I am building a 427 race motor and want to install 11/32 valves. Who makes a bronze guide for these valves? I ordered some Manley guides from Summit thinking they were the complete guide, but they are just a sleeve to go inside the existing guide. Pro and cons of these sleeves? I would rather replace the entire guide if I can find them. Thanks! Bill napa219

I am building a 427 race motor and want to install 11/32 valves. Who makes a bronze guide for these valves? I ordered some Manley guides from Summit thinking they were the complete guide, but they are just a sleeve to go inside the existing guide. Pro and cons of these sleeves? I would rather replace the entire guide if I can find them. Thanks! Bill napa219
=
You never ever want to replace the entire guide on a BB unless it is absolutely necessary.
The guides are not concentric & you will usually end up moving the seat about 4 feet when you have to change the guide.
Well, maybe not quite 4 feet,,,, :D
but any unwanted movement of the seat is usually not a good thing,,
Either use the thick wall K-liners (my choice) designed to install 11/32" valves in the heads or use a .502 guide that goes into the original one after machining.
Whatever your machinist is comfortable with is the one to use, I don't tell other shops how to do their job :noway:

But I have been known to offer "suggestions",,,,,, :D

Take the heads to a "reputable" machine shop and have them install new 1 piece cast guides INSIDE the existing OEM ones. DO NOT let them remove the originals under any circumstances.

This a "simple & straight-forward" deal that will end up saving you much grief. Seen it too many times in the past, "ruined" heads. You don't need the
"bronze" guides/liners, but it would be your option. The above procedure can be done the same way 1 piece "bronze" also.

The replacement guides measure .343" I.D. x .502" O.D. and are simply
"pressed" into the original guides after machining them with a core drill and reamer. This sole procedure "fixes" all the guides AND "steps" them down to the SB stem size in one operation

Thanks, Gary in N.Y.

P.S. At a minimum, you don't want to "disturb" the original exhaust guides in the early BB castings. A very high percentage of the shops around today aren't aware of the "can-of-worms" that can be created by improper removal of them. They are "directional" when removed/installed. Removed incorrectly and you end up having 2 "junk" castings.

Thanks for the help I guess I will be returning the liners to Summit. Thanks Again!! Bill napa219

Thanks for the help I guess I will be returning the liners to Summit. Thanks Again!! Bill napa219

I assume what you have are the Manley 42161 "sleeves" ??
These are the K-Liners
Ask your machine shop if he approves, some do not like the liners
I have been using them for over 25 years & have excellent results with them but they have to be installed correctly, broached & honed to size.
The other cravat is you have to use quality valves with any bronze guide be it a liner or the .502 "repair guide"
Crappy stem finish will kill the guides in short order.
My first choice in valves would be Ferrea, good stuff :thumbsup:

They are actually Manley 42158 are these usable?

They are actually Manley 42158 are these usable?

Most people in this business today have gotten away from the Manley valves due mostly to the fact that they "break" when they come into hard contact with the pistons.

This may sound like it's what's supposed to happen, but it's not. A "good" valve will take the "hit" and bend, but not break. It will remain in the chamber where it belongs.

My own personal belief is that Ferrea's least expensive valves have as much or more quality than most expensive "brand name" pieces. The only units leaving here that see Manley valves anymore are the BB 100% appearing resto's that use the factory cast iron "oval-port" heads. I use Manleys here due the fact they have the 2.125" x .343" SB intakes that fit the BB heads. Ferrea's has this size scheduled to hit the marketplace soon.

Thanks, Gary in N.Y.

P.S. Most recently had a Cloyes "True-Roller" break "through the lights" at around 8200 RPM. Ended up with 14 bent valves and 2 good ones, BUT, not a single broken one and NO major damage to the unit!! Had Ferrea's inside.

They are actually Manley 42158 are these usable?
Yes, that is the correct ones
The one I listed is for 5/16 stem valves in an 11/32 guide, sorry about that.
Had to go look it up as I don't get my liners from Manley
One thing though, both of these liners are assuming you have pretty good guides to start with which is very doubtful.
If not you need to use a different one that is has a thicker wall or just use the .502 "repair guide.
The deal with the .502 guides is there are very few heads they will not fix
All of this stuff needs to be done by a competent machine shop as stated above though ;)

BB guides have to be removed by pressing/knocking them out from the bowl to the stud side, right??

