Serious trouble V8

[Guest modifiedv8engines]

It is that sort of noise Mike and could be the heat shield ....

I changed those for the genuine Lotus items a few years/not many mile ago and since that part is exposed to the elements, chances are it is that part. Must admit had the face as long as a horse yesterday when that noise appeared and even with sunshine, it was pretty cloudy around here. Phew .......

 

 

[mike_sekinger]

The Lotus heatshields are made from very thin stainless sheet - they will fail time and time again.

Ramspott & Brandt offer a thicker gauge equivalent - but they are not super cheap (like everything R&B).

[Guest modifiedv8engines]

Thanks for advising an alternative Mike.....seem to recall this is an engine out job for access so perhaps a temporary "repair" of some description will suffice.

Possibly stainless steel washers spot welded to reinforce the mtg holes would do it .........will see what I can see with my bore scope as cant see much from the top or even under the engine compartment.

 

[Guest modifiedv8engines]

Checked this afternoon and not the heat shields ........car started, ran to temp to cycle fans and not a rattle not even a whisper .....nothing, nada, zilch, zero, nothing  

Mysterious noise has gone but no doubt will reappear when I least expect.

To make life easy used a £5 telescopic mirror with a LED light .......ebay purchase and worth every penny.

 

 

[MD355]

Today's update !!!

I went to my mechanic to make a list of parts we will be ordering, while my crankshaft is currently at the machinist being fixed.

According to the machinist's specifications, we need A918E0017F BIG END SHELL + 0.50 mm   (16 units) , A918E0014F UPPER MAIN BEARING SHELL + 0.25mm  (5 units) and A918E0015F LOWER MAIN BEARING SHELL + 0.25mm (5 units)

While the +0.25 mm are available, the +0.50 mm units for the conrods are not longer produced and here we have a problem !!!

Either make a new crankshaft or find from other brand... Somebody suggested that Audi engines use similar bearings for conrods...

So now, we have to wait until Monday for the machinist to have an answer if we can make do with 0.25 mm bearings for the conrods... Let's hope !!!

Any ideas / suggestions are welcome !!!

 

[mike_sekinger]

Not a surprise there.   If the crankpins (BEs) can be re-worked to the 1st level of reclaim, then you're fine.   If not, then as hinted you can use a Audi application but the shells need to be adapted to the correct width - meaning that you will need to machine off some of the bearing.   If you are forced down this route, the good news is that the bearings can be sourced in with hardened steel backs, meaning that they are stronger.

I have several sets of these shells already machined, but if you want to make your own I can give you the ACL or King Race part numbers.

PM me if you need an engine set of shells in +0.50mm

[MD355]

By the way, since I am doing a rebuilt, what are the pros & cons for forged pistons ?

Can anyone suggest where I can find them in Europe (I don't want to import from the US for import tax reasons) ?

Thanks !!

[mike_sekinger]

SWLC have forged pistons - several sets on order right now.

Pros - stronger, lighter, precision and quality

Cons - should be obvious.... but your need to check carefully for correct sizing with your liner grade and necessary skirt clearance. The pistons are on the high end of the OEM size grade.

You should be checking if your current liners are fit for reuse.  If not, then get fresh ones.

[Daniel]

This sounds very much like the mechanic getting his excuses in early for an inevitable failure, after which he can blame Lotus and tell you he told you so.

Having blown up a V8 following some previous owner shenanigans I’m Sympathetic to your story but I agree with others on this: take it to an engine builder with experience of these engines.

I've just had my fairly simple 907 N/A 4 pot rebuilt by one of the more recognised specialists out there and it didn’t cost the earth, but I know it’s right.

[CharlieC]

On 21/06/2019 at 17:02, MD355 said:

My mechanic explained to me that it was the furthest way point from the oil pump that failed...

He showed me the oil pressure release valve that was stuck !!!

Have you got a pic of the PRV? 

This is how mine looked after a similar failure. 

 

[MD355]

Mine looked very similar !! It looked like black/burnt in a similar way !! It was stuck to such an extent, that it needed a hammer to move freely !! After cleaning it slid better, but still I am ordering replacement !!

[MD355]

4 hours ago, mike_sekinger said:

SWLC have forged pistons - several sets on order right now.

Pros - stronger, lighter, precision and quality

Cons - should be obvious.... but your need to check carefully for correct sizing with your liner grade and necessary skirt clearance. The pistons are on the high end of the OEM size grade.

You should be checking if your current liners are fit for reuse.  If not, then get fresh ones.

How do you know if the liners are fine for reuse ?? Is there something to check for the forged pistons or do you just order the CP ones and they are perfect fit for the Lotus V8 ? What about the piston rings ? Do you just buy the standard set for the V8?

