39 replies to this topic

[GeorgeBC]

Anyone know the limits of the standard internals on the Z20LEH engine? Ive looked on astra forums and its not clear. Anyone pushed one to breaking point?

[Nev]

The rods + rod bolts are the same as the Z20LET, and are hence the limiting factor. Some engines might take 380 ft/lb for quite a while. There is no fixed limit becuase the limit is defined by the weakest point of casting which has a "random" factor. For example, If one of your rods happened to have a slight flaw in it then it might break at just 350 ft/lb etc etc. If all your rods happened to be made of perfect metal they might take 400 ft/lb. Impossible to know... If you took a Z20LEH and swapped the rods and bolts on it (for Chinese) then it would be good for a lot of abuse.... perhaps 350 BHP to 450 BHP. The weakest point would in this situation be the tops of the cyliders as the enlarged waterways are the next weakest point and can crack due to lack of metal thickness. Danger7 had his LEH block fail at this point at just 350 BHP, but I think that was unlucky.

[GeorgeBC]

Cheers Nev. I definitely want to stay on stock internals and want reliability. I wanted to hear its good to a set figure like 330bhp 370ftlb and not that its a lottery but im not going to push my luck.

[CHILL Gone DUTCH]

Cheers Nev. I definitely want to stay on stock internals and want reliability. I wanted to hear its good to a set figure like 330bhp 370ftlb and not that its a lottery but im not going to push my luck.

Reliability lol

[Nev]

Reliability is way more important than crazy power IMO; the problem is that the 2 are mututally exclusive !!

[The Batman]

[Bargi]

Cheers Nev. I definitely want to stay on stock internals and want reliability. I wanted to hear its good to a set figure like 330bhp 370ftlb and not that its a lottery but im not going to push my luck.

Have you sorted you issues with overheating I think it was? Thought I saw you post you still had problems even with the new ECU?

[GeorgeBC]

Yeah overheating was last years problems. Turned out the car was leaning out and creating heat. Fitted a cc as well but fuelling was the issue. Ive had intermittent starting problems since last years national where the car wouldn't start but then fixed its self. Did numerous trackdays, got me to france and back with no bother then wouldn't start again on the way back from knockhill. Called the AA and the fecker started when he turned up. Anyway ive only recently finally found the issue. I had a loose earth strap. Recently at Blyton my car had problems because of what turned out to be a boost leak from a failed recirc. I have an uprated recirc with no diaphram so didn't think it was possible for it to be at fault but it turns out the O rings in it are fcuked. Cars in for mapping and some other tweaks to the whole standalone package to get it just how i want it. The problem now is that now my earth strap and recirc is sorted the car wants to make more power hence my question of how much the stock internals can take. Ive asked Chris the mapper to back the boost off a bit to cap the power. Should have it back sometime this week and im looking forward to putting any reliability issues behind me.

[rob999]

Let's hope you have a trouble free year George. Be good to hear a longer term review of DGs standalone package.

[GeorgeBC]

Let's hope you have a trouble free year George.
Be good to hear a longer term review of DGs standalone package.

Cheers. Hoping to get a couple of trackdays in over the next couple of weeks which will involve a fair few road miles. Ill be on the peaks meet as well so after that ill put up a full honest review of how the car is. They seem to be pulling out all the stops to get the car perfect for me so im confident it will be all i thought it was going to be when i first collected it.

Cant believe my little turbo wants to make so much power. No chance i could go for a Klassen inlet manifold and have it mapped to its true potential with stock internals so im just going to enjoy it as it is.

[Duncan VXR]

You worried about that peak of 400ft/lb torque :-D Car is making a lot more midrange than before, the old recirc had certainly been killed ;-) See you next week :-) DG

[Duncan VXR]

And on rollers than run at least 10bup down on cs etc ;-)

[Darcini]

Duncan, can rods be changed with the engine in situ?

[GeorgeBC]

Not just me worried then Nigel

[Duncan VXR]

Yes, but head has to come off also DG

[CHILL Gone DUTCH]

You said no more mods this year George

[GeorgeBC]

Im not. This was last years mod!

[CHILL Gone DUTCH]

I will give you that 1,

[Darcini]

Not just me worried then Nigel

Paranoia is catching....

Yes, but head has to come off also

DG

You up for it then Dunc? Wouldn't be for at the very least a month or two, need to remove them from the old LEH first, oh and the cams too whilst I'm at it.

[Duncan VXR]

Nigel my old friend between 2nd child in approx 8 weeks and full steam ahead with Vag conversions and zacs beast in the garage atm time is against me and with a wedding in oct. Give us a call, be good to catch up ;-) DG