Can I assemble my own heads?

7173Mustangs.com

Help Support 7173Mustangs.com:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Joined
Feb 14, 2016
Messages
524
Reaction score
2
Location
Clover
My Car
72 Mach 1, Q code 351CJ, 4 speed.
I am going to have the heads cleaned, checked and machined for screw in studs.  Is there any reason I cant order the correct spring kit for my cam, buy new valves and locks and assemble the heads myself?

I am going to disassemble them before I take them in.

 
Yes, you can assemble them. You'll need to check the assembled valve height to make sure you'll have seat pressure from the valve springs, or the opposite, not enough height, which could result in valve spring bind. Are you having them install hardened valve seats, or touching up your seats? In any case, the new valves need to be lapped in.

Make sure your machinist checks for any sign of valve recession if you're not having new seats installed. You'll also need to have your machinist check valve guide clearance. You don't want to get your heads home and have sloppy stems. Also have him surface the heads so they're nice and flat. And, talking about flat, if you don't have to bore the engine and take it to the machinist, run a straight edge around on the block surface to make sure it is flat.

You'll also want your machinist to machine the guides for real seals.

 
Last edited by a moderator:
the machinist needs the valves to do the valve job properly and if he knows what he is doing he will set the valve stem height at that time.

the valves do not need to be lapped in but it is definitely a nice extra touch and is easy to do. if they need to be lapped in, the machinist did not do the job properly or the valves are crappy.

i never surface heads unless they need it. the machinist can check to see if they are flat.

 
Last edited by a moderator:
what about spring height and seat pressure?  If I get the matched springs to the cam Im running will I have the spring height and seat pressure needed or is this something I will have to shim to get right even if I do have the matched springs?

What about valve locks and stem seals?  I am going to a one piece set of Ferrera's with the single groove instead of the multi groove valves.  Is there a specific valve lock and stem seal I need to order?  Im asking this since there is multi grooves does that mean the locks and seals fit in the multi grooves??  Hope that makes sense.

 
The distance from the valve retainer to the valve seat is your valve assembled height, with the valve seated (valve head firmly against the seat). The valve springs you buy have to match the height, so you have the correct seat pressure and don't wind up with spring bind. If the height is too much you'll need to get shims for the seats. If the height isn't enough you can get retainers that add 0.050" to the height, if that isn't enough the seats have to be machined for proper clearance.

The seals have nothing to do with retainers or valve grooves. The umbrella type seals just fit over the stems and move with the valves. The positive seals fit over the end of the valve guide, remain in place, and the valve stem slides up and down through the seal, and require machining the top of the valve guide for the seal to fit on.

I would recommend you find a good engine building reference before you attempt to assemble your own heads. This is a critical component, failure of any part of it can result in destruction of the engine.

 
Last edited by a moderator:
There are better places to economize, the valvetrain is not one of them. Have your machinist assemble the heads, he has the tools to ensure the springs are set to the correct installed height.

 
what about spring height and seat pressure?  If I get the matched springs to the cam Im running will I have the spring height and seat pressure needed or is this something I will have to shim to get right even if I do have the matched springs?

What about valve locks and stem seals?  I am going to a one piece set of Ferrera's with the single groove instead of the multi groove valves.  Is there a specific valve lock and stem seal I need to order?  Im asking this since there is multi grooves does that mean the locks and seals fit in the multi grooves??  Hope that makes sense.
the correct valve springs are typically close to the right length or just need a thin shim. comp cams has many different ones and theirs are decent for most street apps.

as far as the valve locks and spring retainers go, it can get quite complicated. it starts with the valve lock groove in the valve then works outward from there. Many ferrea valves use a special lock. these locks are available with 2 different tapers on them, so the taper on the id of the spring retainer needs to match the taper of the valve lock, and the bottom side of the retainer that has the steps in t needs to fairly closely match the id of the springs.

i told a person how to build a very high hp mopar engine and i used ferrea valves and lightweight manley spring retainers and their nextek valve springs and this took a couple calls to both ferrea and manley to determine exactly which parts would be compatible and nobody had ever built their heads like this because they just didn't know about these parts.

 
Last edited by a moderator:
I'm thinking that I should just bring the bare heads and new valves, springs and retainers to the machinist and have them do everything.  Unless I find something not right in the bottom end I'm not planning on rebuilding that since it was already done a few years back.  So the money will be all in the valve train.

Ive got to figure out what screwin studs and guide plates I need so guess I will be giving SUMMIT a call.

I'm calling the machinist this morning and see if I can get an idea of what they are going to charge me.  I like to do things myself and love to save money but the last thing I want is to end up with a boat anchor!

 
I'm thinking that I should just bring the bare heads and new valves, springs and retainers to the machinist and have them do everything.  Unless I find something not right in the bottom end I'm not planning on rebuilding that since it was already done a few years back.  So the money will be all in the valve train.

Ive got to figure out what screwin studs and guide plates I need so guess I will be giving SUMMIT a call.

I'm calling the machinist this morning and see if I can get an idea of what they are going to charge me.  I like to do things myself and love to save money but the last thing I want is to end up with a boat anchor!
You won't save more than $20.00 by assembling the heads yourself because it takes less than 4 minutes for a shop to assemble each one and you would need to buy or rent a valve spring compressor.

 
Last edited by a moderator:
Back
Top