[engine_work] New Engine Build

[16v205 9]

Howdy

 

I’m like an excited little kid, its been a long time since my 205 last ran and now it has to be running on the 4th June for mapping.

It blew its engine at cadwell park nearly 22 months ago and its taken until now to finally get a bit of time and the parts sorted to start a rebuild.

When it blew up the engine was making 200-211bhp and 160 lbft depending on how you interpret the spikes in the graph, this was a standard gti-6 engine with catcams 4903108 and jenvey throttle bodies.

My original plan was just rebuild a standard 6 engine and drop it in, but then you may as well rebore the cylinders as there’s always wear when you start measuring up and I had never seen the engine run. I found many more excuses to change the spec of the engine to something I would like to have. The reliable sensible engine idea went straight out the window.

 

My new build is now this:

 

2140cc 306 gti-6 engine

Compression ratio 11.5:1

QEP 35mm 3 angle inlet valves, new exhaust valves.

Catcams Cams 4903108

Catcams single valve springs and retainers

Catcams Verniers

Custom Wossner 88mm Forged Pistons

Gti-6 conrods & Arp bolts

Mi16 88mm Crank, reground and nitrided

3.9kg Billet steel flywheel

Mocal thermostat take off and 13 row radiator

Cometic 88mm mls headgasket

Jenvey 45mm Throttle bodies

Longmans/Jenvey inlet manifold

Rover coupe 380cc injectors

90mm trumpets with variable spacers to make upto 200mm length

Emerald Ecu, Vems wideband lambda + controller

 

Think that’s about it, but first things first I had to get the old engine out of my car.

Luckily for me Anthony was over and offered a hand to get the old engine out, didn’t have to bribe him or anything. We went to my parent’s house where ive taken over there drive and garage and set about working on the car. A few hours later the engines on the garage floor and we set about finding out exactly what happened to it.

 

You’ll have to excuse some of the pics, there all taken on a phone and some are more blurry than others

 

 

 

 

We know its not a timing issue to cause this failure as the other 12 valves are still perfect. The conrod is still on the crank so the bolts havn't failed, and looking at whats left of the piston and head we'll probably never find out for sure. It does look like a valve head has seperated from the stem though, the exhaust valve stem has snapped with a perfectly straight edge about the same height youd expect the friction weld to be. But it is only a guess.

 

Have got loads of work in progress pics to bore everyone with, ill upload some more tomorrow night

 

Rich

[Doof 11]

Looks like a nice spec there, and if you're using 380cc injectors i presume you're going for big power!!

 

Sounds like my thought process originally going for a standard engine before working up to a cripplingly expensive but ultimately amazing build

 

Be interested to see how this develops!

[16v205 9]

Ive been reading your build and watched how it evolved lol

 

The 380cc injectors are a fair bit overkill, think last time I used them they were maxing 60% duration. There cheap second hand, cant remember the exact figures but less than £50 for 8 injectors a few years ago.

 

Rich

[smighall 1]

Old engine may well have failed due to a broken spark plug. I've heard of a few of these causing failures with GTI-6 lumps now.

[16v205 9]

Never heard of this with the 6's before? You got any idea what make or model plug may have failed? The plug was mashed but I put this down to shrapnel in the chamber.

 

Rich

[16v205 9]

Gti-6 Head as it came back from QEP,

 

 

Had to open up the returns from the head after it was skimmed, there was a lot of material pushed across the return holes.

 

 

All the valves taken out, these had to be removed as the cams dont rotate in the head without taking some material out. Im glad I did remove them though as I found my old exhaust valves had been returned to me by mistake. Not nice shiney new ones.

 

 

It only took a few days for QEP to sort me out a new set. They managed to get me 8 new exhaust valves on a Saturday delivery to replace the ones sent back to me by mistake.

 

[16v205 9]

Had to lap the new valves into the seat to make sure they were going to seal properly, QEP said the head retained the standard 45 degree angle. I measured the seat contact area on the used valves with a caliper and made sure the new lapped valve had the same size contact ring.

I didnt use a traditional tube with rubber plunger to do this, I went a bit posh and used a gunson ezi lap thing. Was nice and easy this way, no more swollen palms and hours of frustation as the plunger falls off the valve with a hand lapper. Also takes a fraction of the time to do each valve.

 

 

With all the valves lapped the head had another good jet wash. I then started to fit new valve stem seals. It was a pain in the arse to remove the old ones, they seemed to just fall apart rather than come off the guide. Took about 1 1/2 hours to get them off and 10mins to put the new ones on.

 

 

All the valves are marked so they go back in the same place, didnt want to start getting these mixed up as each valve is ground into its respective seat. Ive lightly lubricated the valve stems with a bit of moly grease.

 

[16v205 9]

Catcams Single valve springs and retainers

 

 

Shaped washers for under the valve springs when installed in the head.

