351C factory heads, can valve guide cracks be repaired by complete removal of the iron guides and pressing in thick-wall bronze guides?

Spring side

Seat side

I've got a much better valve guide for you that will save these heads. I'm checking with the supplier now to see if he still carries them.

I'll update as soon as I get an answer.

You will like LOVE these.

They really made a mess of them.

I hate to think where all the fragments of cast iron went.

Is the cracking on the top of the heads a serious issue? Couldn't he press / machine out the guides, and then remove the thin cast material? I can't see how that cast housing adds A LOT of strength.

I would be worried about the cracks inside the port, though. I wouldn't want a chunk coming off the intake side.

I'm just asking, to trying to learn.

Thanks.

Rocky

Best guess- the P.O hammered new guides in from the top down, at room temp. The very thin flashing left from boring out the oem guides then cracked. Very hard to avoid if flashing is left behind. Disregard- does nothing for strength but remove broken bits as much as possible. FWIW- I drive them in from the chamber side using an air gun while castings are hot. Cut for .502 guide seals, sometimes the guides crack as well if driven from the top.

quote:

Originally posted by Rocky:
Is the cracking on the top of the heads a serious issue? Couldn't he press / machine out the guides, and then remove the thin cast material? I can't see how that cast housing adds A LOT of strength.

I would be worried about the cracks inside the port, though. I wouldn't want a chunk coming off the intake side.

I'm just asking, to trying to learn.

Thanks.

Rocky

The person who did these guides has no idea what is required to do them right.

What I am trying to get is current availability of the solid manganese-bronze guide.

It is .502" od. To install them, you machine off the rest of the top of the cast iron guide that "the other guy" left. (Must be a Community College shop class graduate?)

Then you bore the guide hole to .497 and then hone it to .499. Then you press these in from the top until the shoulder stops it.

The top has a ridge so it can't slip through. The seal sits on top and you trim the length in the port to where you want them.

Easy-peesy!

The guy who sells them is Ted Standhope, I believe and email him at

engnbldr@engnbldr.com

Here's a picture of one of my spares.

This one is for a 427 Ford. The one for the sb Ford is the same except for the valve stem hole of 5/16". This one is a 3/8 stem.

These are the same guides that Edelbrock and Trick Flow use. As far as I know, he supplies them from what I understand but it's been awhile since I bought these?

If he doesn't have them, TFS has the same ones. You can get them there or even from Edelbrock.

They are so simple to do you can do them yourself in your own shop.

These are the guides that you want. They are so easy a retard, a Chevy guy, a potential xxx candidate could do them?

Now - don't go "full retard" on us, Doug, or you'll need more cowbell.

Thanks for the info.

On the intake side the answer is definitely yes. I've seen guys do it intentionally. There's very little risk.

On the exhaust side I'm a little hesitant about complete removal of the iron guide inside the exhaust port, exposing the bronze guide to the exhaust gases which can run up to 1000 degrees F. I have no experience however.

Press in iron guides could be used on the exhaust.

I would suggest removal of the cracked metal is paramount, a crack in the exhaust port could run anywhere and do who knows what damage eventually.

Ok guys, thanks for your answers.

In fact we are on the same line, I was thinking the same remove the thin stuffs on the top and have a basic guide with a shoulder and the other side have a tapper which come gently to my valve diameter, I have EPN valves and the portion supposed to be outside of the guide has a smaller diameter for flow I guess. So in order to avoid sharp cross section changes I would see a tapper here. If I go in porting I will take all opportunities to do the best flow.

Panteradoug, thanks for your help I will email your guy see what he proposes to which price.

But I am pessimistic, first I don't find what I want and when I find it it is pretty expensive. So if the part is so simple I was wondering about asking my machinist to do them I would just need to buy a 11/32 reamer. I just need to confirm that I can go with bronze.

Another problem I found, if you look to the guides they are driven to far in the direction of the top, so when the valve is opened there's nearly no room for the valve seal which almost all cracked and felt as small pieces into the oil pan.

And I am nearly sure the drove the guides from the bottom to the top because it would have been to complicated to do from the top with the thin casting lips. And as they probably were not exactly aligned they've cracked everything, when they start driving it.

I have made few measurement this morning, the intake press fit length with a "flat roof" would remain as 21 mm on intake side and 27 mm on exhaust side. If I assume the 0.502 guide this gives a 1.75 ratio on intake (press fit length = 1.75 diameters) and around 2 for the exhaust.

Last thing, about the sealing, there is an option which is using some modern valve seals, as you advised to me, but, with old one and broken one my engine managed to get very worn guide with I guess plenty of lube, two questions : is there a break-in procedure with new valves + new guides, and isn't it better to stick with old style seals ?

Some more pictures :

Look to this disaster :

Casting top (just need to be cut away and do a little chamfer) :

Measurement :

Intake press-fit length :

Exhaust press-fit length :

Have you considered the price differential between the cost to machine your old heads with new parts vs a set of upgraded modern aluminum heads?...Mark

Hi Mark, I'm in France, I can look but things cost twice the price when arrived here (customs .. shipment … ) …

quote:

Originally posted by Aus Ford:
Press in iron guides could be used on the exhaust.

I would suggest removal of the cracked metal is paramount, a crack in the exhaust port could run anywhere and do who knows what damage eventually.

