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magn1t
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Re: Bored and stroked and destroked

Sat 25 Nov, 2017 8:21 pm

Freshly bored and honed 6G74 block, bored from 93 mm to 95 mm to take the 6G75 pistons.

Image
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....
4 intercoolers!!!!!!!!
Beat that!!!!
 
magn1t
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Re: Bored and stroked and destroked

Tue 12 Dec, 2017 10:17 pm

From that I can confirm that the 6G74 and 6G75 blocks are the same deck height.
I've had the same crank, rods and pistons dummied up in both blocks.
I don't have the correct bearings yet so it's been dummied up with old ones of the wrong size so there's a bit of slop in everything.
At TDC the 6G75 piston sits flush with the deck or possibly 1 mm down.I need bearings first, they're on the way.
Then I can turn back a couple of pages to try to figure out the CR using the measurements there.
I might even do a bit of grinding on the spacer plate too , maybe a 45 deg angle so it's bigger on the bore side than the head side?
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....
4 intercoolers!!!!!!!!
Beat that!!!!
 
magn1t
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Re: Bored and stroked and destroked

Sat 20 Jan, 2018 8:41 pm

For the 6G74 stroker, I've now got main bearings and big end bearings.
 
At TDC the 6G75 piston is 2 mm down the bore and at BDC it's 93 mm down the bore.That confirms a 91 mm stroke.

Need to work out the various possible CRs.
95 mm by 91 mm gives a swept volume of  645.111 cc (3870 cc)

Going back to about post no 53 for some numbers. 

Head vol 46 cc
thick head gasket (1.4 mm)  10 cc
Space , 2 mm, above piston at TDC 14 cc
Total chamber 70 cc
CR = 645 + 70  /   70     =       10.2
Which is a bit high unless you're on E85 or methanol.

So that's what the 3 mm spacer is for.
I don't think I've actually checked the hole size yet but lets assume 93 mm for now. About 20 cc.
Also add an extra head gasket, a thin one, 2 cc.

This time.........for CR
Head, 46 cc
thick gasket, 10 cc
Thin gasket, 3.5 cc
Spacer 21 cc
Space above piston 14 cc
Total, 80 cc
CR = 645 + 94.5 / 94.5 =    7.8   which is pretty much what I'd like.

(BTW I re did it due to getting the maths a bit out.)

Having a 95 mm bore and 93 mm spacer plate  2 mm above the piston  at TDC will give a bit of a squish band all the way around which is hopefully better than having a 95 mm spacer.

Got a few sets of bearings to use up.

Image

Piston at TDC. Still no rings.




Image


Bottom side.
Image
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....
4 intercoolers!!!!!!!!
Beat that!!!!
 
magn1t
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Re: Bored and stroked and destroked

Thu 16 Aug, 2018 7:10 pm

My camera died,the memory card for it did.......128K SD,  my cellphone died at the same time, the sim card died. lost all my contacts, not long after my eftpos car stopped working, had to go to bank.
My next pair of mivec heads are in the workshop getting tricked up, got a pro on the job , fancy angles on the seats , take off casting marks etc. reassemble with new seals.......but no pics, got a free replacement camera off the new boss man....no charger yet.
Making progress anyway.
That'll nearly complete the 6G7.forged stroker.
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....
4 intercoolers!!!!!!!!
Beat that!!!!
 
magn1t
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Re: Bored and stroked and destroked

Tue 13 Nov, 2018 11:02 pm

It's been a year since I've done anything to it.That means I've spent a grand total of ZERO on it.
My camera is sorted, upgraded phone, got money in bank.

Still chasing rings, someone's doing it for me. Seems like we need to go through Mitsubishi?, that's for 6G75s.
The heads (that's the mivec ones for the 72/74, I told him no hurry?
I think the oil squirters (for the 74 block) are here.