And then installed from the stud side, again, right??

pdq67

BB guides have to be removed by pressing/knocking them out from the bowl to the stud side, right??

And then installed from the stud side, again, right??

pdq67

Hi Paul, how you doin'?

Correct you are, on the early BB heads and specifically on the exhaust's! It's my understanding the later one's were different, but I've never done one of the late ones.

Thanks, Gary in N.Y.

P.S. Just to clear it up some, if you take them out from the spring side to the chamber side, you will crack the heads. They will not come out without ruining the casting. These guides, the exhaust's, are "stepped" and pass directly through the water passage.

Hi Paul, how you doin'?

Correct you are, on the early BB heads and specifically on the exhaust's! It's my understanding the later one's were different, but I've never done one of the late ones.

Thanks, Gary in N.Y.

P.S. Just to clear it up some, if you take them out from the spring side to the chamber side, you will crack the heads. They will not come out without ruining the casting. These guides, the exhaust's, are "stepped" and pass directly through the water passage.

=
Partly correct,
They will not crack the head but they certainly will ruin it
On the early heads the upper part is .004 bigger than the lower part
On the later ones the lower part is .004 bigger & if you push the guide the wrong way it will "broach" the small part of the hole & new guides will not seal.
According to AERA the change was made mid year 85 but with GM never assume anything ;)

So,,, you need to check before removing the guides.


Here is an excerpt from an AERA TB,,
===================

Exhaust Valve Guide Caution On
1965-98 GM Big Block Engines

These engines' valve guides were not intended as a replacement item from GM.
The guides were located into the head castings after the head was cast and
the exhaust guide is "water cooled".
The water-cooled guide also has two different size press fit diameters. Adding additional confusion to the matter, they also switched the location of the larger diameter sometime in 1985.

To determine which outside diameter guide you have and which direction to
remove an exhaust valve guide, the following procedure is suggested:

Drive the guide no more than .250" (6.35 mm) toward the valve spring side of
the head and stop. Then, measure the newly exposed area of the guide
OD next to the spring pad.

If the measurement is .620" it is the first style guide. To remove this
style guide, continue driving it toward the valve spring side of the head.

If the measurement is .616" , it is the second style guide. To remove
this style guide, you must drive it the opposite direction toward the combustion
chamber side of the head.


=============COMPLETE AERA BULLETIN==================
Exhaust Valve Guide Caution On
1965-98 GM Big Block Engines

The AERA Technical Committee offers the following caution for exhaust valve
guides on 1965-98 GM big block Chevrolet engines. Through the many years of
use of these engines, GM has modified cylinder head castings numerous times.
One of those modifications involves the method of repair considered for
exhaust valve guide service.


These engines' valve guides were not intended as a replacement item from GM.
The guides were located into the head castings after the head was cast and
the exhaust guide is "water cooled". The water-cooled guide also has two
different size press fit diameters. Adding additional confusion to the matter,
they also switched the location of the larger diameter sometime in 1985.

Several types of concerns exist for terming exhaust guides unusable, including
excessive wear or coolant leakage. Either a new OEM casting or an oversize
stem diameter from GM serviced excessive valve guide wear or coolant
leakage. To meet customer satisfaction however, aftermarket manufacturers
have offered "replacement" valve guides for these engines. If the guide is
leaking coolant around the outside or inside diameter, the entire guide may be
replaced.

To determine which outside diameter guide you have and which direction to
remove an exhaust valve guide, the following procedure is suggested:

Drive the guide no more than .250" (6.35 mm) toward the valve spring side of
the head and stop. Then, measure the newly exposed area of the guide
OD next to the spring pad.

If the measurement is .620" (15.748 mm), it is the first style guide. To remove this
style guide, continue driving it toward the valve spring side of the head.

If the measurement is .616" (15.464 mm), it is the second style guide. To remove
this style guide, you must drive it the opposite direction toward the combustion
chamber side of the head.

Guide Diameter Direction
@ Spring Pad to Remove
After Moving .250" Valve Guide


.620" (15.748 mm) Valve Spring Side of the He
.616" (15.464 mm) Combustion Chamber Side Head

Some AERA members report many years of successful valve guide repair by
using conventional "universal" replacement guides, both thin wall liners and ½"
outside diameters. That type of repair is made only when the water-cooled
exhaust guides are not leaking.

Thanks Mike for the long info!!

pdq67