Alloy vs Steel uprights on S1

[Shug]

I don't know how much truth there is in this, but people say (and I am aware that there is a lot of myth and folklore) that a block that's been used is a better starting point, provided there is no damage to it. The rationale is that you're going to get the liner heights set before you build the engine, and that a new block will deform over some period of heat cycling/load until it settles into its "final" shape. So best to deck a block that's settled rather than a brand new one. Now is this true? I don't know for sure because I don't know enough about what normal temperature range heat cycling does to the alloy used in the block.

That said there are clear examples of people using brand new blocks without problems so clearly not guaranteed to fail either.

Cheers,
Robin

Not directly related, but in the 80s, BMW used a road car block as the basis for their 1500bhp F1 engines. These blocks were taken out of cars with at least 100,000 miles on them, then left out the back of the factory (story has it, with the workforce taking leaks on them) to 'season' them before re-machining and building up. The argument was just that - the metal had done all it's settling and was now 100% stable. All the internal stresses were gone.

[BiggestNizzy]

I don't know how much truth there is in this, but people say (and I am aware that there is a lot of myth and folklore) that a block that's been used is a better starting point, provided there is no damage to it. The rationale is that you're going to get the liner heights set before you build the engine, and that a new block will deform over some period of heat cycling/load until it settles into its "final" shape. So best to deck a block that's settled rather than a brand new one. Now is this true? I don't know for sure because I don't know enough about what normal temperature range heat cycling does to the alloy used in the block.

That said there are clear examples of people using brand new blocks without problems so clearly not guaranteed to fail either.

Cheers,
Robin

Not directly related, but in the 80s, BMW used a road car block as the basis for their 1500bhp F1 engines. These blocks were taken out of cars with at least 100,000 miles on them, then left out the back of the factory (story has it, with the workforce taking leaks on them) to 'season' them before re-machining and building up. The argument was just that - the metal had done all it's settling and was now 100% stable. All the internal stresses were gone.

When maching long pieces of crap steel we still rough them down before throwing them in a puddle out back for a week to let them do what they want.

[robin]

left out the back of the factory (story has it, with the workforce taking leaks on them) to 'season' them before re-machining and building up. The argument was just that - the metal had done all it's settling and was now 100% stable. All the internal stresses were gone.

When maching long pieces of crap steel we still rough them down before throwing them in a puddle out back for a week to let them do what they want.

Good, that's pretty much how I've treated the block I had in mind for Campbell

[campbell]

LOL you lot!

Sanjoy, I'll pass on the Maser monster.

Shug, you are an anorak.

Nizzy, you are our resident metal head so thanks for the tech guidance.

Robin, I simply don't believe you.

Would like Stu Pollock's opinion on the matter too if poss...?

I am starting to think a "Project K Rebuild" thread is in order tho. Hijacked this one quite enough - sorree!

[woody]

New thread time: Campbell, my new super K.


Full circle.

[campbell]

Rebuild thoughts now relocating to here:

http://www.scottishelises.com/phpbb/vie ... =5&t=36072

[KingK_series]

Not that I ever sell cars I would expect to leave it as is (i.e. rebuild with your block if required) is probably best value in long run. The sort of person that will care about the engine being 100% standard will also want a standard exhaust, standard interior .... they'll probably even want standard red konis

So the next category after "original spec" is "well maintained and sensible" I think.

Cheers,
Robin

No that's not right - see my comments about Lanzante's advice

they after all look after cars that are worth millions each! so their view is probably pretty well authoritative

[KingK_series]

To compare standard S1 alloy uprights with standard S1 steel uprights the bolt is in single shear on both; so unless you were going to fit the uprated toe link kit, the toe link arrangement is the same on both and both will fail/not fail much the same as one another. If you have alloy hubs and you're on track with sticky tyres then you have the option of fitting the uprated toe link kit which is an advantage, I agree.


Cheers,
Robin

Good that was my point! but also - the hubs are much stiffer because of their width compared to the narrow steel design, S1 or S2 - see F1 or Le Mans upright design to see what I mean.

[KingK_series]

I don't know much about metallurgy but I would expect the alloy to expand more than steel when hot. So whilst you can use this to your advantage when removing the old bearing, does it not also reduce the friction force on the bearing outer when the hub is properly hot (e.g. when on track with sticky tyres)? In this case the bearing might then shift or spin marginally in the hub and gradually fret away at the bearing tunnel in the hub. As soon as the bearing outer can move, the bearing will fail eventually and you won't be able to fix by replacing bearing. So whilst you can blame the loose bearings on people removing them without heat, you can also blame it on the hubs getting hot, I think.

I've seen this in action at Charade in France (an extreme example as it was a hot day, on an abrasive track, with people using sticky tyres). At the close of play I went around and wobbled the wheels on a load of SE S1 sheds (all old and thus alloy hubs). Each and every one had what appeared to be a loose bearing on several wheels. The next morning they were all tight. I can only assume this is down to the expansion of the hub, as the bearing itself will get tighter when hot, not looser, I think.


Cheers,
Robin

Yes.......

but the solution is not to think - oh we must use steel uprights even though they flop about because they lack the stiffness of the Ally's because the co of expansion in upright and bearing is the same

- the solution is to duct and cool the hubs/discs

most race S1 Exiges I have put engines in, all actually, have ducted rear hubs, with their steel uprights - otherwise the bearing life is ridiculously short

[KingK_series]

[quote="robin"
Regardless of whether you have alloy or steel you need to check the flanges when you replace the bearing - I've seen a couple of tapered ones, including on a car that is rarely tracked. Again, not knowing much about metallurgy I cannot say that the EP "harder steel" items are better than OEM or not, but given the OEM ones fail, I would fit the harder ones.

