130 replies to this topic

[Duncan VXR]

Rob I have not held the CS cast manifold in my hands yet so cannot comment on construction but surley better than the oe design I agree with you from what I have read so far and biggest benefit will be that bi old steel block

[siztenboots]

where does the PCV vent pipe fit in amongst that? Also the manifold flange does not use the girdle bit?

Edited by siztenboots, 29 October 2010 - 09:14 AM.

[Duncan VXR]

PCV = positive crankcase ventalation for anyone not sure. Steve not sure if it needs modding, certainly dont want it too close to that heat source 5 mins work if it needs modding though DG

Edited by Duncan VXR, 29 October 2010 - 09:33 AM.

[siztenboots]

actually thats very similar to this setup

T3 inlet housing with Internally wastegated 5 bolt discharge

[danger7]

Hello,

What size pistons are you specifying for your engine rebuild. Machining the bores out on an LET can lead to dangerously thin walls between the water galleries. I exploded an Z20LEH block which cracked and blew out shrapnel due to running 1.4 bar boost pressure. The max piston oversize escapes me 80. someat I'll check and cosworth is Mahle and OEM pistons on an LEH engine are very very good. I'm running an LEH cylinder head with LEH bottom end internals with a C20LET block with a Garrett G2871 bolted onto a custom exhaust manifold no AMM ecu runs off lambda and air temps.

Cheers
Ian

Danger, thanks for your feedback.

Are you saying that the CMS Cosworth and Mahle pistons are exactly the same and produced identically?

If I were to source a C20LET block, would this mitigate any issues of "thin walls between the water galleries"? What other implications, pro's and con's are there with substituting the block and non of the peripherals?

Zach

Hi ya,

Ok pistons sizes 86.00 mm standard max oversized 86.50 mm that's what has been suggested the C20LET block has more material between the bores and so in theory its stronger (heavier too) its used here in Germany extensively by tuners who go north of 450 bhp, Markus of Vmax runs 700 bhp with his C20LET blocked fire breathing only good in a straight line M3. All pick up points are identical , my crank is from an LEH so to are the rods and pistons.

The Mahle piston is different to the Cosworth design so its price and performance related I guess, I know the Mahle is squeeze cast and skirted and is a very very good piston with the ability to handle 400 bhp, Cosworth I dont know but it should be good. Cosworth has had a hand in the design of the LEH engine and along with Lotus Engineering we've got an engine which is basically very sound. Oh the cylinder head is cast at Wocester by Cosworth I'm such an anorak

Cheers
Ian

[zebwach]

A little update with regards to the freezing. I managed to get hold of 'Frozen Sold' today. Their process involves them taking the components down to -192 degrees C and maintaining it there for a prolonged period of time. This is also done in a slow controlled manor and not simply dipped in liquid nitrogen as I first thought. I was quoted the following prices: £250 + VAT for the block £155 + VAT for all the connection rods and pistons The process take them one week to complete. I shall definitely be having this process carried out on at least the block. I don't think there is much point me having the rods and pistons exposed to this procedure for my application, as they are already rated way beyond the power that I'm going to. But I'm thinking I may have them done anyway purely for the piece of mind that everything is being done as thoroughly as possible while its in bits and that it is relatively inexpensive.

[Duncan VXR]

For that money I will leave them in the freezer for you Well managed to get half a day to make some progress and clam off, all wiring loom disconnected, all hoses off and just oil / gearbox oil to drain and pop shafts out and mounts off and engine out Can then get it split ready for the freezer and machine shop and hope to get a day off work this week to get it all done pending the baby does not arrive DG

[zebwach]

Small update. The block is definitely machined before freezing! Duncan has sent me some pictures of my disassembled car. Its nothing people haven’t really seen before, but I shall post them up later. Duncan as also just phoned me with a list of dirty, sexy things he is also going to do to my car to make it even faster. I'm very excited!

[MrSimba]

All got very busy round at 'DG Developments' today



Nearly got a bit 'heated' over who got the 'ring mug...



Paul getting stuck in



Zach thought he was getting a Garrett not a Dudley... BDP waaaaaaaaaay better than BHP!

[VXT Tim]

Don't let this guy touch your car

Someone please hoover that sound deadening on the firewall, I'm having palpitations.

Edited by VXT Tim, 05 November 2010 - 04:10 PM.

