Flathead valve peening?

Mac_49

Mac_49

Member
Saw this on another site thread and figured someone would know what's going on here?


Head.jpg
 
Under IKF rules this was allowed but the number of "peens" was limited to I believe 8. Fluid Weld (sold by Goodsons) also worked and helped to prevent a leaky seat, I also used it when installing new valve guides. -- Chuck
 
WkA RULE.... 701.13 VALVE SEATS:Valve seats must meet stock specs, and can be replaced. Seats must have one angle only, 30 degree intake and 45 degree exhaust. Seats MAY NOT PROTRUDE above block casting or deck surface. PIN PUNCHING may be used to tighten a loose valve seat. No more than eight approx.evenly spaced pin punches per valve seat (see Figure701.13 for location and placement of pin punches). When re-facing valve seats it must be understood that if the tool for checking valve seat height enters valve seat, legality will be determined by that gauge.

*** The block in the picture would not come close to meeting spec..*****
 
I think Mac's picture is just an old flathead that had a intake seat that got loose and was put back in place and punched in hopes that it would till or blow another day. No signs that it was some ones kart racing engine.
 
Freezeman said:
I think Mac's picture is just an old flathead that had a intake seat that got loose and was put back in place and punched in hopes that it would till or blow another day. No signs that it was some ones kart racing engine.
Click to expand...
O ya, no this wasn't proof of a racing engine, it was asked on another site what was going on here. Racing or not I personally have never seen this and figured a few might know what's going on haha. So no, not necessarily a racing block.
 
I have a Limited that I faught with for weeks and my engine builder finally said he knew what the problem was. Took it home with him and done this and it ran great like it should. Then the next time I tried to race it a year later it started doing the same thing again. So it does work!
 
What it actually is called is staking the seat. Briggs has a repair manual and shows you how to do it. Dont know why it would be a problem as long as the seat was not lowered or raised. Just a good way to keep a engine alive that other wise would be junk.
 
OlsonKarter said:
What it actually is called is staking the seat. Briggs has a repair manual and shows you how to do it. Dont know why it would be a problem as long as the seat was not lowered or raised. Just a good way to keep a engine alive that other wise would be junk.
Click to expand...
sinking valves is allowed
 
That was something done basically in mower shops and the earlier days of flatheads, after CV products and EZ bore started making over size seats you simply put an oversize seat in and used the EZ bore tool to stake it in. The biggest problem I found with pin punching was that it worked well when the engine was cold but if you pressure tested it with the block temp at 400 deg it would leak and sometimes the seat would spin and tear up the pocket.
 
The EZ Bore seat installing tool is the way to go. It hammers a small roll over the edge of the seat and can even help the airflow - especially over pin punching. Limit is 8 pin punches. You'll need to re-cut the seat AFTER pin punching as you will always move the seat slightly with the first two punch marks.
FWIW, you should use a slightly larger od seat (also offered by EZ Bore) rather than stock seats after a seat has come loose or is leaking.


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
www.youtube.com
34 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
You must log in or register to reply here.
Back
Top