heres a chrysler nut showing his ignorance,
but what is the diff between the jp and the hp motors, etc
also, what were the different specs between gtr, gtr xu1. in both lc and lj?
just curious as to what work had been done to the donk, was it just cam and compression or was there more to it?
righto, heres my stupid question
Started by
_knighty_
, Apr 03 2006 11:12 AM
7 replies to this topic
#2
Dr Terry
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Posted 03 April 2006 - 12:46 PM
Hi knighty.
That's a lot of questions in one post, but I'll see if I can answer them.
Firstly JP is the prefix for the stamped engine number for the 202 in an LJ GTR XU-1. It is stamped on the engine mounting lug on the RH side the block near the distributor.
The HP is only a casting identification, it was used on all EH 179s up to Oct 64. If you do a search you will find numerous posts on the HP block myth. There is nothing special about the HP block, it is no different to any other 179 motor. Many people think that they are a special casting with a special 'forged' crank. Fact is, all Holden engines of all sizes up to April 67 have forged cranks.
The LC GTR has a 161 'S' motor (late '71 have a 173 'S') that has similar mods to the 186 'S' motor that was used in the HK/HT/HG Monaro GTSs. The LC GTR XU-1 has a modified 186 motor with a 161 type head resulting in 10.0:1 compression, special cam, exhaust headers similar to the 'S' motors & 3 CD-150 Zenith-Stromberg side-draught carbies on a suitable manifold. They were built for the 1970 & 1971 Bathurst 500.
The LJ GTR has a stock standard 202, the only mod being the chrome-plated air cleaner with no snorkel. The '72 LJ GTR XU-1 has a modified 202 with similar mods to the LC XU-1, stronger con-rods & this time with 3 CD-175 Zenith-Strombergs. The Bathurst '73 version gained full tubular extractors & further mods. There is more detail, but this should give you an idea.
Hope this answers the query.
Dr Terry.
That's a lot of questions in one post, but I'll see if I can answer them.
Firstly JP is the prefix for the stamped engine number for the 202 in an LJ GTR XU-1. It is stamped on the engine mounting lug on the RH side the block near the distributor.
The HP is only a casting identification, it was used on all EH 179s up to Oct 64. If you do a search you will find numerous posts on the HP block myth. There is nothing special about the HP block, it is no different to any other 179 motor. Many people think that they are a special casting with a special 'forged' crank. Fact is, all Holden engines of all sizes up to April 67 have forged cranks.
The LC GTR has a 161 'S' motor (late '71 have a 173 'S') that has similar mods to the 186 'S' motor that was used in the HK/HT/HG Monaro GTSs. The LC GTR XU-1 has a modified 186 motor with a 161 type head resulting in 10.0:1 compression, special cam, exhaust headers similar to the 'S' motors & 3 CD-150 Zenith-Stromberg side-draught carbies on a suitable manifold. They were built for the 1970 & 1971 Bathurst 500.
The LJ GTR has a stock standard 202, the only mod being the chrome-plated air cleaner with no snorkel. The '72 LJ GTR XU-1 has a modified 202 with similar mods to the LC XU-1, stronger con-rods & this time with 3 CD-175 Zenith-Strombergs. The Bathurst '73 version gained full tubular extractors & further mods. There is more detail, but this should give you an idea.
Hope this answers the query.
Dr Terry.
#3
FastEHHolden
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Posted 03 April 2006 - 12:50 PM
A HP has a steel crank and was a 179 (essentially it was nothing special),
a JP is an engine number prefix. I will leave it to the owners of said engines to point out the details.
a JP is an engine number prefix. I will leave it to the owners of said engines to point out the details.
#4
_knighty_
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Posted 04 April 2006 - 09:34 AM
so what's the difference between the 161 head and the xu1 head??
#5
Dr Terry
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Posted 04 April 2006 - 10:07 AM
Hi knighty.
The XU1 head has bigger valves, better ports & valve springs to suit the cam.
Dr Terry.
The XU1 head has bigger valves, better ports & valve springs to suit the cam.
Dr Terry.
#6
_knighty_
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Posted 04 April 2006 - 01:37 PM
sorry for all the questions BUT
is it origionally based on the 161 head? if so, what valves are fitted? how much port work? any pics??
is it origionally based on the 161 head? if so, what valves are fitted? how much port work? any pics??
#7
_finer70_
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Posted 04 April 2006 - 05:25 PM
From talking to a guy who had worked at GM during the XU1 era, the port work was prudent fettling.
Now fettling is a term for the removal of knobs and dags from castings. It was then a matter of interpretation of just how far the fettling went. eg fettle till smooth and shiny. That would be almost to a polish.
Now fettling is a term for the removal of knobs and dags from castings. It was then a matter of interpretation of just how far the fettling went. eg fettle till smooth and shiny. That would be almost to a polish.
#8
red6
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Posted 04 April 2006 - 07:42 PM
early prefix eg 186a out of hd's also had the steel crank
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