Right I have a compressor and fancy having a go at some DIY porting on a pinto head (got the Des Hamill book), just for something to do over the easter break when I cant get on with much else (still need a chassis!)

Just a couple of quick Qs though:

Will I need a long nose die grinder? Or will a normal one have enough reach on to get all the way into the ports?

Should I use carbide burrs or grinding stones on a cast iron head, guessing either will be fine?

Cheers,
David

Ive used a drill in the past and got a flexible drive for it wicked bit of kit

i have no experience of porting a head, however, IMHO the stones are completely worthless. I got a carbide burr from the snap on van when it passed my mates garage. Its like a hot knife through butter. With both compressors on it has a 100% useful duty cycle, with just one it takes some charging (probably 50% cycle). Not too bad though, as the teeth need cleaning out every now and again - i use my scribe.

Machine mart sell a angled grinder for circa £25, so maybe you could splash out and get both?!

Theres this on ebay, that should be up to the job. Just wondering mainly if its got enough reach to get all the way into the ports? (Not a clue how deep the ports are on a pinto!)

Link helps!
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=7594550039

David

[Edited on 8/3/06 by flak monkey]

I do my porting with one of these thingies from Machine Mart.




Use carbide bits for the roughing out and the mounted stones for smoothing (if they last long enough. The most usefully shaped ones are the ones that vapourise before your eyes.), and finally small flap wheels for finishing. If you can be bothered you can polish the exhaust ports as well.

Ta chaps.

Got it for £15 delivered anyway, so will see what its like. Hopefully it will do the job!

Just need a spare 2 litre injection pinto head now. Anyone got one in the coventry area that they dont want?

David

if you do a good job on yours dave i'll even let you do mine

For anyone intending having a go at porting, the long nosed ones are much better. You can direct the pressure where it's needed, and it's a lot less strain on the arms and hands, it's a lot easier getting into the ports too. Designed for the job! More expensive, but definitely worth it.
The electric ones are excellent, but even more expensive. As Stated below, the air ones use lots of air.
Cheers John

[Edited on 9/3/06 by johnjulie]

Air driven grinders use a lot of compresed air

[Edited on 9/3/06 by britishtrident]

I am aware they use a lot of air, and it will be slow going with my compressor (8cfm). If its really slow I can do it on campus using the workshop air supply

If a normal one will do the job, I am not too bothered, besides i cant afford to spend over £100 on a long nosed one or an electric one, if a normal one will do it.

David

Will be very tricky with the compressor that you bought off me Flak, you need a hell of a lot of air for die grinders.

You are welcome to borrow my electric long nose one as long as you buy a stone for it, it makes the air ones look pretty pathetic! It's variable speed too so you can slow it down when you use spira-bands in it for finishing without them exploding at you, which they tend to do with an air grinder!

Cheers for the offer Nat, will let you know if i need it anytime

Got to get a spare pinto head first to have a go at.

David

Have a look at Ebay item:
7596440330. (not mine) I've just bought one. Excellent value.
Cheers John

Have a look at Dave Andrew's site for info. on what you need to go porting.

Well my die grinder turned up today, looks ok for £15 delivered. Got a carbide burr coming as well at some point.

Will try it out next week. Says its air consumption is 5cfm @ 90psi.

I have also discovered that work has a 110V one that I can borrow if needs be

Dave Andrews website's got a lot of useful stuff on it, cheers for the link. Seems a lot of people just use an electric drill for porting work, thats got to be slow going and hard work!

Cheers,
David
Rescued attachment die grinder.jpg

Have you got an inline reg or separator. Mine used to ice up like nobodies business, even when it felt reasonable in the shed.

mines never iced up, but it does get stupidly cold - i stop more to warm my hands than to wait for air! My right angle one is proving invaluble these days, dont know how i lived without it. Just for rounding stuff off, or skimming paint off for new welding.

I used a similar tool to the one in Davids pic. Also used a small 50l tank compressor. It was slow but did the trick. Just had to let the compressor fill up a lot. Carbide cutter was the only tool that would work.

quote:

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Originally posted by Peteff
Have you got an inline reg or separator. Mine used to ice up like nobodies business, even when it felt reasonable in the shed.

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quote:

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Originally posted by DarrenW
I used a similar tool to the one in Davids pic. Also used a small 50l tank compressor. It was slow but did the trick. Just had to let the compressor fill up a lot. Carbide cutter was the only tool that would work.

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Good point Nat - i only tried to use a stone that was lying around. Knackered it in seconds cos it was wrong type. Only used the carbide cutter cos i had one and didnt have to go out and buy.

Lesson learnt - use the correct tools for the job.

I got a carbide cutter for a fiver, which I didnt think was too bad.



Got the grinding stones that came with my die grinder. Any hints as to which ones that should be used? And where to get them from?

David

PS What sort of power are you getting out of your pinto these days?

I have no idea what the power is. Havent had it tested yet. Its enough to cause traction problems at this time of year. Best 0-60 time so far is 6.4. I suspect it will be better when it dries up - i get a lot of wheel spin to get that time. I really need to practice more! Im suspecting it will be around 125bhp. It does feel like it needs a proper set up. I connected the colourtune a few weeks back after suspecting it was running rich, it was actually too weak. After tweaking it runs a lot better.

I cant remember what the correct stone to use is. Quite embarassing really as i served my time as a toolmaker!! It was a few years ago now though. Carbide cutter will be fine for roughing out. I found the small compressor helped as i could go at the head all hammer and tongs. I had to keep stopping which allowed me to prevent breaking through to the water jacket. I studied the book hard. Didnt take as mouch off as detailed in the pics. I was quite surprised just how much had to be removed. I stopped short to be safe. I got one port somewhere near then did the others to be the same. Then touched up each port to 'balance' them by feel. If you take your time its surprising how close you can get them. I didnt touch the combustion chammbers apart from removing the small step. The chambers are far harder to balance without proper kit - you can kill the performance if you do them wrong. My whole ethos was to remove sharp corners and aid airflow by blending them in. I also had to remove a load off the inlet manifold to match it to the head. Again i cut a large rad in each port using the gasket as a template.

You only need two stones, cheap enough from cromwell tools, a couple of these:


part number KEN-250-0250K

and one of these:


part number KEN-250-2200K

The ball stone will soon go oval end will then do other parts of the port nicely

You then need an expanding drum or two like these:




part numbers YRK-205-4280K and YRK-205-4190K and then some bands for them! These do a good job of tidying a refining the finish (not really polishing)

[Edited on 16/3/06 by NS Dev]

Cut a piece of old cycle innertube and roll it onto the body of the grinder. Better grip, and not so cold!
Cheers John