XPAG Heads

[Steve S]

Hi all, seeking a bit of advice. 1. Is there any advantage or disadvantage of a long reach head versus short reach? 2. Has anyone successfully repaired a cracked XPAG head? I have a head here with two cracked exhaust seats. One of the cracks extends to the base of the chamber wall. It's an uncut head so I hate to scrap it. - Steve Simmons, TC8975

[Steve S]

Yes, heads with 1/2" versus 3/4" reach spark plugs. - Steve On 1/28/2018 2:50 PM, Madhu Paroor wrote:

Hi Steve, Sorry for my ignorance about the Question 1, Are you referring to the spark plug short reach and Long reach ? madhu 2018-01-27 19:57 GMT+01:00 Steve S mail@mgnuts.com [mg-tabc] mg-tabc-noreply@yahoogroups.com>: Hi all, seeking a bit of advice. 1. Is there any advantage or disadvantage of a long reach head versus short reach? 2. Has anyone successfully repaired a cracked XPAG head? I have a head here with two cracked exhaust seats. One of the cracks extends to the base of the chamber wall. It's an uncut head so I hate to scrap it. - Steve Simmons, TC8975

[Bob Grunau]

Agreed, TB/TC/early TD and YA/YT heads are reach spark plugs , banana water holes and 22952 cast into right front top surface.

Later round hole heads are reach spark plugs and 168422 cast into right front top.

 

I have never had a cracked exhaust seat head repaired. I think better to find another head, unless a rare head.

Bob, Canada,

 

 

 

[b]From:[/b] mg-tabc@yahoogroups.com [mailto:mg-tabc@yahoogroups.com] [b]On Behalf Of [/b]Steve S mail@mgnuts.com [mg-tabc] [b]Sent:[/b] Sunday, January 28, 2018 5:57 PM [b]Cc:[/b] MG tabcgroups [b]Subject:[/b] Re: [mg-tabc] XPAG Heads

 

 

Yes, heads with 1/2" versus 3/4" reach spark plugs. - Steve  

On 1/28/2018 2:50 PM, Madhu Paroor wrote:

Hi Steve,

Sorry for my ignorance about the Question 1,

Are you referring to the spark plug short reach and Long reach ?

madhu

 

2018-01-27 19:57 GMT+01:00 Steve S mail@mgnuts.com [mg-tabc] mg-tabc-noreply@yahoogroups.com>:

 

Hi all, seeking a bit of advice. 1. Is there any advantage or disadvantage of a long reach head versus short reach? 2. Has anyone successfully repaired a cracked XPAG head?  I have a head here with two cracked exhaust seats.  One of the cracks extends to the base of the chamber wall.  It's an uncut head so I hate to scrap it. - Steve Simmons, TC8975

 

 

[Madhu Paroor]

Hi Steve, Sorry for my ignorance about the Question 1, Are you referring to the spark plug short reach and Long reach ? madhu 2018-01-27 19:57 GMT+01:00 Steve S mail@mgnuts.com [mg-tabc] mg-tabc-noreply@yahoogroups.com>:

[u][/u] Hi all, seeking a bit of advice. 1. Is there any advantage or disadvantage of a long reach head versus short reach? 2. Has anyone successfully repaired a cracked XPAG head? I have a head here with two cracked exhaust seats. One of the cracks extends to the base of the chamber wall. It's an uncut head so I hate to scrap it. - Steve Simmons, TC8975

[Madhu Paroor]

Hi steve, The half inch threads came from the Flatt cylinder head Era. OHV cylinder head of early XPAG had half inch Plugs, but then the modified to accommodate 3/4 inch plugs with more thread grip and thermal qualities. With new extended tip they tried to get the spark moved towards the center of the Cylinder to influence the engine effiency. Imagine the design engineers never had speed camera and sensors, on those days. The BMW 328 cylinder head was very complicated and had lot of problems and cracked very often. The engine was short. The gap between the cylinder was very limited. The spark plug had a bigger diameter than today was a week point weakeing the material strength. There are many other factors to address. But now using new thin spark plug they are manufacturing new cylinder heads for BMW and price tag is above 12.000-15.000 . They were able get more metal strength in that short gap of small six cylinder engine. Compared to BMW cylinder head our XPAG is very robust and simple in construction. We can go on discussing about it. This is only my simple way of thinking. madhu 2018-01-28 23:56 GMT+01:00 Steve S mail@mgnuts.com [mg-tabc] mg-tabc-noreply@yahoogroups.com>:

[u][/u] Yes, heads with 1/2" versus 3/4" reach spark plugs. - Steve On 1/28/2018 2:50 PM, Madhu Paroor wrote: Hi Steve, Sorry for my ignorance about the Question 1, Are you referring to the spark plug short reach and Long reach ? madhu 2018-01-27 19:57 GMT+01:00 Steve S mail@mgnuts.com [mg-tabc] mg-tabc-noreply@yahoogroups.com>: Hi all, seeking a bit of advice. 1. Is there any advantage or disadvantage of a long reach head versus short reach? 2. Has anyone successfully repaired a cracked XPAG head? I have a head here with two cracked exhaust seats. One of the cracks extends to the base of the chamber wall. It's an uncut head so I hate to scrap it. - Steve Simmons, TC8975

[Bill Hyatt]

Steve/Madhu,

It is my recollection that evolution of spark plug to was due to change in cooling passage design in later engines with aim for improved cooling.

 

Bill

TC 4926

Odessa, Fl

 

[b]From:[/b] mg-tabc@yahoogroups.com [mailto:mg-tabc@yahoogroups.com] [b]On Behalf Of [/b]Madhu Paroor madhuparoor@gmail.com [mg-tabc] [b]Sent:[/b] Sunday, January 28, 2018 5:51 PM [b]To:[/b] Steve S [b]Cc:[/b] MG tabcgroups [b]Subject:[/b] Re: [mg-tabc] XPAG Heads

 

 

Hi Steve,

Sorry for my ignorance about the Question 1,

Are you referring to the spark plug short reach and Long reach ?

madhu

 

2018-01-27 19:57 GMT+01:00 Steve S mail@mgnuts.com [mg-tabc] mg-tabc-noreply@yahoogroups.com>:

 

Hi all, seeking a bit of advice. 1. Is there any advantage or disadvantage of a long reach head versus short reach? 2. Has anyone successfully repaired a cracked XPAG head?  I have a head here with two cracked exhaust seats.  One of the cracks extends to the base of the chamber wall.  It's an uncut head so I hate to scrap it. - Steve Simmons, TC8975