loose exhaast seats
 

I have had two exhaust seats come loose on a 52 8rt engine. This engine gets driven a lot so maybe it is time and mileage thing. It has about 25K on it since a total rebuild. I have replaced the one seat with an oversize seat and it stayed put, but now I have the same problem on the other side of the engine. They both were on the center cylinders and it happened after pulling a long hill, 4-5 miles. I like to drive these v8's but maybe they are just to look at!
Does anyone have an easy fix? J B weld, swedge the seat in the block. I am open to any ideas, thanks chuck.

Re: loose exhaast seats
 

The quality of the rebuild is not the engines fault! This is not a common issue with flatheads (or any other engine for that matter). If the seats were not installed properly then they are going to have to be fixed. The only method I know of is to install the proper interference fit seats. Maybe some others have other suggestions.

Re: loose exhaast seats
 

Loose seats indicates a cracked block. Drill, pin, counterbore.

Re: loose exhaast seats
 

a few years ago i was given a lawn tractor that didnt run. machine was not that old but showed sigh of overheating. (single cyl. engine) had no compression so removed head to find exhaust valve seat loose and stuck under valve preventing it from closing. removed valve and replaced seat and staked around perimeter with small chisel. has held fine for 3 yrs. i would not recommend this for a flathead unless it is a last resort. i had nothing to loose with my free lawn tractor. Mark

Re: loose exhaast seats
 

I´ve stopped pulling the seats when rebuilding...if you pull and replace with the std size you have a fair chance of having them come loose.
Cutting the seats out is better for keeping the interferance fit...
5 thousands oversize seats isn´t a to bad option either...
Just my 2c...

Re: loose exhaast seats
 

The factory installed millions of valve seats without a problem (what few came out were likely from severe overheating or cracks) so your situation is far more likely to be bad machine shop work.

Re: loose exhaast seats
 

The 52 blocks never came with exhaust seats. So, Somebody installed them wrong. Unfortunately, there is no easy fix. Have a new set of oversize seats installed by a qualified repair shop.