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GC 2 LITER TC TWIN-CAM PREP FOR LADA

Posted: May 2nd, 2012, 4:00 pm
by Guy Croft
Documenting the build of a GC engine for Ian (badlyworntoy) whose fantastic car is featured in 'Readers' Cars'


GC

Re: GC 2 LITER TC TWIN-CAM PREP FOR LADA

Posted: May 2nd, 2012, 10:09 pm
by badlyworntoy
Thanks for publishing the build in this sort of format Guy, it makes understanding it all and referencing things far simpler without the need for all the finer detail. Its also the first time (I think) we've seen all the stages of just one particular engine catalogued rather than bits of several, its going to be very interesting to see how it develops over the next few weeks.
One point of confusion to note though....where the heck did you get the sunny day from?

Re: GC 2 LITER TC TWIN-CAM PREP FOR LADA

Posted: May 4th, 2012, 3:47 pm
by Guy Croft
Moving along..

Re: GC 2 LITER TC TWIN-CAM PREP FOR LADA

Posted: May 24th, 2012, 9:05 am
by Guy Croft
on with crankcase prep ..

GC

Re: GC 2 LITER TC TWIN-CAM PREP FOR LADA

Posted: May 25th, 2012, 3:17 am
by tmvolumex
Guy,
Great pics and text.
Very nice!
Now I see what that VX head I bought from you went through.
Tom

Re: GC 2 LITER TC TWIN-CAM PREP FOR LADA

Posted: May 25th, 2012, 9:54 am
by Urbancamo
Guy

Your meticulousness always amazes me! Thanks for sharing this kind of information, it's very satisfying to read & learn.

This really shows how much there is things to do when building a proper engine.

Re: GC 2 LITER TC TWIN-CAM PREP FOR LADA

Posted: June 1st, 2012, 9:51 am
by Guy Croft
moving along..

GC

Re: GC 2 LITER TC TWIN-CAM PREP FOR LADA

Posted: June 1st, 2012, 1:43 pm
by Guy Croft
contd...

GC

Re: GC 2 LITER TC TWIN-CAM PREP FOR LADA

Posted: June 15th, 2012, 9:38 am
by Guy Croft
mving along with the head prep for Guy Croft spec head....

the conversion to 43.5mm inlet valve with 36mm OE standard exhaust, plus porting and seat mods will give a head easily capable of 180bhp + and in this case with the IIID/IIIA combo on 44IDF likely be similar to Miroslaw's Polish Rally Gp4 replica in performance.

Guy Croft

Re: GC 2 LITER TC TWIN-CAM PREP FOR LADA

Posted: June 16th, 2012, 9:26 pm
by Biancorally
Hi Guy,

can you show us the hidden part of your work done during the installation of valve seat insert, with the Serdi? Thing that interests me enormously, never seen here before! Just a few picture, if possible, at opportunity.

Many thanks


Daniel

Re: GC 2 LITER TC TWIN-CAM PREP FOR LADA

Posted: July 12th, 2012, 3:42 pm
by Guy Croft
Whilst I did do that op for years and years using a milling machine it's done by one of our first tier suppliers. Don't have any photos but will try.

In the meantime GC.CP forged HC pistons are now here so on with the build..

GC

Re: GC 2 LITER TC TWIN-CAM PREP FOR LADA

Posted: July 12th, 2012, 3:45 pm
by Guy Croft
Here is the piston design data. If everyone went to these lengths (which they do not) forged piston manufacturers' lives would be a lot simpler and far fewer inappropriate-ups would occur...

GC

Re: GC 2 LITER TC TWIN-CAM PREP FOR LADA

Posted: July 29th, 2012, 12:39 pm
by Guy Croft
Building up the head with GC 3D/3A combo and 3VSR springs, OE turbo stem seals and race spring bases.

Re: GC 2 LITER TC TWIN-CAM PREP FOR LADA

Posted: May 1st, 2016, 4:39 pm
by Piotrek125p
GC, I don't want make a new thread so I decide to ask you here about one detail of this engine.

You done here a 43.5mm intake valve conversion, so why you decide to using a top hat shims ? I know that your valve-seat combo and stem heights are really detailed designed before you do this kind of op, are you took into account the change of the camshaft in the future ? It its a only reason for me why you decided to use a top hat shims if you can fit a valve seats with any height.

Why I asking about it now ? Because I will make a 43.5mm intake valve conversion in my II stage head and I want to make a valve seat with 30-45-70 degree only for your IIIA cam, I don't want in a future change this cam for any and I want to avoid using a top hat shims.

Re: GC 2 LITER TC TWIN-CAM PREP FOR LADA

Posted: May 1st, 2016, 6:37 pm
by Guy Croft
crikey, that post is TEN YEARS OLD!!

I had no idea the forum had been going so long.

As for top-hat shims it depends on the cams, finished valve seats and valves.

Grinding the seats to make the valves deeper is not always an acceptable solution - because I have to have a parallel lower throat region and 70 deg narrowing grind and if you grind the contact face too deep (eg 1 or 2mm deeper than standard to accommodate a small base circle like GC 3A or 3D/4A you will have no seat insert left at all.

Of course I can design new seat inserts that fit deeper than standard but I don't ever do that unless I need bigger diameter ones. And even then I avoid going too deep into the head, you have to be careful about the thickness of the casting..

And - very very important - the deeper the valve - the bigger the chamber, which is one very good reason why forged pistons should NEVER be ordered before the head prep is finished and the cc measured...

GC

GC