116 replies to this topic

[u1 71]

australian muscle cars sold a white l34 recently wth hz engine no.ending with the letter r.

[u1 71]

3100x and 2600s engine no.stamps used were of a larger diameter then the ones used to stamp the ck and jp blocks.

[yel327]

so is there also an elusive 2600n ?

Yes. There will be replacement engines for just about every original engine. I can't guarantee you one was made, but it stands to reason there would be heaps.

[u1 71]

the numbered stamps used to stamp the blocks were put into a jig then put into a press to stamp the blocks.thets why all the numbers were evenly spread apart and also lightly stamped.

hi trash the bucket,your original jp block would be at russelvale tip under 40 odd years of rubbish.

[frash da bucket]

Hi Peter,

Block went to berrima tip,

And the old engine number was smashed of the side with a sledge hammer,

Thats what my original owner told me,he did it,in the metal section,

the old block could have turned into something else these days.

Cheers John.

[S pack]

As above for NP.

The Nasco replacement engine number sequence you are talking about started at HQ engine release. This was around May 1971. The first engine Nx1001 could have been anything that was used in HQ, LC or HG at the time but one thing it COULDN'T have been was NK as these were not in use as CK engines until later in 1971. Between HQ engine release and NK engines the replacement XU-1 engine would have been 3100N prefixed.

Hello again,
So if I have this right then you are saying that the Holden Service letter advising that NK engines were available fron the release of the HQ in July 1971, is wrong?

Mike

You must have a different version of Dealer Service Letter 141, dated 19th August 1971. The one I have makes no mention about availability of NK prefix engine blocks, only the introduction of the new CK prefix.

[meanmachine72]

:badabing:heheheheh

Edited by meanmachine72, 01 October 2011 - 07:18 PM.

[S pack]

The only other thing that springs to mind is if the R at the end of these engines has some "race" significance then it would be on the Nasco replacement engines built for the 150 x 1973 "Bathurst cars". These engines were different to all other engines not listed on that bulletin and the purpose of that letter was to let servicing dealers know that they are different. So possibly an R was used to signify these engines as different from a spare parts perspective? And that is why it is away from the engine number?

With 20/20 hindsight logic tells me it should have been obvious.....

^^^ I've been thinking this sounds quite plausible.
Looking at the pic that was posted of Engine No. NP7100, it appears the 'R' was positioned well away from the engine number for a reason.
I seriously doubt that the 'R' was ever intended to be read as part of the engine number, otherwise it surely would have been stamped at the end of the number.

GMH Dealer Service Letter dated October, 1973 page 366 starts off to say - quote: "Revised Torana XU-1high performance engines were introduced for August 1973 production" unquote.

Maybe the R = Revised. Some form of distinct identifying mark may have been needed as Nasco had to supply two different replacement 202 XU-1 engines at the same time from August 1973 onwards.

Such a marking would have also helped ANDCO differentiate between the std NP XU-1 block and the High Performance NP XU-1block.

Edited by S pack, 02 October 2011 - 01:02 AM.

[yel327]

That is what I reckon too. WIth most other engines a different prefix was used if the engine was more than minimally different. The LJ XU-1 is probably the only exception (that I can think of anyway).

[TheKing]

Just to add to the mystery, my NP7100R has the cutouts in the block for the larger valves as a replacement for a Bathurst engine. I know of another NP7###R that does not have these cutouts.

Cheers Jeff

[WhiteA9XS]

mike73 , its either you,ve done your homework or talked to the right person .

NP blocks with the letter R were special cast blocks by the commonwealth aircraft factory with a higher nickel content .

not many were cast , possibly 50 and were for racing .

this information came from a reliable source who built these engines for the race teams back in the 70,s.

[yel327]

I don't doubt CAC (majority owned by GMH) cast XU-1 blocks, but I was lead to believe they did a lot more than 50 and they weren't just NP engines. However it is possible that the R on an NP engine signifies that the block was one of those specials, it is as good an idea as any. The cast date on the NP7100 engine would probably be much earlier than the engine number indicates, and if this is true the R was probably put there when the block was machined. The NP7100 was obviously stamped later as this is significantly later in the Nasco sequence than when XU-1's were new. ALl conjecture though until someone finds some facts.

[TheKing]

G'day, the cast date on NP7100R is August 74.

Cheers Jeff

[yel327]

That bothers me with that theory then, as I doubt any more specials would be cast at that time.

[WhiteA9XS]

G'day, the cast date on NP7100R is August 74.

Cheers Jeff

jeff , can you confirm if the appearance is different with the NP "R" block standing next to ordinary block or by wire brushing both to see if its shines more ?
allthough i,m no metal expert but just a long shot and assuming its out of your car .... interesting as one would think 202 race blocks would be a thing of the past in aug 74 !!

[TheKing]

Engine is a spare and in storage shed, will check it next couple of days.

Cheers Jeff

[frash da bucket]

Hi Jeff,

My NP engine no is higher than yours,mine with a 7 H 3 cast.

Cheers John.

[yel327]

^^That makes a lot more logical sense. It is what I'd expect for a late numbered NP block to have as a cast date.

[TheKing]

G'day John, mate my engine number stamping is the same as yours but block has the cutouts in the top for the larger valves so a replacement for a 73 Bathurst engine. I cannot make sense of the number sequencing, when I'm finished building the wife's VK will full NP down and look for those internal markings.

G'day WhiteA9XS, I'm no metal expert either but after wire brushing number it looks original and same as a May 74 NL block I have. XU1's were still racing in 1974 ATCC and Bathurst Ferodo 1000 so 73 Bathurst Torana's would still have required spare blocks for warranty and race replacements.

Cheers Jeff

[enderwigginau]

mike73 , its either you,ve done your homework or talked to the right person .

NP blocks with the letter R were special cast blocks by the commonwealth aircraft factory with a higher nickel content .

not many were cast , possibly 50 and were for racing .

this information came from a reliable source who built these engines for the race teams back in the 70,s.

That is false. Confirmed by more than one person involved at the time including the one signing the requisitions.

High nickel cast iron was used up to and including HP cast blocks. It continued after these large capacity blocks were changed to show capacity instead. Not sure when the change to low nickel-content iron occurred, but during early 308 block production. Possibly coincided with the change to cast cranks, as steel cranks may have had adverse effects on the softer cast iron.....

Grant..