollishing it(eliminating potential hotspots) skimming the head to give a higher compression ratio beyond that there isn't much else you can do with one of these heads
don't forget to clean up the inside of the inlet manifold when you do the head as this will have casting marks too
Soloby Rob
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G-man
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so only things like Honda vtecs and bike engines????? sorry mate you have lost me there, better gas flow will benefit all engines in my experience with mk2 escort rally cars (2.1 pinto engines max 7400rpm for longevity) a ported head was the most important job all of your power on a N/A engine comes from your cylinder head, poor design leads to poor power, the bottom end mods give strength top end mods give power, i will concede its not as important on a forced induction engine but this doesn't have a turbo or a supercharger
jmattley
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Exactly, that's why you can buy ready made stage 2 heads which everyone who buys them says it's worth it.
Soloby Rob
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There's no point in porting and polishing unless you go the full hog, bigger valves, high lift cam, gas flowed inlet and exhaust manifold together with a performance exhaust system and decent carbs, increased compression ratio, up rated crankshaft, up rated distributer etc etc.
We're talking about a S111 here :wtf:
ATO
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Obviously Turners and loads of their impressed customers would disagree with you there.
nonsense
Turners can't buy enough used heads to refurb these days, the demand for their stage 1 and 2 heads is that great, and i can guarantee they aren't all being fitted onto totally reworked blocks
Soloby Rob
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nonsense
G-man
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i am no longer entering into this debate, as a member of the motortrade and having worked in motorsport (preping mk2 rallycars as well as grp N fwd rally cars) i feel my input could be valuable but if nobody is going to listen to me i feel i am wasting my time, if anyone would like my advise on this subject ask
ATO
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Davec
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Land Rovers, when used as intended, do not need highly tuned engines, so Land Rover made no attempt to do so. This means there is massive potential for tuning with not too much effort.
I seem to recall that in the late 80s there was some one comping a "standard" 2 1/4 who was getting around 140 BHP.
I certainly know several people who have attacked them with a Dremil and basically just removed the worst of the casting marks and made noticeable differences.
Please stop sulking G-Man. there are people listening to you, because unlike some you seem to be talking sense.
I seem to recall that in the late 80s there was some one comping a "standard" 2 1/4 who was getting around 140 BHP.
I certainly know several people who have attacked them with a Dremil and basically just removed the worst of the casting marks and made noticeable differences.
Please stop sulking G-Man. there are people listening to you, because unlike some you seem to be talking sense.
I have to agree with you, all engines benifit from these mods, although to perhaps a lesser degree. I too was involved with motorsport and modded a few engines and vehicles.
It's not quite as simple as grinding out ports and bigger valves tho, some engines are blighted with ports too large to start with.
I found, and its one of the major mods is to match the manafolds to the head. Take a drill and drill through the manafold into the head, but not into the water jacket, fit silver rod which makes sure the manafold always fits into the same place, then mark the two surfaces and grind out the surplus metal until they match perfectly.
In relation to the valves, you need to see if the breathing charactistics of that engine requires bigger valves, however you can improve the flow if you grind away the section of valve guide that sticks down from the inside of the port, but it reduces the life of the guide since it's shorter and can't do the job as well. I also cut 5 angles onto the valves giving an almost curved profile rather than the sharp restrictive one. Continue onto the seats and use a radius cutter which will give you curved seats then much better flow.
I have seen many heads fooked by maniacs with grinders, you need to know where to take metal off, how much, and have a means of measuring the amount, usually with fluid.
In relation to the timing most are miles out and the only way to get it correct is by fitting a vernier pulley or offset dowels, and off course the distributor fitted standard is ****e so a decent one is also required.
Then a camshaft and followers and valve springs, and it goes on forever depending on what you want to spend, but the more tuned it becomes the more unreliable inevitably it becomes, with engines that wont idle below 1500 rpm and often a bastid to get going.
Oh one other easy mod, lighten the flywheel, fokin tonnes of metal surplus here so there is, probably fokin tonnes on the landie con rods aswel, and the crank, then off course there is the balancing bit.
rustyrhinos
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Deffo agree with that one, makes a good difference, and when you think about it makes a lot of sense. Plenty of people enlarge head ports without thinking that the bottleneck will then be the manifolds. I have a had a play at home brewed head mods...shaved just under half a second from my 1/4 mile time so was quite impressed with that.
A higher compression engine, depending on application, isn't always a good thing!
Disagree and agree with you there. In my opinion it's a bit of a waste of time on a Land Rover engine...but thats not to say you need a high revving engine to have the benefits of a better flowing head, not at all. If you do it right, head work is one of the best modifications for performance on a N/A basic engine (as long as you match the air/fuel supply and exhaust gas exit to the better flow of the head of course).
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