I recently brought my head to a machinist for check and rebuilt. I order one piece stainless steel set of valves for both heads intake and exhaust. The valve come with the regular 2 angles. Should i go with the 3 angles valve job on the new set with the seat or just give my seat 2 angles? How much they will flow better with 3 angles or it's minimal ?

Also the heads will be mill just to make sure they are straight. My block was also deck at the minimum, just to clean and make sure the block is straight. I'll be using roller rockers with a stud conversion kit. I also order hardened pushrod stock lenght but since the block was deck and the head mill, did i have to use some shim underneath my rockers or i'll be ok like that ? maybe the adjustment on the rocker will take the difference.

This is my first rebuild and don't understand valvetrain tech very well.This is a 400 with aussie head. Any help will be appreciate.
Serge.

 

Hey Serge,

The 3 angle job is a great idea and will improve your flow at the valves, I ran across an artcle that explained with detail but i cant seem to find it.. anyways, This usually entails placing different angles on the valve seat itself, increasing the flow of combustion gases and improving horsepower and torque. A 3 angle valve job is the cutting or grinding of 2 angles on the seat and valve. So you have 3 angles, the first below the seat, the one that makes contact with the valve sealing it and the 3rd one above the valve seat, so as soon as the valve starts lifting air/fuel mixture will imediatly start to enter the combustion chamber...

You should have ordered your pushrods after the rest, so you could measure your geometry and be sure. You can still get away by adjusting your rockers since only 0.010" are normaly removed when surfacing a head for straightness...

 

Thanks hollenjoe, your probably the only one who reply with a answer with good detail, i like that. What is the next available pushrods lenght +/- ? How can i know if i have a good geometry, and if not, how do i mesure it ?

Just to let you know. I have seen a guy, with a 2 1/2 hours drive from home but on my way to my week job, shop who told me they have a new cutting tool so they can made LIKE 5 angles valve job. One's for the seat and the rest is like a curve on the valve. Never heard that before but he claim it's better than 3 angle.

He's a young guy(but with experience to me just the way he was looking for a better cam with comp ratio, piston height, transmission set up...), but he told me i should go with a step up with my cam(i have the xe-256). Since i change my mind from the stock style .030 piston(after he told me i was down the hole too far)for the zero deck tmeyer piston for aussie heads. Tim piston are allready in the block now...with maby a better cam choice?

 

Yerah a 5 angle job would even be better , thats if your valves have enogh meat.

If you already have teh stock length push rods you should try them as you stated, mybe you could get away with the adjustable rockers, there is a speacial tool to measure it, as i remember theres two ways pushrods are measured, from tip to tip called the real measurement and from where the straight part endes to where the straight part ends on the other end, dont remember exactly how they called it.

Sincer you have your 400 on your light mustang (so do i), and a nice compresion i would go a bit higher on the cam, like the xe262h..

 

3 angle is considered a standard.....4 or 5 angle is where the goods are at!

 

Going from a 3 angle to 5 you will never notice a difference on the street. I'd reserve that for a all out race motor.
You can either buy or make a adjustable push rod out of a old one to check length. Put a light checking spring on the valve so the lifter doesn't compress while you are checking. Find out the compressed thickness of the head gasket you are going to use. Put the head on with shims, (feeler gages work fine) of that thickness under it. You don't need to torque the head, just tighten it down firm with a few bolts around the shims. Put some sort of compound on the valve tip, blueing, white greese or something. You can eyeball it if the engine is on a stand. Put the valve train in with the push rod adjusted to the stock length and turn the crank till the valve goes through it's cycle, make sure the lifter plunger doesn't compress while you are turning the crank. The pattern should be centered from top to bottom on the valves tip. It will take a few times to get it right. Measure the push rod once you have it right. You will now need to add the lifters preload to the figure. For hydro lifters add .020-.040. I always use .020. Call Summit, Jegs, etc. and order your new length. If you are useing guide plates, get hardened ones.

 

What about from 2 to 3 Mark a.? The engine is on the engine stand and i used the stud converssion kit from crane cams with 1.7 roller rockers. Lifter plunger doesn't compress ? I put my lifter in engine oil for 2 days to remove all air trap inside, that's good? I know i have to wait 30 sec to let the spring push the lifter, is that what you mean by plunger doesn't compress ? Thanks a lot Mark a., i'm learning.

 

When the valves checking spring starts to compress it can/might start to compress the lifter's plunger. If this happens you won't get a accurate measurement on the length.