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XPAG Heads
Posted: Sat Jan 27, 2018 10:57 am
by 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
Re: XPAG Heads
Posted: Sun Jan 28, 2018 2:58 pm
by 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
Re: XPAG Heads
Posted: Tue Jan 30, 2018 8:51 pm
by 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
Re: XPAG Heads
Posted: Wed Jan 31, 2018 2:38 am
by 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
Re: XPAG Heads
Posted: Wed Jan 31, 2018 12:10 pm
by 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
Re: XPAG Heads
Posted: Wed Jan 31, 2018 12:39 pm
by 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 4926Odessa, 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