Cracked Block info

[llenrub]

I am inclined to agree with you. Have you got their contact details?

I'd really appreciate it!!

[MR2Mania]

I am inclined to agree with you. Have you got their contact details?

I'd really appreciate it!!

Do you mean Fraser? If so, PM me and I'll PM you back his contact details, although be warned, he's more out of the country than he is in.

[llenrub]

Fraziers not back untill the 18/4. Do you think I should have PTS stop work on the rebuild untill he gets back?

[MR2Mania]

Fraziers not back untill the 18/4. Do you think I should have PTS stop work on the rebuild untill he gets back?

You mean "FRASER"?

Did he say that he could help? In which case, it's probably worth the wait just so that you can put your mind at rest.

[ENSMR2]

I spoke to Fensport a while back about this. They said if the cylinder wall has a thickness of 160 thou then we should be ok. Any thing less and it's a no no more or less.

What kind of results should we expect from an ultrasonic test? Or should I say what result will mean we are ok and what will mean we aren't? Just so I know what I'm looking for when I get it done.
Or is this (ultrasonic test) just a measure of the thickness. In which case I already know it should be 160 thou.

N

[MR2Mania]

I spoke to Fensport a while back about this. They said if the cylinder wall has a thickness of 160 thou then we should be ok. Any thing less and it's a no no more or less.

What kind of results should we expect from an ultrasonic test? Or should I say what result will mean we are ok and what will mean we aren't? Just so I know what I'm looking for when I get it done.
Or is this (ultrasonic test) just a measure of the thickness. In which case I already know it should be 160 thou.

N

Hi N,

Fensport should know better than most, so I'd trust their advice.

I'm not sure though if they mean it should be 160thou BEFORE or AFTER a rebore, as most people will be overboring slightly.

Must ask them next time I speak to them....

[ENSMR2]

Yes I'm not sure what they meant. It was a while ago I spoke to them.

Let me know whne you find out.

Also what about the ultrasonic test result I asked about. What should I be hoping for when I get it tested?

Cheers Dino,
HTH

N

[MR2Mania]

Also what about the ultrasonic test result I asked about. What should I be hoping for when I get it tested?

Ultrasonic testing is HOW you determine the thickness! Basically, think of "ultrasound" testing that they do in hospitals on pregnant women. This essentially forms a picture of the baby by bouncing ultrasonic waves through the lady's belly. The different distances in the belly take different times to reflect the ultrasonic waves back, and hence the machine works out all dimensions.

The same applies to ultrasonically testing the block. They'll pick the thinner point and check for the thickness.

[ENSMR2]

Cheers Dino.

I'll be keeping my fingers crossed then. Will save a bit of money if it's ok.

[llenrub]

160 thou is 160 thousanths of an inch is it?

[llenrub]

Talking of pregnancy, I phoned the hospital and told them, "my wife is expecting, expecting a new car, could I bring it down for an ultrasound test." they said, "yeah, I think so" but sounded a little confused!!

Anyway. I'm amazed that the thickness of the block wall could be less than 160 thousanths !!

[MR2Mania]

Talking of pregnancy, I phoned the hospital and told them, "my wife is expecting, expecting a new car, could I bring it down for an ultrasound test." they said, "yeah, I think so" but sounded a little confused!!

LOL! I can just imagine you trying to get your wife to swallow a complete engine block! =D>

Anyway. I'm amazed that the thickness of the block wall could be less than 160 thousanths !!

Well, if my maths is correct, that's just a nat's hair over 4mm thick. If you think about how thin the gap is between 2 cylinders, then 4mm is quite thick!

The average overbore is +020" (20 "thou"), which is 0.5mm. Remember though that because this is taken out of the whole bore (across the diameter), this means that you'd have to take 0.25mm off the wall alround (ie 10thou).

[llenrub]

4mm, it just seems so little. It really doesn't surprise me now. I think mines been overbored by 0.5mm even more serious!!!

I suspect this sort of thing could be an issue on any standard engine block on any car especially if you almost treble the boost!

Whilst the head is not on the car, the piston and associated part's are so I'm hoping we don't have to re-strip it to do this test.

[ENSMR2]

Hey guys, what are your views on this.

I spoke to a mate about this. He reckons that if we can get our rad fans to run for a little after the engine is off then it would still cool the coolant/water. The cool water would sink below the warm water thus moving it round the system. Allbeit at a slower rate than having the pump running.