The good news, got another job a while back, closer to home (the last one ran out of funding) it's a growing business (es), I'm now in the recycling business as an Alchemist so I turn sh** into gold. Computer boards are worth $10 per kilo as scrap for gold extraction, we did half a ton recently.........the crank grinding machine has been relocated there (just for me), we just bought a CNC milling machine too, it's really for cabinet making but should cut aluminium.Cabinets, they're for new arcade machines.........Spacies. We(me) fix the old ones (does anyone remember Tokyo wars or the indy 500 with the rear projection 39 inch screen, I've fixed them too). Not much else is really worth fixing these days besides washing machines and dryers I do them too.
I should have a shipping container delivered to home (thanks boss) next week, need safe space for what's coming next.Plus more storage space.
The first engine to be finished and running will be my old Ford 351C, only because it doesn't need a computer wiring up for it (that's another story in its self because there's now enough bits for 2 1/2 of them, (no 2 is an offset ground stroker to go with chev rods, but that'll change),That's in the container.


The crank grinding machine is all set up and ready to go, It's got a 6G75 crank in it right now, the setup adjustments are all redone, I probably won't have time to do anything until shutdown over Christmas. 
Take note that this crank doesn't have balls in it like the 72 and 74 cranks. There was a thread on a forum recently( https://www.3sgto.org/threads/17202-Why ... crankshaft) about balls. NO you don't take them out, it's the worst possible thing to do to it.all you'll achieve is a fecked crank, leave them alone, if the crud inside won't come out then it won't come out and won't do any harm.

Image


We going to put Wainui on the map.


Next day edit........so I thought I'd better go check out what's happening.
I've got the heads back......all done at no charge. Can't get any better than that.
The rings.......It's because they're std size. Oversize is easy. Nearly impossible to get std size so still waiting.
The oil squirters....still coming.
So lets go back to the heads......Thanks Rob, thanks Hayden, I dropped them off to Customworks Naenae, Rob did them but did them in my son's workshop in his own time using the boy's (my) machines. the" Mira".....that's the fancy machine for doing seats.Looks like they've also been through the resurfacing machine....no it doesn't change the cam timing, not ever by any amount that you'll be able to measure....ever.

https://www.youtube.com/watch?v=IDtuXD-W9ZQ
That's just a google youtube showing what it is.....not our machine.For those who don't know.
Pics coming.

Image

Image


Image

Image

I asked for the casting marks to be cleaned up a bit but I really can't complain..............back to DIY. I've got 5 pairs of these heads. only enough bits to complete 4 sets, one set has been on the car 8 years now, so 3 spare sets to make 3 more mivec engines.  
Nearly forgot...new stem seals....so when I fire it up it won't smoke....because new stem seals fix all smoking problems.
Those spring retainers, they're factory titanium ones.......Aftermarket price? (about $500) They fit the normal DOHC heads too.

Fri night edit....my 6G75 rings have now turned up.....yay.
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....
4 intercoolers!!!!!!!!
Beat that!!!!
 
magn1t
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Re: Bored and stroked and destroked

Tue 20 Nov, 2018 9:36 pm

Another problem still not solved is the cam gear covers, not a big deal, sticky tape will fix it.
Image

That's the 6G72 with spacers and mivec heads, the lower cover is GTO, the upper covers are 30M Diamante. They overlap so it's easy and bits need cutting away.It would be good to make some proper ones though.Still haven't fitted the re conned heads yet.

This is a bit harder.
Image

This is the 6G74 Pajero block with all the GTO brackets modded to fit,2nd gen TT sump, 15G turbos,  decompression plates and 2nd gen N/A heads.
There's gaps that need filling.
I've thought about all sorts of ways of making new ones.....over about 10 years.
There's casting, printing and carving........from plastic or aluminium.Or even fibreglass or carbon fibre.
ABS plastic seems to be the best material...the factory way.
ABS can be welded with hot air.
It's readily available for free.
Easy to recycle by granulation.
Easy to mold or machine.


Still thinking.
Can probably make one set  by welding the factory ones, use that to make a mold out of maybe plaster?, then cast something?
Or maybe just cast a big block of ABS and carve it out on the CNC machine at work?
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....
4 intercoolers!!!!!!!!
Beat that!!!!
 
magn1t
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Re: Bored and stroked and destroked

Wed 12 Dec, 2018 9:31 pm

Piston pins?

