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To be fair, i have always wanted to keep my car as standard as possible so i wouldn't be that interested in uprating to HC even though the benefits are clear to see! Add to that the

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Ignore the above post!

I have just had my shiney new HC pistons turn up from Lotus Cars......hhhmmm shiney :) I need to bore the block out, anyone know the correct dimensions for this?

I am not going to go the full HC conversion, just the forged pistons and i only bought them coz they were Buy it Now on Ebay at

Edited by simonf

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Andy - I'm not convinced that the casting between the LC and the HC head is significantly different (other than larger inlet ports). It seems to me that the improvements in the HC cooling were achieved by mods to the external pipework and the outlet stub from the head (both stubs are interchangeable). I prepare to stand corrected, but thats my observation of converting an LC engine to accept an HC head.

cheers Steve

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Sorry Simon but you really need that HC head to run more boost. The cooling in you LC can't deal with the extra heat and you would end up just pinging number four to death. With that said, you could put a methanol/water injection on it and increase boost. :) But that may be more than you want to deal with. Better stay with 8.5.

Cheers

Clay

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There was a cooling mod to improove the pre HC system.... I know cause I have it :)

Its a box filled with loads of rubber & ally pipes and a different thermostat along with an external expansion tank, its supposed to improve the flow and efficiency around the engine and it was just under

Chunky Lover

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Yes that makes sense to me. I think we might agree that the limiting factor, for both models, is likely to be the fuelling and ignition without an ecu. I reckon detonation, on an over-tuned car, would potentially kill the car as quickly as overheating - assuming your cooling/heating systems are in good order...

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To add my thought to the matter I dont see how the HC piston/liner set would let you use more boost? I thought the benifits were having the liners the same material as the rest of the engine to give an even thermal expansion was to help cure the head gasket issue caused with the old steel liners. Running a higher compression would lead to the need for the extra cooling. I know the latter pistons are forged unlike the earlier cast ones but that would give more strength through the structure of the ally. The cast ones being more prone to damage during impact etc BUT at the end of the day both are made of allumium with similar levels of thermal breakdown?

Basically my point being I think if you boost more you are equally likely to melt your pistons...unless you had a charge cooler.

Buddsy

 

"Belief is the enemy of knowing" - Crrow777

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Steve, yes, more fuel or else pistons will be melted away, so happy to agree that.

Buddsy, the only reason the ali liners and piston set may take more boost (note earlier I have told Simon NO to more boost) is the fact they are probably a little bit stronger, but would still be susceptible to melting if detonation occurs.

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OK guys i get the message, NO MORE BOOST!

I did think that the forged pistons could deal with an up on boost, but the last thing i want to do is another rebuild!!!! So 0.5lb boost it is then!

I have just had a PM from Brian Angus RE: the bore diameters for the HC pistons (Buddsy you might need this info later as i am hoping that you will do the bore out for me :) )

Anyway if i post them on here other people can benefit by using the search button.

If you want to bore your LC engine block out to accommodate HC liners:-

To Quote directly from 'Mr Esprit' - AKA Brian Angus

The liner bore should be 102.42 / 102.47mm (please check before boring your block out!!)

The cutter diameter 115.3mm

You should aim for a Liner Land Seat Depth of 69.750mm and this should give you the correct liner height.

Thanks Brian for the info!!

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Scott...how is a charge cooler going to stop pistons melting? I thought the idea of a charge cooler was to increase the density of the fuel/air mixture entering the engine and thus produce more power. I would think this would result in more heat being generated and thus being more likely, all other things being equal, to melt the pistons. Or are there other effects I've overlooked? We'll be on to water/methanol injection next!

Scientists investigate that which already is; Engineers create that which has never been." - Albert Einstein

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I believe the effect of innercooling, and/or water methanol injection, prevents pre-detonation (pinging). Which in turn prevents the pistons from being beat to death. In the US, where cast iron heads are still used, compression levels must be kept low because iron will retain heat and cause detonation. Aluminum will transfer heat much faster and allow higher compression. The LC head, as I understand , is not cast properly to cool number 4. The add on cooling mod really only effectively cools the LC condition, and does not uprate the head to HC. I have no personal experience with this, it is just my understanding.

Simon, Im with you all the way brother. Poor the coal to it, and lets see what is what. :)

Cheers

Clay

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John

I believe fairly much as Cley said. The charge cooler was added to allow more boost. I think the basic idea is as you add more charge (fuel& air mix) you get a bigger bang and thus more power. More heat will also be produced. The lower you can keep the temp of the charge entering the combustion chamber the chance of pinking and detonation taking place is reduced. Another factor is the distance from the turbo to the inlet. The longer the distance the more you are likely to see more turbo lag. I think one thing that is meant to be a real trump card for the Esprit was its almost lack of Turbo lag. I remember reading about some informed visitors who saw the plenum to turbo tube with its cooling fins on and said

Edited by Buddsy

 

"Belief is the enemy of knowing" - Crrow777

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Buddsy, the charge cooler isn't to get more boost exactly, it's to get more air into the cylinders with the same boost. Subtle difference and probably what you meant anyway. The idea being you get the air cooler than it was, it become more dense, so for the same volume of air at the same pressure you have a greater mass of air, thus more Oxygen available for the combustion.

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Oh is it? I thought it just cooled the charge and let you set the wastegate higher? Thats what I assumed...learn something new every day! :)

Buddsy

 

"Belief is the enemy of knowing" - Crrow777

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Could someone remind me before i finally get my car up and running, that i still have the 4mm washer in my wastegate! The last thing i want to do is blow holes in my new pistons!! :)

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You meen to say, this is the last time you are going to help me take my engine out :rofl: but we have such fun doing it andy!

If that is the case i better drive it like a vicar from now on then coz i dont fancy trying to take the engine out on my own!!

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Yes it will! As Obama said "We can fix it" (oh and bob the builder!?)

But good news I dropped off the engine crane yesterday! :D

So I expect Simon will be squirreling away as we speak!

Buddsy

 

"Belief is the enemy of knowing" - Crrow777

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Thanks for the hoist buddsy!

Is there any chance of a strap for the hoist?

Also, how much did you pay for your main bearings and bigend bearings? Strattons want

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