Compression ratio concerns

[miller]

Some of the other guys chime in on this one.

Though what I see, almost looks like the original cast guide busted, and without removing the upper part, reamed it, putting in a guide as a easy fix. Might be able to tell, by looking at the other end of the guide. Sure, it can be repaired (replaced), but that depends one how far you want to go on it...how bad you want to use those heads.
Probably already know this...those steel spring shims...used if the spring seats are cut, to get the springs back up to installed height.

 

[IQ52]

If that was an exhaust guide I might say don't even worry about it. But me being 1/2 way around the world and it being an intake, I would machine the broken portion down to the spring locator pad. Then, as I believe that is a .500" diameter 3/8 guide, I would just use one of these seals on it.........

https://www.summitracing.com/parts/cca-521-1/overview/

 

[RRSweden]

If that was an exhaust guide I might say don't even worry about it. But me being 1/2 way around the world and it being an intake, I would machine the broken portion down to the spring locator pad. Then, as I believe that is a .500" diameter 3/8 guide, I would just use one of these seals on it.........

https://www.summitracing.com/parts/cca-521-1/overview/

Thanks! Not too terrible news than. Phew...
I feel comfortable to follow your advice regarding stock iron heads!

 

[khryslerkid]

Thanks! Not too terrible news than. Phew...
I feel comfortable to follow your advice regarding stock iron heads!

You can check out my garage for the tools I had for redoing my 452 heads. You'll have to order the cutter for a .500 dia valve guide.

http://www.forbbodiesonly.com/moparforum/showcase/reworking-452-heads-for-new-springs.4648/

 

[RRSweden]

You can check out my garage for the tools I had for redoing my 452 heads. You'll have to order the cutter for a .500 dia valve guide.

http://www.forbbodiesonly.com/moparforum/showcase/reworking-452-heads-for-new-springs.4648/

Great work! Looks awesome.
I would imagine that kind of cutter would not work smoothly on this shattered stud though... I think I'll try to carefully mill it down, leaving as much of the guide thats nessecary to put a smaller diameter seal to it.

 

[Garys1969RR]

Looks like the top of the valve guide broke off at some point. Possibly when they were installing the bronze guides? They came from the factory with the cast iron guides, and most builders bore them out and install the bronze inserts. So the heads have been upgraded already! No! Don't get a new hobby, look at this as an opportunity to learn! And pray for our resident head expert to give you some "guidance". LOL

 

[Garys1969RR]

I think it's best to leave as much of the original cast iron as intact as possible. This adds some support to the bronze guide. You may want to round off the sharp edges with a file, and just install a factory original type umbrella seal on that valve. Then you can avoid any machine work which would prob crack the casting further. Is that an ex valve?

 

[RRSweden]

I think it's best to leave as much of the original cast iron as intact as possible. This adds some support to the bronze guide. You may want to round off the sharp edges with a file, and just install a factory original type umbrella seal on that valve. Then you can avoid any machine work which would prob crack the casting further. Is that an ex valve?

No. it's an intake.
I worked on the iron today with my Dremmel, and got it smoothened down, so a right sized seal (0.50") will probably seal it.

(I left the camera in the garage, I can show you pics tomorrow)

 

[miller]

Have you checked the ID of all the other guides? Not worth fooling with, until you know how they stand.

 

[IQ52]

You can spend a whole lot of money on your heads.............

Or you can fix them up and just get them to run. You'll have to decide.

Your least expensive route is to do your fun porting, do a valve job, surface mill the heads, install the stock type umbrella seals (on all the valves, even the one with the broken guide) and assemble the heads with the proper spring installed heights.

 

[IQ52]

When I disasseblied the new 915 heads THIS shows up under one spring... View attachment 378303
What to do? Can I use it as it is, and just prey, or can I fix it in any way do I start to look for another hobby.... ;)

It looks like they replaced just the one guide for some unknown reason. I doubt the spring pockets were machined.

The spring shims were probably added to increase the spring installed pressure and they probably added them just because they saw somebody else do it after they did a valve job and thought, "Well, we sunk the valves some so we need a shim." .......And never actually checked a damn thing.

It would be easier to see if there are more replaced guides if we could have some pictures into the ports from the combustion chamber.

 

[RRSweden]

It looks like they replaced just the one guide for some unknown reason. I doubt the spring pockets were machined.

The spring shims were probably added to increase the spring installed pressure and they probably added them just because they saw somebody else do it after they did a valve job and thought, "Well, we sunk the valves some so we need a shim." .......And never actually checked a damn thing.

It would be easier to see if there are more replaced guides if we could have some pictures into the ports from the combustion chamber.

I can take pictures from the combustion-side of the heads. I noticed that the cast iron had a crack even there (on the boss in the port) on the same valve guide.

Every spring had a shim under it. How do I measure spring installed height?

 

[RRSweden]

...and what tells me which measurments I want? The camcard?

 

[IQ52]

You set them up using the tool in this gentleman's post.
http://www.forbbodiesonly.com/moparforum/showcase/reworking-452-heads-for-new-springs.4648/

Comp Cams recommends the 911-16 valve spring for the XE268H camshaft. If you set them up at 1.88" + or - .020" you'll be good enough for that cam. Hopefully whoever did the valves the last time got them fairly close already. The whole thing is a delicate dance that we've learned over the last 40 years that isn't that easy to teach over the internet.

 

[RRSweden]

You set them up using the tool in this gentleman's post.
http://www.forbbodiesonly.com/moparforum/showcase/reworking-452-heads-for-new-springs.4648/

Comp Cams recommends the 911-16 valve spring for the XE268H camshaft. If you set them up at 1.88" + or - .020" you'll be good enough for that cam. Hopefully whoever did the valves the last time got them fairly close already. The whole thing is a delicate dance that we've learned over the last 40 years that isn't that easy to teach over the internet.

Thanks! I will look in to that post. Trying to learn as much as I can here
I reallise it's hard to "teach" via the internet, to a complete rookie, but I really appriciate all your input!

 

[Garys1969RR]

Wow! That is some nice looking port and head work, IQ 52! What is the outside diameter on the bronze guides in those heads? It appears that they are slightly larger in the casting, than the tops are. I guess the tops have been machined to accept the .500 I.D seals.

 

[IQ52]

On those guides it is .502" in the head pushed into a .500" hole. There is a ledge that is .565" that goes against the spring pocket face and the seal surface is .530".

 

[miller]

IQ52 is absolutely on the mark. Nice looking set of heads!
Those heads, RRSweden, are a great starting point, to make a great set of heads. As long as their crack free in critical areas. But, it does take a hand that knows exactly how to do it. They can easily be turned into scrap iron, too.
Need to make a game plan for 'em, and decide how far you want to go. Even bringing them back to 'stock' will probably take a little work.

You cannot get a spring height measurement, until the valve seats are cut/done, since part of the measurement includes installed valves, and spring retainers.

 

[RRSweden]

I don't think I can afford to have the seats replaced and cut. My plan was to use copper grinding paste in two grit-steps.
My budget is really the biggest block here.
Of course I could wait and save up, but the goal is to be a part of the "Street Week" this summer. It's swedens answer to your "Hot Rod Drag Week".

Now i'm off to the garage to get some pics of the heads

 

[IQ52]

IQ52 is absolutely on the mark. Nice looking set of heads.

Why thank you. They are the very heads used in these dyno tests.

http://www.forbbodiesonly.com/moparforum/threads/pops-440-is-near-ready-to-dyno.64775/