[mike_sekinger]

Your engine builder will assess the condition/suitability of the liners, both for size and for surface finish.  The CP Carrillo pistons are supplied together with rings and are manufactured to one size specification - dia. 83.00mm.   The OEM liners and pistons are supplied in two size variants.   The engine builder will advise you if your existing liners are suitable depending on the measurements.  He may advice just to re-hone the surface or that you need new liners.

It's not magic - just normal things to check when considering an engine build.

[MD355]

Thank you Mike for your advice !!!

Now it’s decision time !! Lets cast a vote !!

who is in favor or forged vs keep oem ?

The cost is a factor but my main concern is availability and delivery time !! If they are available at SWLC right now, I am seriously  tempted !!!

[mike_sekinger]

Seriously?.... a vote?  Why?

If you are wanting higher power, then forged pistons would be necessary - along with other upgrades.

If you want stock power, then stay stock.

Forged pistons will not make your engine 'more reliable'  in stock form. 

Unless you what more power or just have to have forged pistons for bar-talk, then why fork out the extra money?

You biggest concern should be getting a good solid build.

[Barrykearley]

You’d be better off buying a 4pot 

[mike_sekinger]

How can we ban you from V8 threads?....

[Barrykearley]

Maybe one day I’ll get another 😬

[MD355]

1 hour ago, mike_sekinger said:

Seriously?.... a vote?  Why?

If you are wanting higher power, then forged pistons would be necessary - along with other upgrades.

If you want stock power, then stay stock.

Forged pistons will not make your engine 'more reliable'  in stock form. 

Unless you what more power or just have to have forged pistons for bar-talk, then why fork out the extra money?

You biggest concern should be getting a good solid build.

You are right !! In principle, I like to have options !! Which means that right now I might not want extra power, but in the future who knows... My primary concern is RELIABILITY !!! I am fed up of my car breaking down after 1 week of driving !!! Overheating is another concern that I have if I increase the power !! So for now lets do a solid reliable rebuild !!

when i bought my car the only mods it had was two blow off valves and a modified ECU (that I think injects too much fuel). I added straights pipes decat, and k&n performance filters !! I don’t need extra performance !! I enjoy the fireworks in the back and want realiability !!

so I found somewhere (but not currently available) the forged piston set for GBP 1200 excl VAT. Its not cheap, but not hugely expensive either.

what do you think I should do? Is there current availability in SWLC ? Thanks

[Barrykearley]

@MD355 that engine needs rebuilding by someone experienced with these units. They are much like any other engine yes - but have their own quirks. You only need to search on here for the issues folks have had with head gaskets immediately following rebuild to paint a picture.

[Daniel]

Absolutely. Crate it up and send it off. Meanwhile your guy can be busying himself with making sure the cooling system is flushed and clean and your car is ready to receive its fresh reliable unit.

I’d ditch the ECU for a stock unit personally too.

[Barrykearley]

It shouldn’t inject too much fuel - it’s got lambda sensors which should stop that occurring??

unless you are willing to invest serious funds in the car modifying gearbox and all the other stuff around and in the engine - then you should keep the lump standard or risk a future failure.

if and when I buy another that needs an engine rebuild - then Mikes the man 👍

[MD355]

On 30/06/2019 at 20:29, mike_sekinger said:

Your engine builder will assess the condition/suitability of the liners, both for size and for surface finish.  The CP Carrillo pistons are supplied together with rings and are manufactured to one size specification - dia. 83.00mm.   The OEM liners and pistons are supplied in two size variants.   The engine builder will advise you if your existing liners are suitable depending on the measurements.  He may advice just to re-hone the surface or that you need new liners.

It's not magic - just normal things to check when considering an engine build.

Hi again !! How do I know if my piston liners are suitable for the forged CP pistons ? Can I know in advance or do I need to bring the pistons first ? Any measurements ? Thanks

[mike_sekinger]

Hi,

According to the spec sheets, CP Carrillo pistons are 82.941 diameter with surface coating,  for a planned bore of 82.9996 (83.00mm) - the OEM dimensions are in the manual which your mechanic will need to reference.

The size grade is visible in the piston crown (A or B).  Your builder will measure the liners and check if they are suitable for the Carrillo piston after any re-honing that may be necessary.

Grade A B Bore Ø 83.015 83.030 83.000 83.015 Piston Ø 82.990 83.005 82.975 82.990

[MD355]

Thanks for the details !!! That's very helpful !!

So, excuse my ignorance, but is grade A or B the desirable setup to have for Carrillo Pistons ?