I have an unleaded pinto head as a base for modification and am wondering how the seats are hardened. I.e. if i have gp1 valves fitted will I need to have new hardened seats fitted too?

This isnt happening until the winter, but I am trying to find out all the relevant info now so i can budget

Cheers,
David

They cut em out and drop in inserts, just make sure the inserts have a large throat area.

rgds Mark

I know how they fit hardened seats to normal leaded heads, but I was wondering if my unleaded head (not modified to be unleaded, its an injection head) will need new hardened seats putting in if I have GP1 valves put in?

It really depends on how big seat inserts are. It will have had steel inserts during production which will be slightly bigger than you valves so may cope with larger valves.

I would suggest measuring the seats and then deciding how big your valves can go without requiring new inserts. It may be that you are stuck without new inserts but hope not as it could get expensive.

Injection head only had or needed hardened exhaust seats and there is plenty of meat for the biggest valve seats to be cut. Generally you can get away with standard exhaust valves and very little modification of the port throats.
If you really must have the big numbers then 38mm valves with the throats opened to 34.5mm and blended in for the exhaust and 45.4mm inlet with the throats opened to 39mm.
Visards book is full of info but really for the full race engine, how to power tune the Ford SOHC by Des Hammill is a more street orientated book.

Its worth thinking about the cam you want to use, and whilst i can't find my Burton catalogue at the moment i am pretty sure that after you have fully flowed your head you will get no more flow once valve lift at the seat exceeds 1/4 of the valve diameter.

[Edited on 14/5/07 by snapper]

Thanks Snapper, got the books with the info in, just couldnt find any reference to the hardened seats

Itll be GP1 valves so 38.1mm ex and 44.5mm in with the ports opened out as described in the Des Hamill book. Probably fit a Kent FR33 or Piper 285 (whatevers cheapest at the time!). Full balance on the bottom end, and a fat pair of 45s should see a nice amount of power, hopefully!

Thanks again, looks like I might just get away with it.

David

The answer to your question monkey boy is YES, they can be machined to accept the big valves.

quote:

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Originally posted by david walker
The answer to your question monkey boy is YES, they can be machined to accept the big valves.

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No point in going bigger valves on the pinto heads as they are already over sized as it is.

Increasing flow is the key, and getting the angles right. The top of the inlet tract is not steep enough, it needs opening up towards the rocker gear, get bronze valve guides put in the head, slim down the tops of the valves and bobs your grandmas son.

Also, roller rockers are a good idea (see Holbay for ideas) and watch the cam overlap and lift cos it can start to become self defeating.

Tighe Cams in Australia could sort you a decent cam for Burton money, and done to your spec. Guy at work used to run a reliable 175BHP on a 2l pinto....

Cheers

Pete

quote:

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Originally posted by PeterW
No point in going bigger valves on the pinto heads as they are already over sized as it is.

Increasing flow is the key, and getting the angles right. The top of the inlet tract is not steep enough, it needs opening up towards the rocker gear, get bronze valve guides put in the head, slim down the tops of the valves and bobs your grandmas son.

Cheers

Pete

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I did a load of head work on the one i have at the moment, but nothing too substantial. All that got done was the ports and valve throats opened out slighty, but nowhere near the full amount. I am planning on opening the ports to the recommended sizes in the Hamill book (the inlet port itself doesnt need much doing to it, its mainly the throat and flattening off the turn. The exhaust side is where most of the work is required.) Including removing the old valve guides which protrude into the ports, and having them all replaced with bronze guides when I get the seats re-cut.

I am after a copy of the Vizard book if anyone has one that they no longer require? It seems to now be out of print.

Thanks for the input gents.

David

Be carefull, money is usually hard earned and don't forget most of the people on here (but by no means all) are only bar room/internet experts.

Race valves benefit not only through shape and size but also weight. Compare them when you buy your new ones.

175bhp today from a 2L Pinto is average. F2 Stockcar boys get 160 on a std engine, blueprinted and a cam.

Up to you but forget roller rockers - they offer little gain on a Pinto and are horrendous things to fit and adjust - particularly the Holbay ones. And yes, I've fitted them in the past.

Best cam for the Pinto is (IMO) the Piper A8, nothing comes near it.

Thanks David, I had no intention of fitting roller rockers etc as they are way out of my price range!

Would the A8 need any extra machining on the head (valve spring seats etc?) as I see its got 0.5" lift? I cannot remember what the limit is.

Thanks,
David

Would it not be cheaper (at the end of the day) to get the power you want by fitting a zetec? Post SVA obviously.

If you factor in the cost of the zetec (say £150), megasquirt (same again), ITBs (because I am fussy), a pair of cams (£300+) complete new exhaust (£400), new bonnet (£100) and the list goes on to get close to the power I am expecting from the pinto.

The pinto will cost me however much getting the valve seats cut will cost, plus the cost of the cam kit and valves (so say £500 in all) - the rest of the work I will do myself. Plus I also have a set of 40dcoes for sale, a complete refurbed mild tune head etc which will recoup much of the expense.

The pinto will cost me very little to upgrade, an engine swap to get close to the power will cost a substantial amount.

If I had the money I would drop in a duratec, but thats several grand over my budget.

Each to their own.

In my opinion, for a sports car application the Pinto is streets better than the Zetec. The Zetec's expensive to tune and in std form a bit lame. That said it's a modern unit, smooth usually trouble free, but at the end of the day its a saloon car engine.

The Monkey's also right about the Duratec. People talk blandly about fitting one and seeing an instant 200hp. It doesn't just happen it costs a substantial amount of cash to get there (with reliability). Prices will come down, and already we see them as taking over from the XE - but not for the budget racer yet!

Too often the Pinto is put down on here, usually by people who have no first hand experience of them. Still an excellent unit, easy to mod, not as heavy as everyone says and well within the scope of the diy mechanic.

How many "contributors" and "advisors" on this forum have actually driven a 180hp se7en? - I know I'm getting old but they can be frightening!

The A8 cam requires no seat machining but you will need the matching Piper springs. I've fitted a good many and always buy their camkit.

Thanks David, your advice has, as always, been invaluable.

Now I just need to find a piper dealer

[Edited on 15/5/07 by flak monkey]