Pinto head porting advice....

Hi Drew,
 
"Should I fit larger ones?, can I get oversize unleaded seats? and do I get them seated and converted before I start porting?"
 
Yes try and fit the largest valves possible. But ultimately this will depend on the cam.
The valve and the area immediately behind the seat are usually the greatest restriction to the engine's ability to breath.
 
Choice of unleaded seats is usually not a problem. Unless you are racing or towing heavy loads you may not need the hardened seats. But check with the company who will be machining the seats for the valves.
 
Best to rough grind the bulk of the porting before you fit the bigger valves. That way there is less work to do after fitting the new valves and less chance of slipping and damaging the new seats. Then it is only a final blending exercise.

"Do I remove the valve guides before porting?"
 
Are you talking about shortening the length of the valve guide? Or removing the insert/liner (if already fitted)?
By shorting the length of the guide as mentioned in the book to increase flow will increase the wear on the remaining guide and reduce the life of the head. In my opinion for a street engine where engine life and reliability is required it is best not to reduce the length of the guide. Good to smooth and blend to increase flow.
 

"Finally where do you start? I'd rather start on the hardest part first so if theres a drama I don't waste too much time although that's free, more to the point expensive carbide bits and spare heads, theres only two in the shed to play with...."
 
Start at both ends of the port and then work inwards until they join up.
Port the area immediately around and behind the valve seat. Then on the head carefully mark out the outline of the inlet and exhaust gaskets you intend on using and grind out the line. Then, without the gaskets in place, trial fit the exhaust and inlet manifolds and blend the manifolds out until the joins between feel smooth.
 
Be really careful not to get too greedy and remove too much material from the inside of the dogleg of the exhaust port. It is already fairly thin there and really relies on core shift of the water jackets.
 
PeterM.

Here's a good read for you - http://www.turbosport.co.uk/showthread.php?t=152892&highlight=how%20to%20stroke%20a%20pinto
 
Good luck and keep the pic's coming
 
Matt

Cheers Matt, good thread, I've taken a fair bit from it, I now have the Vizard book on one end of the bench and the laptop on the other......
Hak073, I haven't forgotten the pics but apparently the computer isn't talking to the camera right now so once they've made friends again there will be some pics of the tools and head..... Short on that I'll just buy a new camera......
In the meantime I've been keeping a tally of my time and at hour 26 this is the progress....
Exhaust
-trimmed and smoothed the valve opening
-pocketed the shallow side
-trimmed the exit slightly on the water jacket side (as per the book)
-smoothed the sharp curve from after the valve
-and matched the gasket
Combustion chamber
-trimmed to gasket width with a little left over (as per the book)
-shaved around the valves
-and took the edges off the valve seats
Inlet, so far.....
-trimmed and smoothed the valve opening
-smoothed the sharp curve from after the valve
Still a few hours to go yet
 
Ordered a set of group 1 size valves and bronze guides, although I'm going to re-assemble what I have and get it pressure & flow tested before I pay for any machining, if that's all good, once they're in it'll be more hours yet to get them blended.......
Welding the body was easy,..... this has been the most time consuming and mind hurting job so far, I've had complete 'brain melt' a couple of times and have had to stop and do another job for a while, only to find myself mowing the lawn in even, 'maximum flowing, rounded lines' and trying not to get too close to the 'water jacket or sprinkler lines' aargh!!!!!!!!!!
Hope it's been worth it..............
 

Well the computer and camera have made up so heres a few pics......
I'm using a "flame" burr and a large round head. I've read the debates over whether polishing is worth any gains, but it does make it a lot easier to pick blemishes and check the ports against each other, using a wire brush, flappy wheels and an extension for this. Good lighting is a must, set up an old fluro on its side to shine down the ports.....    I leaned a good lesson yesterday, the cam mounting eyes are great for flipping, turning and handling the head around but the shells are super sharp and will open fingers up, won't be doing that again

I'll be at it for a few more hours today, hopefully finishing off the inlets
Cheers Drew............ 

Hello all,
Pressure test came back ok, phew I was sweating on that Valves are on the way although they cost a couple of weeks pocket money so it may be a couple more before they're fitted and I can get a flow test for a final result......
Getting ahead of myself a bit but found a guy in perth that can ceramic coat the ports and combustion chamber, from what I have read it's worthwhile.... Any opinions or experiences with this??????????
Cheers Drew

Agree with Matt, but I'd spend the ceramic coating money on the exh pipes instead .
It's great ur having a crack at porting B-)

Ok cheers guys,
Getting my head around this now, doing lots of maths trying to suss out lifts, duration, spring rates etc... still a bit at odds with valve length, need more reading.... Learning about cams, wondering if I need, or can find a hollow one? Should I get a blank and get it ground myself? Been on the piper site doing some rough pricing, anyone used them? any good?
I am getting ahead of myself on the coating, I like that it improves efficiency more than anything.... In the meantime I need to go in after work to get a quote in person, unfortunately it will come down to the price at the end of the day...........
Cheers Drew