Don Terrill’s Speed-Talk

20min 2-3k break in, 3 warms ups and no drive time or rpm above 4000.

The only time I've seen that happen is when the timing is retarded so far it overheats the valve, sticks it and then shoves it up like that.

Slow timing is bad. Slow timing on break in is a parts killer.

base timing 18, 36 total, think it was one light and med spring and vac advance hooked up

BOOT wrote: ↑Wed May 09, 2018 7:11 pm base timing 18, 36 total, think it was one light and med spring and vac advance hooked up

How much timing did it have at 2500? I'd rather see 40-45 than 30 at that RPm on break in.

Was all in bout 2800 I think, deff by 3000 when the dist advance was setup before this break in.

Looks like the liner minimum finished ID was too large for the stem size allowing them to be pushed out of the guide.
This can also happen if the valves have a lot of taper in the stems or way too much stem run out on a tight clearance.

It seems some guys don't understand the reason for so many different liner choices when it comes to minimum finished ID's of the liners. They tend to not enough options based on the stem sizes they always see and use.

the other common thing is some times guys use the Classic liners with K-line tooling and they are very different in how much they hold the guide after boring. They are know to come loose without enough swedge fit and mix matched tooling can do that for you.

It gives the liner process a bad name when they are not done correctly because they are the easiest way to do guides in any head. They are also the easiest to screw up and get wrong as well

All suggestions above as well as , what was used to lube the guides on assembly?

Edit - aslo,, once apart be as carefull as possible with the liner. Have a look to see if it has overlapped itself on installation, a non checking installer can just reem or hone them to size after finding broaching dis not work properly the liner then overlaps more as you run it, comes loose and moves.

I didn't install them and don't know what/how the shop did. Also new Manely street flo valves that I left with the heads for sizing.

I've never had that problem, knock on wood. What is everybody's opinion on the tool that makes internal grooves in the guide bore that gives the liner more to grip?

tresi wrote: ↑Wed May 09, 2018 11:09 pm I've never had that problem, knock on wood. What is everybody's opinion on the tool that makes internal grooves in the guide bore that gives the liner more to grip?

While an idea that has some merit the installation of guide liners depends on 2 things.
1
the boring tool used must be compatible for use with the liners being use IE: k-Line tooling should only be used with ZK-Line liners. The guy that makes the tool is very smart and while I have not used his tool it may be a solution to an age old problem when installing liners in guides that had liners installed before.
2
If the heads had liners installed before and are just removed to install new liners the bore must be checked foe stretch. There is liners for this but again most shops don't feel that they need to be used. Wrong!!!
An other option is to use a different min. finished size liner to compensate for the larger hole to allow the liner to be sweded into place and stay there forever and at the same time allow the installer to finish the guides to the size they need to get the job done correctly and have the desired finished size before honing/reaming.

The maximum bored hole size foe an 11/32" liner is .3735" which is .030" over the standard 11/32" stem size.

There is a .036" oversize liner designed for a hole size of .375 max. guide bore size to take up the slack associated with
stretched guide bores from over broaching the guide the 1st time or worn guide bores from long term heavy/hard use.

Choose the right tooling and guides for the best finished quality and for those that did not know of the +.006" larger OD liners be sure to ask your machinist if he has them if you are having guide work done on heads that had liners previously installed to avoid liners walking out soon after you get your new stove fired up.

I saw this happen once a couple years back. I fellow brought me a set of heads that he put guides in himself. He used sum kind of adhesive that would not conduct heat thru the guide. The guides all gaulded. I couldnt check the clearance to see if he set up too tight as all were gauld slightly but I questioned his theory but no way for me to check. I do know that certain Lock Tights doesnt work greatly but ????
reed

Been meaning to respond but life, thx for the comments. The liner didn't work out, that 1st pic is kinda deceiving. Lots of shavings & play tho!