Re: Digest Number 822

Benson · Post by **Benson** » Thu Apr 25, 2002 1:22 pm

Hi All, Not exactly a question on plug wires but plugs(sparking). Got any tips on what type of plugs I should be using now I,m unleaded and got TF valves and! a slightly higher comp. ratio? Also what jet size and needle for 1 1/2 SU carbs? The Suns getting hotter in N. Yorks. Regards, Ron Benson TB

joecurto@aol.com · Post by **joecurto@aol.com** » Thu Apr 25, 2002 3:01 pm

Ron I run GJ needles and stock .090 jet for TF type spec, LS1 (TD MK2) is very rich. Start out with GJ and go from there. Joe curto [Non-text portions of this message have been removed]

Skip Kelsey · Post by **Skip Kelsey** » Fri Apr 26, 2002 8:34 am

Ron: I agree with Joe Curto. If you have hotted up your HP with high compression, cam, bigger bore, and maybe an extractor exhaust, then I would recommend EL needles with the 1 1/2 SUs. This works quite well. On my own car with the above, I will burn valves with the GJ needles. The engine is just too efficient for the stock TF needles. Skip Kelsey.........................................................At 09:21 PM 4/25/02 +0100, Benson wrote:

>Also what jet size and needle for 1 1/2 SU carbs?

Benson · Post by **Benson** » Sat Apr 27, 2002 9:35 am

----- Original Message ----- From: "John T. Seim" kingseim@earthlink.net> To: "Benson" Carole_Ron@benson30.fsnet.co.uk> Sent: Friday, April 26, 2002 5:43 PM Subject: Re: [mg-tabc] Digest Number 822 > 1/2" reach threaded hole in head, or 3/4" threaded hole? > Hi John, I thought all XPAG heads used 1/2" reach plugs, the one that I have modified is not the original head and I am not sure what it is off. Is it just a case of measuring? Regards, Ron Benson TB

Chip Old · Post by **Chip Old** » Sat Apr 27, 2002 10:27 am

On Sat, 27 Apr 2002, Benson wrote:

> I thought all XPAG heads used 1/2" reach plugs, the one that I have > modified is not the original head and I am not sure what it is off. Is > it just a case of measuring?

XPAG heads use either 1/2" or 3/4" thread length plugs, depending on age. The heads used on the TB, TC, and early TD use 1/2". The heads used on the late TD, TF, and TF 1500 (XPEG) use 3/4". There is no need to measure, as there are several other indicators. If the head is on the engine, look for a casting number on the top surface of the head, right front corner. If it is "22952", it's an early head. If the number is something else (I forget what) or nonexistant, it's a late head. If the head is off the engine you can tell by looking at the small water passage holes that carry coolant between the block and the head. If they are oblong (some say banana-shaped) it's an early head. If they are round it's a late head. The early head is sometimes referred to as a "banana head" and the late head as a "round head" due to the shape of the water holes. XPAG engine blocks also have either oblong or round water holes, again following the "TB through early TD" and "late TD and TF" pattern. It's okay to use a late head on an early engine or vice versa, as long as you use the appropriate head gasket. If head and block both have oblong water holes, use a gasket with oblong water holes. If head and block both have round holes, use a gasket with round holes. If you use a head of one type on a block of the other type, use a gasket with oblong water holes. -- Chip Old 1948 M.G. TC TC6710 XPAG7430 NEMGTR #2271 Cub Hill, Maryland 1962 Triumph TR4 CT3154LO CT3479E fold@bcpl.net

Skip Kelsey · Post by **Skip Kelsey** » Sat Apr 27, 2002 11:33 am

Chip: I have been running a "bannana" block, bored .100, and a "round" head for the past 40 years, using a TF-1500 head gasket. Due to the overbore, and not wanting the gasket to overhang the cyls. It has never given me any trouble. The current rebuild,now has 55,000 miles on it, and is heading for Durango,Co. in June to the GoF. SKip Kelsey.................................................. At 01:27 PM 4/27/02 -0400, Chip Old wrote:

>holes, use a gasket with oblong water holes. If head and block both have >round holes, use a gasket with round holes. If you use a head of one type >on a block of the other type, use a gasket with oblong water holes

Chip Old · Post by **Chip Old** » Sat Apr 27, 2002 1:17 pm

On Sat, 27 Apr 2002, Skip Kelsey wrote to Chip Old and MG-TABC:

> Chip: > > I have been running a "bannana" block, bored .100, and a "round" head > for the past 40 years, using a TF-1500 head gasket. Due to the overbore, > and not wanting the gasket to overhang the cyls. It has never given me > any trouble. The current rebuild,now has 55,000 miles on it, and is > heading for Durango,Co. in June to the GoF.

Yes, if the amount of overbore requires an XPEG head gasket, then you don't have much choice unless you get a gasket custom made. The problem I used to run into with a round-hole gasket and a banana block or head was due to the way one copper layer is (or at least used to be) wrapped back over around the edges of the holes. If the edges weren't crimped together between head and block, coolant would gradually seep into the core of the gasket. Eventually the core would disintegrate. Maybe I just bought cheap gaskets.

-- Chip Old 1948 M.G. TC TC6710 XPAG7430 NEMGTR #2271 Cub Hill, Maryland 1962 Triumph TR4 CT3154LO CT3479E fold@bcpl.net

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