a and a+ valves interchangable?
Turbo Mini Forums

hi, i have an austin 1300 gt head that i am modifying. obviously it has larger inlets and double springs, but was wondering about the exaust valves

someone here said the a ones are crap. the ones in my head have pits visible on the faces of the valves. this is a concern, as running a turbo i fear that these pits will pick up hot spots.

i have a load of 1275 a + heads about, are the valves a direct swap. Will the 1300 gt caps and springs be compatable with the a+ exausts? im away at the moment so havent had chance to look, but are a+ valves tripple groove collets?

in all, can i change the a ones for a+?

i need to regrind a few of the seats again as a couple of valves leek when i tested with petrol, so changing valves about is not a problem

many thanks

Why not shell out on some nice MS stainless race ones? OK £11 each but they must be good for a few extra bananas and they are new unlike 20 year old A+ ones.

Edited by Jay#2 on 23rd May, 2008.

because iv just spent about 1k on panels and other little bits and pieces. im rebuilding completely near enough, and really cant afford to keep spending a few quid here and a few there, on things that arent essential. i will probably be upgrading engine componets etc in the future, but as i understand the a+ valves are excellent quality?

Just for reliablity, worth buying. Don't want your 1k's worth of panels stuck on the side of the road because a valve let you down.

heed the advice above.......... the valves are intechangable as long as you use the same caps and collets for the A series which are single groved

and the triple A+ groved tops and collets

the A series valves are a tad taller overall but that isnt an issue
hope this helps

The pits on the valve faces will need to be ground away. This is the reason for reseating valves, and the reason why valve grinding paste is a waste of time.

A valves are soft, I would not use these in a "high output" turbo engine. Inlets are OK as these are cooled by the inlet charge. Exhaust, NO.
Get some Minispares exhaust valves or if you're after lifespan, get some decently backcut A+ exhaust valves. They're GREAT!

minispeed charged 33.64 for the 4 stainless exhaust valves 9.62 for the collets 6.75 for the top caps and 9 for the bronze guides .all plus vat ,he gave me a 10 percent discount by deciding i must be on minifinty forum i think even though i wasnt ,and told him so ,he was very freindly about it all .

Edited by robert on 24th May, 2008.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

if you want any second hand good A+ valves give me a shout

cheers but iv got a load of cylinder heads in the garage/shed.

the pits on the exaust valves are are on the face of the valve, some look to be 1-1.5 mm deep. Il be using a+ ones by the looks. its a budget engine build. will only be running 8psi. as the a valves are longer, will i be able to use the a series double valve springs with the a+ valves, collets and caps?

im not being tight but its expensive work building a mini, even when sourcing bargains and doing the work yourself!

yes the springs are interchangable use the inner spring loctars for doubles as well which the inner spring sits on

i will do. so are the a+ better than the a valves?

Yes, they are much harder and the stems are chrome plated. On inlets it doesn't really matter.

cheers. il have a look at swapping them next time im home. many thanks