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3.9 L V8 : High Compression vs Low Compression

Tech Talk for Rover owners.

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Jay
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3.9 L V8 : High Compression vs Low Compression

Post by Jay »

Anyone know the suffix on the engines of a 3.9 L High Compression versus a 3.9 L Low Compression.

Thanks,


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Post by RangingRover »

I didn't know there were high comp 3.9s? The comp ratio is generally stamped right above the engine number on the block anyway...
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Post by Daisy »

Readin thru my owners manual in my previous car (94 LR disco) it stated a high comp and a low comp engines were available.

When my bro in law comes home i'll have a look at his book..

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Post by RaginRover »

I didn't think any came to Australia

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Post by peter r »

zzzzz
Last edited by peter r on Wed Dec 27, 2006 11:46 pm, edited 1 time in total.
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Post by Jay »

RangingRover wrote:I didn't know there were high comp 3.9s? The comp ratio is generally stamped right above the engine number on the block anyway...
The High Compression comes with 9.35 stamped on the engine.

The Low Compression comes with 8.13 stamped on the engine.

Both stand for compression ratio 9.35:1 versus 8.13:1

Both engines exist in the Lebanese market. The country being very hilly the high compression runs much better going uphills.
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Post by RangingRover »

We have high comp 3.5s, 4.0s and 4.6s here, but I've never seen a factory highcomp 3.9 (well, not that I've noticed!)... I think, as someone else said previously, they may not have reached Australia for some reason... Which, considering we got highcomp versions of every other motor, is somewhat odd. But there you go, car manufacturers often seem to make odd decisions about what to release in Australia.

Does anyone have a definitive answer as to whether high comp 3.9s were sold in Aust, just to satisfy my personal curiousity?
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Post by Reddo »

Me thinks the crap (low Cetane/Octane) Aussie fuels would have prevented it......I'm guessing but this is the reason we don't/have not see/n high compression motors from Europe in the past - and motors like the Astra/Vectra have on-going issues
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Post by LRHybrid100 »

Low Comp 3.9s are 37D00001+ for manual and 38D00001+ for auto

High Comp 3.9s are 35D00001+ for manual and 35D00001+ for auto

Only diff is the pistons

HTH

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Post by LRHybrid100 »

Aus only got the shitty LC - as the fuel was crap

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