So the alloy hubs might be better if (a) you track it a lot (b) probably on sticky tyres (c) you fit the uprated toe link kit (d) you don't mind replacing the hub when the bearing tunnel is damaged. In all other cases the steel hubs are as good and have the advantage of being much harder to damage by hamfisted bearing swappery.

Cheers,
Robin[/quote]

- In my experience the flange pin gets tapered/fretted because the split bearings are not properly closed up - ie they have been fitted with sockets haphazardly rather than with accurately machined tooling

seen it loads of times


same mistake knackers ally uprights too -

[KingK_series]

I don't know how much truth there is in this, but people say (and I am aware that there is a lot of myth and folklore) that a block that's been used is a better starting point, provided there is no damage to it. The rationale is that you're going to get the liner heights set before you build the engine, and that a new block will deform over some period of heat cycling/load until it settles into its "final" shape. So best to deck a block that's settled rather than a brand new one. Now is this true? I don't know for sure because I don't know enough about what normal temperature range heat cycling does to the alloy used in the block.

That said there are clear examples of people using brand new blocks without problems so clearly not guaranteed to fail either.

Cheers,
Robin

It is.... if the block is a heat treated ally - ie LM25


I believed the story about BMW 1.5L F1 engines too, even quoted it

- I was wrong, it's bull

I have met one of the engineers who built them, he said that they all heard this story and p888ed themselves laughing

- they also for a laugh got a scrapper engine and built it up to full F1 spec to test - it blew up spectacularly on the dyno


those BMWs were simple cast iron - not heat treated ally.

[robin]

So we are better with a used but not damaged block rather than a brand new casting?

My point about car values was only that given his car is not "original spec" which attracts a lot of value from the garage jewellers and anoraks, a well maintained and sensible spec car is likely to be next in the value (money back vs money spent) department. That's not to say that a super-duper tuned job with all the other possible improvements you can make might not be worth more, but it will also have cost you more.

Cheers,
Robin

[Shug]

I don't know how much truth there is in this, but people say (and I am aware that there is a lot of myth and folklore) that a block that's been used is a better starting point, provided there is no damage to it. The rationale is that you're going to get the liner heights set before you build the engine, and that a new block will deform over some period of heat cycling/load until it settles into its "final" shape. So best to deck a block that's settled rather than a brand new one. Now is this true? I don't know for sure because I don't know enough about what normal temperature range heat cycling does to the alloy used in the block.

That said there are clear examples of people using brand new blocks without problems so clearly not guaranteed to fail either.

Cheers,
Robin

It is.... if the block is a heat treated ally - ie LM25


I believed the story about BMW 1.5L F1 engines too, even quoted it

- I was wrong, it's bull

I have met one of the engineers who built them, he said that they all heard this story and p888ed themselves laughing

- they also for a laugh got a scrapper engine and built it up to full F1 spec to test - it blew up spectacularly on the dyno


those BMWs were simple cast iron - not heat treated ally.

That's a shame... Have read that story dozens of times over the past 20 years in various historic racing mags, written by many respected journalists.

Would have thought one of them would have thought to check over the years, if as you say, a simple conversation with an engineer of the period would have debunked it...

I suppose a good apocryphal story will always win out.

[KingK_series]

I don't know how much truth there is in this, but people say (and I am aware that there is a lot of myth and folklore) that a block that's been used is a better starting point, provided there is no damage to it. The rationale is that you're going to get the liner heights set before you build the engine, and that a new block will deform over some period of heat cycling/load until it settles into its "final" shape. So best to deck a block that's settled rather than a brand new one. Now is this true? I don't know for sure because I don't know enough about what normal temperature range heat cycling does to the alloy used in the block.

That said there are clear examples of people using brand new blocks without problems so clearly not guaranteed to fail either.

Cheers,
Robin

It is.... if the block is a heat treated ally - ie LM25


I believed the story about BMW 1.5L F1 engines too, even quoted it

- I was wrong, it's bull

I have met one of the engineers who built them, he said that they all heard this story and p888ed themselves laughing

- they also for a laugh got a scrapper engine and built it up to full F1 spec to test - it blew up spectacularly on the dyno


those BMWs were simple cast iron - not heat treated ally.

That's a shame... Have read that story dozens of times over the past 20 years in various historic racing mags, written by many respected journalists.

Would have thought one of them would have thought to check over the years, if as you say, a simple conversation with an engineer of the period would have debunked it...

I suppose a good apocryphal story will always win out.

sorry...

[KingK_series]

So we are better with a used but not damaged block rather than a brand new casting?

My point about car values was only that given his car is not "original spec" which attracts a lot of value from the garage jewellers and anoraks, a well maintained and sensible spec car is likely to be next in the value (money back vs money spent) department. That's not to say that a super-duper tuned job with all the other possible improvements you can make might not be worth more, but it will also have cost you more.

Cheers,
Robin

S1s as opposed to S2s or any Toyota cars are now collectors cars.... like jaguar E types, or MClaren F1s,

the most valuable are the small production runs

ie Exige S1
340R
190 Sport
160
135 Sport


the engine is the important thing because it's different from dampers and seats and steering wheels..... why because it is the only part that has its own bespoke serial number to tie it to a chassis number

and if you go buy a Ford GT40, or a Ferrari GTO the first thing any vendor will want to tell you is that it has the original engine.

its big

that is why s1 honda conversions used to sell for 16k
but now even noice ones are 13/14k on Pistonheads and they will keep on going down according to those that know..