Gutted cracked block AGAIN :-(

[Chris]

Good stuff mate. Just remember silly stuff like ecu, looms if you butchered yours, fuel lines if you changed out, fuel rails, injectors.

Well you get the idea

[GTS GAV]

Sorry to here this geeman im always gutted to read/see members go through this, i am not looking foward to the day it happens to me one bit i may just loose the plot if im hounest lol.

But i agree with what others have said its all down to the cooling and map. Did you ever consider fitting a W/I kit as imo and this is just my theory i think it will drematicly reduse the chance of this happening, im deffantly fitting it to mine, but it is proven fact that its just pot luck but im really hoping luck is on my side, i no i will be nervus about this every time i giv it the beans and will probably in the end force me to sell up, i have basicly andyf's old setup bar im running hks 264' cams rather then stock rev 3's, i will be deffantly fitting a motec m4 and will also have a mapp by mr rowe so fingers crossed

[greeny]

Where did you crack it lad?

In all honesty, id go late 5s block now and not worry about it again.

Not 2 sure yet mate as the engine is still in the car. But it over heats once you pull up after giving it a boot full or on a longish motorway drive.

I was on a stock rev3 head.

I thought 1.5 bar was ok and anything 1.6+ was the problem. It's luck of the draw I guess as people on here have run 2 bar + and never cracked......

I remember Rogue saying on here that they've had totally stock blocks crack? I think alot of it is luck, and how good the cast was when it rolled off the line! And didnt Dale have an N/A block crack?

If your going to sleeve a 3s block, get a 96+ 3s, otherwise you could find it then cracks on the outside. I believe the later 3sge blocks have the extra casting on the outside aswell, so you could use one of those, should be easier to get hold of aswell.

Mine was on 87mm pistons and cracked on the outside, cylinder walls were perfect, it also cracked whilst been run on race fuel, so there was more chance of me nailing holly willybooby, than a chance of det contributing to it cracking!

Have you still got the 87mm pistons? If so, find a good bored 5s block (87mm stock) a slight hone, re-ring the pistons and put it back together. That would be the way id go if i were you!

Got to remember aswell, alot of the cars that have been running high boost for years probably arent doing the track days that you do, more road cars, quick pulls etc, instead of full loads for a good amount of time, like on track.

[JJ]

Got to remember aswell, alot of the cars that have been running high boost for years probably arent doing the track days that you do, more road cars, quick pulls etc, instead of full loads for a good amount of time, like on track.

Should see the roads my way, you could have maxxed the car out everyday if you wanted !! Turn down another dual carriageway and theres roundabout after roundabout !!

All good things come to an end as the traffic police have just moved in locally !! Pffft !!

[2barGee]

Well the block has had about 10 track days thorugh it and 3 trips to the ring

That was all running on stock internals with a td06 running 1.2 bar (350bhp).

Ive not doing any track days with it running 400+ and its cracked the block with the extra power unless i had a tiny crack before and its got bigger with the extra power.

I did do a small handing circuit (30seconds) in it a couple of weeks ago and the temps where fine all day raggin it about.....then on the drive home (no boost) it overheated when i pulled up.

[Kongaroo]

Sorry to hear about your car Dan. Can't see you going back to standard though after pushing 400+BHP

[JJ]

Sorry to hear about your car Dan. Can't see you going back to standard though after pushing 400+BHP

Funny you should say that Kongaroo... when I had 2 MR2 turbos, the blue one I still have was the modified one with a big turbo on teins.... and for the track day, I actually took my bog standard Rev 2 ( boost tweek + Tein Coilovers ) to the track instead and had a brilliant day with it...

The little Ct26 is brilliant on the track even though the straights could have done with a bit more puff !!

[mr2nut123]

Ahhhh, come off it JJ. 400bhp MR2s are addictive. The more power the better

[JJ]

Ahhhh, come off it JJ. 400bhp MR2s are addictive. The more power the better

Luke you power junky !! 400+ bhp MR2s come with a price too... Noise + License !!

Whilst I still have my license, I'm starting to find the noise of it a little annoying these days... a sign of age !!

