Alex's v8 re-build thread warning pic whore inside >:)

[Simon350S]

Gutted, but it was never going to be a happy story to tell I guess.

Good luck is all I'll add to this painful topic!!!

[steve930]

Alex you're a day late on the pics !  

 

If the cams are turning freely, then i'm guessing its either a bad idler pulley, belt tension or bad belt?

 

Might be worth checking the tension on the other bank out of curiosity

[red vtec]

If its a faulty belt, could you not claim against it? My friend had a 308gt4 that the oil feed pipes went on, he claimed against them for an engine rebuild.

[Bibs]

There's no contractual relationship with the manufacturer, it's with the retailer.

[redshift]

Just realised that it was this V8 after replying in the other thread. What a bummer after all that work!

 

Difficult to see from the pics but it looks more like something stopped a cam (or both) dead and that stripped the belt?

Neither of the cam gears have moved?

Might also be worth checking the turbos in case of failure and ingested pieces?

 

A sorry sight

[Alex Carter]

Well so far gents a specialist is looking at it and writing a report the tensioners and idler pullies are all new and not seized also the tensioner s are tight and in the same location luckily the other side is un damaged so that is the tell of whats happend more to follow after the report .

[steve930]

@budsy. in a certain part of the engine revolution the belt does go quite slack on the v8.

@Alex, I'd still want to be getting the Clavis gauge on the good belt just to confirm correct tension?

[Alex Carter]

The belts were installed by a lotus trained technician with a clavis guage correctly I was not going to do this part I wanted it done correctly .

Buddsy please dont post things from my photobucket without asking first .

And yes the belt is still intact but very loose .not how it was left .

Lotus technician . 2 other mechanics with 40 plus years of experience and a guy who rebuilds ferrari and lambo engines all present at the belt stage as im a little paranoid and all confirmed it wasnt that loose after installation .

[Alex Carter]

No its to do with the fire stroke depends on the cam position and which way the valve springs are heading pushing down or pushing up . Its why you must tension 1 side at a certain degree and then rotate the engine to another set degree and then tension the other side

[red vtec]

I noticed reading earlier in your posts that one belt had gone on tighter than the other, something to do with locking pins? But you had looked at it with a lotus tech guy and redone them with the valve covers off? Could this be part of the problem.

How easy is it to get parts for these engines? I do feel for you with all the work and expense that you have put in.

We're your belts from the same batch? Just trying to think what may be the cause.

[Alex Carter]

I had the same issue as buddsy at first the thought of timing in two places I couldnt get my head round I thought this doesn't make sense there all attatched why is one slack and one tight . The answer as I explained is simply the difference as they call being on the rock the difference between the cam depressing the valve to open it a tought belt and the other cam then being pushed or rotating upwards with the valve shutting putting a push force meaning one belt will be tought and one belt being slack . And then with the certain degree rotation the first belt going slack and the other tightening up .its all just to do with what the internals are doing ie squeezing or blowing .

No probs budds I left that out on purpose as it was the tell of whats happend

[Alex Carter]

And not intended for public release other wise id have posted it

[Simon350S]

Alex you have left your photobucket account open and public so anyone can look at any of your photos very easily.

I'd suggest if you'd not like that happening that you adjust your privacy settings accordingly.

I have done this to mine. I clicked on one of your photos in mobile view on my phone and it took me straight into your open account like it did with buddsy.

[Alex Carter]

Oh I have nothing to hide simon and im not bothered by people going to look around I just didnt post those photos for a reason thats all but buds apologised so no worries

[t70]

I don't even know what to say.. this is such an awful story. I do have a side note to add though.. you do not need a super expensive clavis gauge. I have been using a guitar tuning app for my iphone for a long time.. and I have compared it to the results of the Clavis Gauge and its within 1-2 hz. There are a couple of things that can go wrong when doing the belts and the engine build though. With the central timing gears (the bottom ones) you MUST MAKE SURE THEY ARE COMPLETELY DRY when you install them and you don't use any type of locktite on the bolt that holds them in place. You also must ensure that the intermediate plate between the two gears is also completely dry and free of grease. If you don't.. you will experience slippage and you will have a total engine failure. Next.. another common mistake is not fully cleaning the Loctite 572 out of the actual camshaft bolt threads. Run a thread chaser through the cams and clean repeatedly with brake cleaner and compressed air and thread chase again. Any oil in the journal is not a good plan. The other precautionary measure is to run the engine up to temperature and then re-check the tension and check the cam gear position with the tolerance pins again. I always triple check the tension and the cam positions.. And.. I have had to re-adjust tensions afterwards. Now.. I have also seen significant slippage on the intake cam on the right (UK drivers side). I don't know why this cam is the most common to slip.. but I have seen up to 1/2 tooth of slippage over time.

[Alex Carter]

Thanks for the imput mark I feel the problem is a simple one though but wont be saying here at the moment . The cam threads were tapped to get rid of old glue and cleaned thouroughly I used new locktite on instalation and this section was over seen by four mechanics and installed by the lotus technician . As I said this was something I didnt want to attempt and needed to be done right . As per a guide to fitting the re tightening of belts isnt good practice the first tension and correct hz is where its left you shouldnt tighten again youll just stretch the belt to much risking it snapping . This has been discussed with all parties concerning my engine . The engine was cleaned fully so were all pullies and belt runs it would be pointless me cleaning and painting gearbox mounts if I where just going to leave the most important part to chance and risk of snapping or slipping

Also the chance of something going wrong is few and far between but on the off chance I use an approved current calibrated clavis guage a lotus technician does the belts and tightens them correctly should something happen like what has theres other things to look at rather than improper equipment used or incorrectly fitted means I have comeback .