 

 

Valve springs being installed, if you put a little grease on the top of the valve stem the collets will stick to it and not fall into the head

 

[16v205 9]

The valves all installed and looking erm shiney

 

 

Cams coated in moly grease. I prefer to use moly grease on the build where I can as normal oil will just run off leaving the metal surface without lubrication. The engines going to be rotated a few times without a oil feed whilst timing it up so it should offer some protection

 

[Doof 11]

Are those valve stem seals just standard fitment etc? I just ask as my new head has green ones like this whereas all the ones i've bought from pug have been orange / red...just wondering if they're a different spec? Perhaps the '6 ones are green and Mi ones red actually...

[Alastairh 47]

Looking good.

 

Shall be intrested to see the end power result

[16v205 9]

Are those valve stem seals just standard fitment etc? I just ask as my new head has green ones like this whereas all the ones i've bought from pug have been orange / red...just wondering if they're a different spec? Perhaps the '6 ones are green and Mi ones red actually...

 

Yeah mate just standard stem seals that came in the head gasket set. I think the headset make is BGA or similar, the ones that came off the head were also green.

[16v205 9]

Looking good.

 

Shall be intrested to see the end power result

 

And me, D Day is 4th of June so just over a week to get it in and running.

[Anthony 1,003]

And me, D Day is 4th of June so just over a week to get it in and running.

If you want me to pop up and give you a hand one evening or next weekend just shout

[16v205 9]

Tappets installed. They've been checked drained and sat in oil for the past few weeks. RTV sealent added to bearing caps and more moly grease on the bearing surface. The heads supported on a few blocks of wood as when the caps are tightened down the valves may protrude beneath the head.

 

 

Bearing caps tightened down and camshaft seals tapped uniformly into place with a rubber version of Anthony’s favourite persuading tool and a 36mm socket.

 

 

Catcams verniers fitted

 

[16v205 9]

Picture of the finished head

 

Ive a spare set of rocker covers that I may clean up and fit instead of these dirty ones. Just depends how tarty im feeling

 

[16v205 9]

If you want me to pop up and give you a hand one evening or next weekend just shout

 

Thank you, much appreciated. Ill see how it goes this week as ive finally got a few days off, you may be getting a midnight call night before mapping though lol

[16v205 9]

Bare Gti-6 block thats been bored to 88mm and chemically washed. I had it washed to clean all the crap off it so it wasnt dirty to handle and also remove the dirt and oil from the threads so stuff I threadlock in place should hopefully stay there.

 

 

Under piston spray bars. The 4 on the left are good, the one on the right which came from this block was faulty. Im assuming its a spring and ball bearing setup that is stuck open as I cant see an easy way of dissasembling them, but anyway it was open to light pressure both ways. You could even blow through it.

 

 

Piston spray bars fitted. I used a little threadlock on these to make sure the bolts stay put.

 

[16v205 9]

Picture wise it doesn’t look like I got a whole lot done yesterday, I spent the afternoon and evening gapping the rings which took hours. The wossner rings for this build had less than 6 thou gap when inserted in the bore so a fair bit of fettling needed to be done. I had a spreadsheet that Andy @ BB Performance emailed me regarding ring gaps. I settled on 0.38mm 1st ring, 0.43mm 2nd ring and 1.32mm oil control rings.

 

Lubricating the bores before starting to work on it. Hopefully it they wont go rusty in the garage while im getting this built

 

 

Top ring in place at the top of the bore, theres only 6 thou (0.15mm) gap.

 

 

Use the piston the straighten the rings in the bore and also to move them down to the centre and the bottom of the bore to re-measure the gap. Wear and taper should'nt be a problem on a newly bored cylinder but still worth checking.

 

[16v205 9]

Correctly gapped ring, you can just see the gap at the top or the ring.

 

 

Sexy piston shot I dont want to put these in there to get all dirty

 

[welshpug 1,657]

Is there a target figure or just see what it does?

 

 

no belt covers?

[16v205 9]

Theres no target figure at all, im going to swing the cam timing at emerald and play with the induction length but its just going to be what its going to be really. Id like to stay above 200bhp and have a decent torque spread.

 

As for the belt cover Anthony also mentioned this yesterday to my gf (cowbag as she's known) on msn, ive cut and chopped it a little to make it fit with the cam pulleys on. I like to be able to take the cams out complete with verniers attached if need be. The covers will be fitted and complete on the engine stand before its swung into the car.

[rapidmi 4]

nice work matey

[Toddy 7]

Has it now been on the rolling road?

[DrSarty 90 1 Cars]

Brilliant thread. Clear and easy to follow write-up and the pics are excellent.

 

I dream of driving my 2.2, and it would be nice at a meet for us meat heads with overbores (upped displacement engines) to compare motors. There are a few now and I like the fact that they're all slightly different.

 

Great .