Having jumped back into my old white one the other week... I found it soo sedate in comparison !!

[Dangerous]

sorry to here your woes bud if its any consilation i,m on engine number 3 aswell !!

from my point of view on dont think sleeving is the way forward......

according to my well known engine builder the machine work needed to fit the sleeves actually weekens the block further causing torsonal stress problems which in turns causes the sleeves to drop in the block making all kinds of problems with the head gasket sealing etc etc...

If you speak to fensport they will also tell you NOT to sleeve and go for a later rev 5 block...

Ive gone for a rev5 na block x-rayed (thicker in most places) and a block girdle to prevent any block twisting....If this fails i will ship a 99 5s block over from the states....

Just my 2p's..............

[JJ]

Good advise there....

Just to elaborate on countering sleeve movement, 'top hat' design requires both machining the full bore and a wider section which interlocks the liner to the block ! Liners not going to move either direction in this case once the heads bolted down...

Straight liner approach...well shoot the engineering approach on that one !

[mrdb]

Big power and liners wont work on the 3sgte the block design is all wrong. Liners will expand at a different rate and lift head. seen it loads of times. 400hp probably the limit on road car but if used on track will lift at that power also...

fensport tried it johny milner tried it on TSS sprint car etc....

[Steve Horrocks]

As Chris, im on stock block (at 86.25 with forgies) stock had & cams and running 1.9bar. It's been built for a while now & totally fine. (and for sale, hint hint!)

Lol

[Dangerous]

Good advise there....

Just to elaborate on countering sleeve movement, 'top hat' design requires both machining the full bore and a wider section which interlocks the liner to the block ! Liners not going to move either direction in this case once the heads bolted down...

Straight liner approach...well shoot the engineering approach on that one !

hey JJ thanks....

sounds good let us know how you get on !!

I'm still sh1ting it about winding my boost up....
Currently mapped with the boost turned off (.8 bar) still making 300hp@hubs...

I'm going for a larger front alloy rad, evans coolant,water inj, external 13 row oil cooler, rear facing short runner inlet manifold...Then thats about all i can do to it for max reliabilty....oh and a side exit exhaust to really p1$$ the neighbours off !!!

[Sideways Si]

Sorry to hear that dan!, I know exactly what you've been through!. My 2nd 3s block I cracked was even sleeved, It makes no difference, If the casting isn't up to it, then it won't last..

I'm With Greeny on this one, If your goals are beyond 400+, Then the 5S is the best & most reliable option..

[2barGee]

Sorry to hear about your car Dan. Can't see you going back to standard though after pushing 400+BHP

Hi mate it won't b totally standard 300 will do!!

Interesting what everybody is saying though. It's a shame these blocks are so thin because 400+ in the mr2 is lots of fun!! I guess with my track addiction the 5s block might b the way forward if I want lots of power again!!!

[gazrev1tubby]

Can I ask what your symptoms were that led you to believe the block had cracked, also how did you diagnose it ?

[jon_st205]

Caldina/rev4 3gte block time? Drop the compression back down and bob's your auntie.

[2barGee]

Can I ask what your symptoms were that led you to believe the block had cracked, also how did you diagnose it ?

the temps would go up and down going up to around 95 then back down to 85. I would bleed the system and this would sort it out for a month or so then the same thing would happen. This got worse and worse to the point the temp would start to go crazy after a 40 min drive, coolant was also getting pushed out of the system so either head gasket or block and i carnt really see it been the gasket.

engine is out now so I will find out soon.

My new plans are already in motion...............

[dawesy]

dang dude sorry to hear that.
i running a stock rev 3 block, 1.8 bar and 470 bhp.
i cracked one block but this current one has had no problems due to a couple of mods.
first im using evans npg-r coolant and the block has been done with hardblok http://www.hardblok.com/
since then ive had no issues. oil temps are a little higher but im still on a stock oil cooler. might be worth looking at.
the hardblok kit i got was about £60 and there is enough to do 3 or 4 3 S blocks, a lot cheaper than sleeving.