[siztenboots]

do the fuel filter service now, its a major pita otherwise

[Duncan VXR]

Thanks to MrSimba & Paul for popping round Even if Simon turned up 15 mins prior to engine after I did most the work and Paul 5 mins before it came out :D lol Let them loose with some jobs on the stripping of the engine, splittin gthe box and as always plenty of chit chat. Paul got the Nurburg mug twice on the coffee feeding and think Simon felt left out Fuel filter done before when servicing the car but yep now would be the time if not machine shop was closed half day so just gave up after splitting most of the engine, lots of parts in the post Monday and get the besatie back together and back to zac asap. So will clean things up tomorrow and take the crank off but other than that nothing left to do until monday DG

[zebwach]

Wow guys! Thanks for lending a hand, lunch is on me at the waterman. I feel a little left out. Im afraid im going to have to protest to the Dudley mod. Im planning on using the car for the occasional track day and there is no way it will pass the db drive by test with him in place of the engine! I had the PA tank and uprated pump fitted a few months ago, the filter was changed then. Zach

[MrSimba]

Im afraid im going to have to protest to the Dudley mod. Im planning on using the car for the occasional track day and there is no way it will pass the db drive by test with him in place of the engine!

Good point Zach... He's definatly louder than 97db's

[Duncan VXR]

At a guess 110db, will measure one day - anyone who has met the now famous Dudley will know he has a very loud bark and is well...........................a bit crazy DG

[VXT Tim]

I take it Dunc has been a bit too busy to progress any further. I can almost hear Sarah "where do you think you're going"

[Duncan VXR]

Managed to fix the barage on my 2 week break but not much progression on Zacs car........I think it is fair to say I have made Sarah HATE all things cars lol I did have this weekend allocated to build the engine but as per below no need now There have been some changes and the cosworth pistons are no longer been used and few other minor changes but Steve (who is doing Nev's) engine is actually doing the build now as he was fitting the diff to his box anyway and was going to do the machining of the block and balancing etc and tbh if your that far in you might as well put it back together so saved myself a day in the garage - all about delegation and Steve seems a really nice guy who knows what he is doing So hope to have the engine back in a couple of weeks and will get it stright back in and back together for the engine to be ran in and then back to fit the garrett and mode the exhaust for mapping and either trailor it down or very steadyt run or tweak the map - look into it nearer the time Got a few things backed up so may play fabricator possibly saturday and get a few things moving and Harry keeps stalking me about a few jobs on his so prob do that also and make a xmas list for new tools I dont have, lost or broken them Sure Zac will update a more detailed breakdown of spec for engine now Hope you all missed me for 2 weeks DG

[jameso]

Nooooooooo not Dudley!

Edited by jameso, 29 November 2010 - 01:21 PM.

[zebwach]

Quite a lot has changed regarding the specification of the build since my last update. Firstly, the money that I had allocated for the freezing of the block, rods and pistons has been redirected towards the refurbishment and insertion of a VX spec ATB into the gearbox. I felt that this would be a better use of the money. It also speeds the build up slightly as there is less shipping of parts involved. Secondly, Duncan has returned the connection rods, Cosworth pistons and water pump(it was U/S) to CMS in favour of some Arrow rods and Mahla pistons. This change is due to a little research and digging regarding the thermal expansion of different alloys in relation to their casting/forging method. For my application as an everyday car, it turns out the Mahla are more suitable for me as they change dimensions with heat a lot less than the Cosworths. To the extent that the cylinders can be bored out to twice the tolerance than they otherwise would be. For long runs and track use, I’m sure the Cosworths would be fine, but for everyday use and short journeys piston slap would have been likely. The change to Arrow rods was purely a decision based on badge snobbery and that they are the best you can get! The change from machine shop to Steve Milton was not only based on a considerable financial saving, but also his vast knowledge/experience and willingness to talk for hours on the subject. He picked the engine and gearbox up from Duncans on Saturday and should hopefully have returned it in approx 2-3 weeks. So I may get here back before Xmas with a little luck for the tedious running in process. The decision for Steve to rebuild the engine and not Duncan was made purely on the logistics of Steve already having the bits and pieces there, and there not being a lot of extra work involved for him to torque a few bolts up rather than label all the parts up for Duncan to do it at the other end. I have just come off of the phone to Steve and he has reported that the insides of the block are in mint condition, which is good considering that my engine has done 67k. It just shows that it does pay to let your engine warm up thoroughly before giving it billy big beans! He also says that he is going to trace the serial number, on the bottom of the piston, back to Mahla to see what alloy and forging process was used. There is a rumour going around that some/all of the LET pistons are the same as the aftermarket ones that you can buy from Mahla(the original supplier). He will check and cross refer this with weights etc. This would be good for 3 reasons: Money saved by requiring less machine work No need for new pistons. Again, money saved The engine wouldn’t require running in to the same extent Don’t get me wrong, if there is the slightest difference or sign of wear and tear, then I shall not be using this route as a way of saving money. Either way, the piston shall be machined for a slightly lower compression ratio. Once again, a huge thank you to Duncan and Steve for their efforts. Zach

[VXT Tim]

Good update, all sounds exciting and that it is coming on nicely