Also on road cars for example, as part of the warm down process we could have The rad fans on a switch so that when we are coming to then end of our drive we could turn them on to help get more air at the rad especially use full when stopped at the lights.

HTH

N

[MR2Mania]

Hey guys, what are your views on this.

OK, firstly, I don't think we're concentrating on the right thing, here! After all, it's just one guy's theory that reckons a heavier cap will stop the block from cracking because he reckons it's related to the coolant temp. I don't! I think it's simply because certain blocks are too thin and collapse from the extreme cylinder pressures!!

I spoke to a mate about this. He reckons that if we can get our rad fans to run for a little after the engine is off then it would still cool the coolant/water. The cool water would sink below the warm water thus moving it round the system. Allbeit at a slower rate than having the pump running.

The MR2's cooling system has got a LOT of coolant in it, typically 2-3 times as much as any other regular cooling system, mainly because the rad and the heater matrix are so far away from the engine. If the fan running after switch down would cool the coolant enough to be able to circuit some of the coolant, I still can't see how it could shift enough to stop the engine temp from reaching 100C or above. In this case, I reckon we'd be better off just going for the uprated rad cap instead, as this would at least stop the coolant from boiling when the temp goes over 100C.

Also on road cars for example, as part of the warm down process we could have The rad fans on a switch so that when we are coming to then end of our drive we could turn them on to help get more air at the rad especially use full when stopped at the lights.

Mate, the MR2's coolant system is pretty damn good! Even with serious power engines, the coolant system seems to cope very well. At the end of the day, even if you cool the coolant in the rad a bit more, the thermostat in the engine is what controls how much coolant will flow in and out of the engine. The only times that MR2s over-heat is through corroded or gummed up cooling systems (another reason why I reckon using Forlife is a good idea, as you can keep an eye on the quality of your coolant quite easily, and can ensure that it don't get all lumpy and clogged up).

Still ain't driven my MR2 enough lately to see if the 1.3 TRD rad cap has stopped the gurgling on a hot day!

[ENSMR2]

Ok ok I'm still learning and my mate doesn't know 2's

What about a lower rated thermostat?

OK, firstly, I don't think we're concentrating on the right thing, here! After all, it's just one guy's theory that reckons a heavier cap will stop the block from cracking because he reckons it's related to the coolant temp. I don't! I think it's simply because certain blocks are too thin and collapse from the extreme cylinder pressures!!

I know what you are saying. But since it is not actually proven, and Toyota won't admit there being a problem isn't it wise to consider all factors?

Don't the japs have any more info on this? Seeming as they got the rev3 engine in their domestic market I'm sure they must have more info then we. Any one speak Japanese?

HTH

N

[MR2Mania]

Ok ok I'm still learning and my mate doesn't know 2's

What about a lower rated thermostat?

That would make the engine runner cooler at all times, and isn't necessarily a good thing. Eg, my mate Ian Ashton had a lower rated thermostat AND an oil cooler, and basically his temps weren't really reaching proper operating temps.

I know what you are saying. But since it is not actually proven, and Toyota won't admit there being a problem isn't it wise to consider all factors?

Yes, we should consider all options, but so far, there's one guy in the US thinking it's to do with the coolant system, and everyone else here in the UK who has experienced the problem saying it's something else.

Let's remember that the US only has a few Rev3s in comparison to us, and they don't really run as much boost as we do in general. Earlier gens seem to VERY RARELY have this problem (in fact, it's only one guy that I've heard of having this problem on a Rev2!).

Don't the japs have any more info on this? Seeming as they got the rev3 engine in their domestic market I'm sure they must have more info then we. Any one speak Japanese?

That's a good point. I've got a very good friend that is normally based out there, but here's over here at the moment. I guess when he goes back, he can look into it for us, by talking to some well-known 3SGTE tuners out there.

[JJ]

lol !! How the hell have I missed this post ????????

More input later.

Magoo out !

[ENSMR2]

lol !! How the hell have I missed this post ????????

More input later.

Magoo out !

It must be that Accord you have. Turning you into a proper grandpa. Eyes going funny and everything! lol

Was wondering why you hadn't posted on this.

N

[ENSMR2]

That's a good point. I've got a very good friend that is normally based out there, but here's over here at the moment. I guess when he goes back, he can look into it for us, by talking to some well-known 3SGTE tuners out there.

Yes make sure to remember to ask.

So what if you did have a thin wall block, and it is already built and running and after this thread you are really crapping your pants. What measures can you take to prevent cracking?

N