Thread: Want to get this lot on the front rather than the rear!

Sounds like a happening thing! Good luck!

Turns out the cheap short engine I bought has a mushy (soft) block. Hardness readings below 80 means they won't touch it. Does that sound reasonable? Must have been overheated once too many times. The story I was told was that one piston had seized after the p38 had continued to run on its side. Hence the damaged piston and liner. Shame about the block.

Managed to source a new block for reasonable money. Just hoping the 2nd hand crankshaft & conrods check out ok. The crack test on the crankshaft was ok.

Further developments. Orger have managed to sort out 8 good pistons from ten HC pistons I gave them - they were initially quibbling. But they can't assemble 8 gudgeon pins from the 18 I gave them. Need to get 8 new pins. Any suggestions? Don't want to have to buy new pistons.

I've had to buy +10" crankshaft bearings. Thought the crankshaft was still in tolerance, but they want to grind it. I'd originally given them standard bearings.

Also had to get extra 2nd hand conrod as one was bent.

Serves me right for trying to do an engine rebuild on the cheap!

What a bloody palaver.

After the 2nd hand block failing so miserably on the hardness test, I had high hopes for the new block I'd sourced and supplied to Orger. They've found (legitimately) that it needs new bushings/sleeves for 2 of the camshaft bearings - due to poor LR casting. The casting is rough and oversized and won't hold the bearing in its current state.

There were three crankshaft oil galleries that needed drilling out - scary.

Also, it seems that the crankshaft caps have been swapped over at some point - so there is a step where the cap meets the block - meaning the crankshaft tunnel needs off-centre line boring. Jeese.

Of course, the orginal objective was to sleeve the block.

Does anybody want a soft block - they make nice coffee tables!!

Moral of the story - buy a ready made, sleeved long engine. Cash flow and cheapness on my part prevent me from doing this.

The cylinder heads are to be polished (0.002" to 0.003") again due to scratches. The skim had been done in the UK (cheap heads once again) - so can't blame Headworks for a job they didn't do. Headworks built up the heads and ported them - I'm hoping no further fault can be found with them.

And the latest: the 2nd hand high comp pistons I ordered out of the states are actually for a 4.0 - when I'd specifically ordered 4.6. The dangers of dealing with breakers in remote far off places. I've been back in touch with them to see what they say (for $175 landed - they were a bargin - or so I thought).

Using the 4.0 pistons would give me a compression ratio of 12.8 - a little high me thinks. The calcs show that a standard deck height of 0.030" with the 4.6litre HC pistons will produce 9.5:1 (any comments about quench/deck height?). Could the deck height be reduced for higher comp? Should it? Standard out of the factory was 9.38:1 I believe. The head skim is negated somewhat by the composite gasket.

Still waiting on the new piston/gudgeon pins. I've had to order these from Summit racing - do you realise how hard it is to get these things without the pistons. The pins that came with the 2nd hand pistons weren't considered worthy.

Now I'm in a bit of a quandry. Do I bite the bullet and get a new set of pistons (with pins and rings included). GBP299 incl VAT from V8 Tuner. Plus P&P of course. The price on Island4x4 is GBP47 each excl VAT for OEM quality or about half that for the Britpart version.

Can anybody offer any suggestions or alternatives?

I'd then have a set of 4.0litre HC pistons, with new pins and new rings to offload.

The bill is building. I'm getting nervous.

Calculations reveal the following:

4.6 litre LC pistons have recess volume of 32.2c.c. With a 0.045" gasket and zero deck height, the compression is 9.3:1. A compression ratio of 9.5:1 can be achieved with a tdc piston protrusion of 0.005".

4.6 litre HC pistons have a recess volume of 22c.c. Producing 10:1 compression at 0.030" deck height. This deck height is per factory, but I've been told by a reliable source, it should be less - approaching zero to 0.05". This produces better torque.

So it looks like a recess volume of 27 c.c. is what would be ideal? To get the 10:1 ratio (LPG is one of the goals of this). Custom pistons are $1250!! Ouch.

Any comments/thoughts/observations. I'm no expert (as you can probably tell from all these screw ups) - so would appreciate advice.


I'm leaning towards the LC piston (which I can readily get of course) with the reduced deck height.

Thats still a cheap set of pistons. Come back to me when you get pay 16,000 for a set and you've ordered 3 sets.

Not sure what you mean? Why would a set of pistons cost 16,000 and why would need 3x sets?

Dragster or very toey engine with mad forged pistons by the sounds of it...

Or a Cat 793 dumpy...