Aluminum heads use bronze guides on both intake and exhaust. What is the problem with that?

The remainder of the cast iron guide in the ports can be machined out and the bronze guide stands alone as the complete guide.

As long as the crack does not continue into the port itself and create a coolant leak, that's how you fix these heads. The plus side is you get increased air flow around the area that was formally occupied by the cast iron guide support.

Go look at some aluminum heads. See how they changed the ports and how the bronze guide was installed.


Use the teflon "PC" type seals. The guide I showed you "locks" them on so that they won't pop off. That's what that series of fine grooves is for.

http://www.summitracing.com/pa...VH9LSK_qgaAnav8P8HAQ

Engnbldr got back to me and said that he permitted his stock to run out and not replace them.

You are going to have to get the guides from one of the aluminum head manufacturers like TFS or Edelbrock. They are the same guides as far as I know.

I paid $4 per guide. I only have one set of each left for me, so I can't sell you any.

Pantera doug, can you show me your guides ?

+ some measurements ?

I will take them if they can fit, or the can be used to create a model if I do not find the remaining 14 ones.


FYI the stock valves were FORD, I think they were change as they have only little seat wear, and we can see on them how rough the machining was. I took the EPN ones, the are much more smooth and I did a quick polish of the steam with belgom they are even more smooth, there's a big triboligy equation here.


Jérémie

FORD valve

Ford / EPN / EPN polished

quote:

Originally posted by Jérémie:
Pantera doug, can you show me your guides ?

+ some measurements ?

I will take them if they can fit, or the can be used to create a model if I do not find the remaining 14 ones.


FYI the stock valves were FORD, I think they were change as they have only little seat wear, and we can see on them how rough the machining was. I took the EPN ones, the are much more smooth and I did a quick polish of the steam with belgom they are even more smooth, there's a big triboligy equation here.


Jérémie

The pictures I posted are them. Well almost. The small block guides are the same external dimensions but for 11/32" valve stems.

I don't have any to give or sell you. I only have one set of each and those are for me.



My heads are all installed and I have no pictures of them or the ports to show.

Very little of my projects are documented like everyone now does with digital cameras. I never thought anyone else would be interested in seeing the results.

The shaft is .502" od. The od of the shoulder is .530". 2.381" is the overall length. The length that presses into the head is 1.943". The tip that projects into the spring is .437".

The total length you are supposed to trim after they are installed in the head.

They are designed for a press fit from the top. You hone the head to .499", then press them in. Probably .500" is ok too.

Then after they are installed you run an 11/32" reamer through them to make sure the hole is round.

Then just assemble your valve train to them.


I am using the cut back stem EPN stainless valves also. They are high quality and sometimes repackaged as Faria.

Faria doesn't make anything anymore. They repackage existing valves that meet their quality expectations.

They are a little on the heavy side but there isn't much alternative to that except a titanium valve.

I'm not sure that is adviseable to use since the valve stems on those will tend to wear out fast unless you use the teflon coated ones?

With those you need to worry about where the teflon is going to wind up?

Sorry pantera doug I did not read correctly your post.

I have sent an email to your contact hope he will have some left, at 4$ it is a great deal.

Thanks for the dimensions, I'll ask a machinist for the price.

Jérémie.

He told me yesterday he has no more and permitted his stock to run out.

He is in the state of Washington and is on Pacific Coast Time.

The Edelbrock and TFS guides look the same. Probably there are other aluminum heads that use the same.

I don't know where the manufacturer of the guides is. Israel and Argentina are two of the possibilities.

These parts now get purchased in bulk from wholesale manufactures worldwide.

quote:

He told me yesterday he has no more and permitted his stock to run out.

Ok that means that the stock is already off ? sorry I did not understand again, I am not english native speaker.

So the super deal a 4$ is dead, that's pretty bad for me :/

Probably. Buono e morti. Good and dead.

You understand English better than some of those who have it as their primary language. Why apologize?

It is I who should apologize to you for not being explicit enough.

I do try. Everyone knows that I am very trying?

quote:

Originally posted by PanteraDoug:
Probably. Buono e morti. Good and dead.

You understand English better than some of those who have it as their primary language. Why apologize?

It is I who should apologize to you for not being explicit enough.

I do try. Everyone knows that I am very trying?

Ok that's good if my english is not totally weird lol …

Your guy has answer to me, he seems very nice, that's a pity that he does not do this anymore, he gave me some phone numbers.

That's cool but … writing some post on the internet is one thing, speaking on the phone is another one !! lol

quote:

Originally posted by PanteraDoug:

Use the teflon "PC" type seals. The guide I showed you "locks" them on so that they won't pop off. That's what that series of fine grooves is for.

http://www.summitracing.com/pa...VH9LSK_qgaAnav8P8HAQ

Great educational thread!
Just a comment re these seals you are linking to. These are viton seals, and need very precise diameter to install. The teflon ones has a spring to hold them tight and are more forgiving.

I like the PC teflon seals. You just push them on. The series of grooves that you see on the bronze valve guide are there for extra grip for the seal to hold tighter on to.

a beautiful crack :

.502" cast iron guides

Alex's Parts is your friend!

http://www.alexsparts.com/valv...375-x-502-universal/