[engine_work] 2.2 Gti6 Engine Build

[marksorrento205 80]

Great stuff. Looking forward to my passenger ride

[Mad Scientist 106]

Well, time for an update I think.

 

I am starting to think I am jinxed! Read on...........................

 

 

I finally got a call from the machine shop last week to say the pistons were done and it was all ready to be collected. They had to dummy build and take apart the engine 4 times to get the thing spot on (or so they thought!). In fact, despite me not asking for them to, they reported they had fully assembled the bottom end ready to go!

 

HOWEVER.....................When I got there, I got talking to the guy who had done the work, and unfortunately, he had done it wrong! There were a lot of initial discussions around compression ratios before I finally settled on 12.7:1 to suit the new planned cams. As a result, there was the original job card, requesting a compression ratio of 11.5:1, and the new job card with 12.7:1 floating about.

 

You've probably guessed by now, that the pistons were machined for an 11.5:1 ratio in error.

 

This really was a genuine mistake by 2 guys with a very good reputation. They have already ordered another set of pistons to put it right, and of course, they are picking up the tab. Problem is, its put things back another 3 or 4 weeks. On the plus side, I should have another set of pistons to sell!!!

 

Further to my misery................

 

Colin's TIG welder died just before Christmas, and just before he welded the manifold up. Its done now though, but he's still sorting the strut brace. However, in light of the piston issue, I told him yesterday there is no rush.

 

 

The main thing is KEEP CALM AND CARRY ON! I will not be beaten!!!

 

Still working on cam profiles and have talked to just about everyone in the cam industry now! Nearly there I hope!

 

 

In other news, I have a new subframe from MarkSorrento205 which I have had blasted. Its going to be seam welded and adapted for the sump guard. At least this will give me something to get on with!!

 

[harryskid 193]

Chin up , don't let the buggers grind you down !

[petert 586]

Why did you want 12.7:1? What fuel are you going to run it on? I think I'd have been happy with 11.5:1 if running 98 RON.

[Mad Scientist 106]

I will be using 99 ron, with some booster for peace of mind if needed. However, the static compression ratio was worked out based on the required dynamic compression for a 300 ish degree advertised duration cam. It was also suggested as ideal by Sandy and Guy Croft. I take it you don't agree Peter?

[petert 586]

No, not at all. If you've done the calcs using stroke, rod length and inlet closing time, and considered fuel, then you're probably correct. I'm just getting up to speed on the build. You've certainly had a time of it! We have some interesting fuels over here now, as I'm sure you do. As a replacement for avgas, racers are turning to E85 racing fuel.

 

http://www.fuelcontrol.com.au/

 

Rather than being a blend of 85% ethanol + 15% 91ron, as sold at the pump, it's blended with 98 ron, making it 108 ron. It would be ideal for your requirements.

 

You will certainly need a late closing inlet when using 12.7:1.

 

What's your rod length?

Edited January 11, 2012 by petert

[marksorrento205 80]

On that plus note we both know where the old pistons are going to end up

[Mad Scientist 106]

eBay!

 

Sent you a PM Peter. To summarise on here for those interested:

 

Rod length is 152mm.

Closing point for inlet will be c. 78 degrees ABDC when fitted, depending on final cam spec obviously.

[welshpug 1,657]

spare pistons eh? will they fit S16 rods given they need 152mm long ones?

[Mad Scientist 106]

They will Mei, but Mark has already etched his name on them! Sorry!

[welshpug 1,657]

vandal

[Mad Scientist 106]

UPDATE:

 

The cams are now sorted! After much research and discussion, the perfect set came up second hand!

 

Unfortunately, they need so much room around TDC that the valves may need to be recessed a little more, so the head is off for another holiday in Cornwall!

 

 

Bonus points to anyone who can guess where the cams previous home was!!??

 

[stu8v 68 1 Cars]

lawnmower?

[Mad Scientist 106]

http://www.telegraph.co.uk/motoring/motoringvideo/8029374/Worlds-fastest-lawnmower-sets-new-record.html

 

Nice idea, but alas no!

[tommy gun 6]

are they kent cams by any chance?

[Mad Scientist 106]

Nope. They are a custom Piper grind, last seen living here:

 

http://forum.205gtidrivers.com/index.php?showtopic=89678&st=50

 

Can't wait!

 

[welshpug 1,657]

noice! so "should" be around the similar mark performance wise

[Mad Scientist 106]

It should certainly be getting up there, but it won't be quite as good power or torque wise. There's a few good reasons for this:

Intricacies in porting work

Different valve sizes

My exhaust manifold is more generic

I'm using a shorter rod

I'm using heavier pistons with bigger pin heights, therefore running more squish for safety

 

Should be an interesting comparisson though, since it will be mapped by Sandy on the same dyno. It will also mean an accurate, DIN corrected power and torque reading.

[PVFCpug 6]

It should certainly be getting up there, but it won't be quite as good power or torque wise. There's a few good reasons for this:

Intricacies in porting work

Different valve sizes

My exhaust manifold is more generic

I'm using a shorter rod

I'm using heavier pistons with bigger pin heights, therefore running more squish for safety

 

Should be an interesting comparisson though, since it will be mapped by Sandy on the same dyno. It will also mean an accurate, DIN corrected power and torque reading.

 

Bah, none of your rolling roads for you eh!!!!!

[Mad Scientist 106]

Not after last time! Still smarts to think about it now!!!

[Mad Scientist 106]

It should certainly be getting up there, but it won't be quite as good power or torque wise. There's a few good reasons for this:

Intricacies in porting work

Different valve sizes

My exhaust manifold is more generic

I'm using a shorter rod

I'm using heavier pistons with bigger pin heights, therefore running more squish for safety

 

Should be an interesting comparisson though, since it will be mapped by Sandy on the same dyno. It will also mean an accurate, DIN corrected power and torque reading.

 

Forgot about DJ's lighter flywheel and smaller, ligther clutch too.

[Sandy 191]

Clutch/flywheel won't affect power.

[Mad Scientist 106]

UPDATE:

 

I received a parcel from Colin this morning, containing my new inlet manifold and trumpets, along with the weld in brace. All made absolutely perfectly as usual. Unfortunately, the manifold needs a bit of a skim to make it angle down more, otherwise ill struggle to get a filter in and close the bonnet. Can't blame the fabrication for this, it just highlights that not all shells are identical. It was made from a jig that Colin has used before. Didn't matter, since I just sent it back down to Cornwall with my head!

 

New manifold, Jenvey 48's and new trumpets, alongside the strutbrace:

 

 

Bodies from above:

 

 

Bring the noise!:

 

 

 

I'm considering having the maifold crackle black coated to match the bodies, for no other reason than I am a tart.

 

 

[stu8v 68 1 Cars]

Looks real nice.

[marksorrento205 80]

Looking good Pedro!!