porting the pinto head DIY style

[5tox]

After reading a few of the books and following some tips on the net ive decided that im gonna have a go with my dremel,

im gonna practise on my carb head before playing with the injection head


firstly i opened up the exhaust port to the same size as the gasket






and then tried to smooth back that massive restrictive valve guide, i have just tickled the edges with the dremel creating a kind of triangle shape





how much should i remove from here? i know its restrictive but ive also read that it helps with heat dissapation


then i tried to smooth out that big bulging section in the exhaust port giving a smoother curve as opposed to a quite jagged edge
The pics arent very clear but as you can see i have just created a smoother curve halfway up in the middle, i wanted to check i was doing the right thing before taking the curve all the way from the floor to the roof (leaving the original material and just cutting out a small section of the middle makes it easier to show what im trying to acheive)






any advice tips or tricks are appreciated, im no expert just a DIY enthusiast whos interested in engines

[5tox]

had another go today, i think im on the right lines...

first i started to remove the sharp endge leading down from the chamber into the valve seat





Section 2 is the step in question and step 1 shows how the edge has been removed giving a smooth edge down into the valve seat

im not quite sure what section 3 is, its like a cut out in the valve throat, does it serve any purpose or should i try and smooth it out as far as possible removing the step?


original valve guide




and after a bit of work

[MK1_Oz]

Hows this going? I have been considering taking the die grinder to an old head myself.

[5tox]

to be honest mate ive been side tracked and its taken a bit of a back seat

will crack on with it again soon and get some pics up, not too sure if i was heading along the right lines with it but its only a cheap carb head so not got much to lose

id like to compare my work against standard carb and injection heads on a flow bench

[dollie007]

Search for my post "cautionary tale for DIY porters..." I ground through into the water jacket on my first head, but I was we'll pleased with the results at second attempt. Car is now built but I havn't had it running or rolling roaded to comment if I actually achieved anything!!
Oliver

[5tox]

couldnt find it buddy, you dont have a link do ya?

id be interested to read it

ta

[dollie007]

I'll try and post a link in the morning, I assume you have vizzards book or something similar?

[5tox]

yes i have read the book, there were some parts i diddnt quite understand though i.e talking about venturi's etc...

the only bits i really latched onto was the fact that you should open out the exhaust port to match the gasket and remove the big obstructive valve guide where it protrudes out into the inlet port
it said that you should leave most of the valve guide in the exhaust port as it helps with heat dissapation so ill probably just smooth the edges

[dollie007]

Hopefully this will work...

http://www.turbosport.co.uk/showthre...autionary+tale

Im no tuning expert but I did find that as a novice i worked on 3 of the cylinders but left one untouched so that I had a reference point, on the first head i just kept taking a bit out of each and it was unclear to my inexperienced eye where I was taking too much. I straightened out the exhaust port by cutting myself a piece of thin'ish perspex at just less than the width Vizzard specified as safe max (26 or 27mm'ish IIRC) and kept sliding it into the port taking a bit at a time from the side with the kink in. I found this particularly effective and meant i never took too much or risked the water jacket. It wasn't the fastest technique but worked for a beginner!! Graham and a couple of others on here are very, very knowledgeable and will no doubt give you fantastic tips on specific areas if you ask.
Oliver