[Alex Carter]

Well buddsy id rather raise the issue with the proper people first rather than keyboard worrior fasion over the net the only people need to be concerned will be informed dependent on there reply or lack of well quite simply we'll go from there but thats it for now . If I just slag people off from day one the damage is done and I wont get help from anyone .

[Alex Carter]

well the photos ^ up there buddsy are with the cam covers removed to inspect the belts when the covers are on nothing lands on the belts. i have seen people talking about catch cans and so on but my v8 doesnt breath heavy and havent had the need for a catch can ? . its a bad sign for an engine to have high crank case pressure thank god mine does not .

 

 

ive had some time to do some stripping and the damage is well eye watering . warning bent metal follows 

 

pistons

 

 

 

 

good head 

 

 

good pistons 

 

 

 

diy liner sealing what a mess from the guy before .

 

 

 

head doesnt look too bad valves a little worse for ware 

 

 

in the man cave ready for stripping

 

Edited November 24, 2013 by Alex Carter

[j900jpw]

Hi Alex,

 

Wish you well with the rebuild, you have really been out of luck. Just incredible that more than one set of trained eyes all missed something during the cam timing! I wonder if with your rebuild you will now do this yourself, after all, the pictures prove you are more than handy with a spanner or two. Sometimes, when you do it yourself you know its done properly. My guess is maybe the cam timing disc that is put on the crank moved / was not positioned right resulting in the tensions being set correctly but with the camshafts in the wrong position. I hope you discover what caused the failure as piece of mind.

 

I'm about to change the belts on my V8 once I have all the parts from Lotus. This is the first time I will have attempted this on the Esprit - I have done numerous other cars. If i'm successful (I better be!), I'm in Bedfordshire and wouldn't have a problem coming down to Swindon if you think I could be of assistance if you decide a cam belt DIY route.

 

Cheers

 

Julian

Edited December 4, 2013 by julianwhite

[Alex Carter]

Thanks julian it wasnt the installation that was the issue the car did 4000 miles of happy driving before this and it went like a train if it were out on the timing it wouldnt start lt alone drive well . It would be lumpy and have no power .im pretty sure I know what the faliure was im still on the case but for now I need to find parts and begin a re build forging as much as poss. Failing that ill put an ls engine in it and go for 5-700 bhp

Edited December 5, 2013 by Alex Carter

[j900jpw]

Hi Alex, unaware about the 4000 mile bit. Just to confirm what I mean; the timing itself would not be out as this is set by inserting the pins in the cams and crankshaft, locking them in place at the point off sliding on the new belts. However it is vital that the belts are not tensioned in this position. The crankshaft must be rotated (in the direction the motor runs) by the appropriate number of degrees which differ for each bank. Only when the crank is at these new positions can the belt tension(s) be set. The engine must also be turned several revolutions after tensioning back to the appropriate number of degrees and the tensions checked and re adjusted if out of tolerance. I agree with you about the engine not starting if the timing was out. In fact from what I understand the V8 is a "close" interference engine; if a camshaft sprocket is just one tooth out of alignment, there will be piston to valve contact. 

 

Assuming the tensioning was done 100% correctly using the correct components and assembling correctly with attention to detail; e.g. putting on the idlers the right way round - numbers on the bearings facing away from the block; tensioners\block mating surfaces completely free of oil, new fasteners etc. On your engine, the non broken belt looks very loose.The belt either stretched (a lot! in 4K miles) unlikely or the tensioner backed off. The broken side; the same - it got so slack that it "snatched" or the belt jumped and few teeth causing piston valve contact jamming the camshaft momentarily. Hopefully when the time comes you will be able to let us all know what happened.

 

Good luck in sourcing the parts you need.

 

Cheers

[Alex Carter]

Yes julian all of that was done by my lotus technician and yes its a god send the other side stayed intact so we could see how lose the belt is and the tensioners were still tight not backed off or lose .

[rizla603104]

Hoping that the rebuild goes well.

[j900jpw]

Hi,

 

Its the belts then.... I have some in a box that I'm about to fit. How do you tell they are not made from elastic bands?

 

Cheers

[Alex Carter]

Well this is the million dollar question that really takes the P . I have spoke directly to gates about this and a guy I emailed from the states said he had done some lotus belts himself and you fit as per the manual and leave alone fit correctly tighten once . Then I phoned a specialist who said they install , tighten the belts turn over a few times check again then tighten again . Then I spoke to a bod at lotus who said they install tighten turn over by hand tighten then start engine tighten and then after a few miles check and tighten again ! So as discussed with my buddy ross it seems to be a black art . You ideally risk the chance of over tightening if you check and re tighten so the belt snaps . Or if you do as per the manual you could end up with a lose belt like me if you do it once and leave it. So honestly julian I have no clue at all so when / if I do it again ill let you know