So when you want new ones you just jump online and order some from murica?
What do you think you'll get?
Maybe
https://www.3sx.com/piston-pins-wrist-p ... gt-stealth
 
....the best?...wall thickness .200 inch or .220 inch....that's 5.08 mm or 5.5 mm.


They're all the same only completely different. 6 of them below but I've got more.
OK well a couple of years back I took some quick measurements  then decided that I had to pull apart a previously assembled block to throw out the pins.That was the wisecos. 
I fitted OEM ones in their place. Image


Image

From L to R there's the......
 6G75 pin,.......................... 22 mm dia, 57.86 long, 4.13 mm wall at ends, 4.7 mm wall centre.
6G74  SOHC Diamante........22 mm dia, 63.89 mm long, 5.08 mm wall ends, thicker at centre(can't measure).
6G72TT..............................22 mm dia, 62.72 mm long, 5.05 mm wall, thicker at centre.
Forged no 1........................22 mm dia, 63.51 mm long, 3.87 mm wall, right through.
Forged no 2.........................22 mm dia, 63.40 long, 4.04 mm wall, right through.
Forged no 3.......................22 mm dia, 63.45 long, 3.87 mm wall, right through. marked as 3C-21C JE.(it's a pin from a JE piston)
So forged no 1 and no 2 are Ross and Wisco, don't know which is which.


But what does it all mean?Stock 72 pistons are press fit pins, forged are held in with circlips or similar, 74 and 75 pins are held in with circlips.
So lets look at a 6G75.
If you try to use a 6G72 pin, it won't fit........it's too long.........thickest and heaviest and probably the strongest?
Needs shortening.

On the other hand my 72 stroker I assembled with stock pins and JE pistons (I think?), there might be too much end float on the pins now?
Remove JE pin at 63.45 mm long, fit stock pin at 62.72 mm long........only a half mm, probably doesn't matter?


As for the ones you pay top dollar for........unfit for purpose.


Image

Murican made rings for a Japper....how silly.I hope the gaps are right.
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....
4 intercoolers!!!!!!!!
Beat that!!!!
 
magn1t
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Re: Bored and stroked and destroked

Tue 01 Jan, 2019 11:13 pm

I started on the 6G75 crank, that's option no 3. I put a vid on ewetube. We've moved the machine, about 3 tons of it from wingate to wainuiomata,it's at my work so can play on it whenever I want to, just needs motivation. It's the first time used in nearly a year, been too busy.I got cut a bit short cos it stopped working, got more machine maintenance to do, it might be just a belt that needs loosening a bit?....But it might need a new motor.

https://www.youtube.com/watch?v=YAQO8ck5LiQ


But anyway, got a bit of a plan here, the no 1 , the 72/74, still got to fit the rebuilt heads.
The no 2, the 74 block stroked, still waiting on some parts.
In the meantime I stroke the 6G75 crank to 95 mm, dummy assemble it with the RB30 rods I've already got and modified.That's in the stock bore 75 block with the 75 pistons before I use those in the 74 block, make sure it all goes around, and around and not clunk.Then I can look into 97 mm holden pistons and bore the block....Maybe?

Got new turbos coming too, 2 of them ,.......big ones, maybe too big?.....but cheap.

a bit like here.

https://www.trademe.co.nz/motors/car-pa ... 684830.htm

Maybe use them to turbo the turbos.
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....
4 intercoolers!!!!!!!!
Beat that!!!!
 
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Re: Bored and stroked and destroked

Wed 02 Jan, 2019 5:35 pm

You're right, they are big turbos.

I love the comment on your youtube video:
Image
Image
 
magn1t
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Re: Bored and stroked and destroked

Wed 02 Jan, 2019 6:40 pm

Yes, I had a laugh at that.
I've now got the no 1 down to nearly final size, no 6 too, taken the crank out, brought home for some dummy assembly / testing.

The 6G74 stroker, just double checked, there was no cutting of counterweights to do for clearancing, the 6G75 there IS.

A 6G75 crank weighs in at 20.1 Kg
A 6G74 crank weighs in at 19.5 Kg
A 2nd gen 6G72 16.9
A 1st gen 6G72 roughly 15Kg.
edit 

Then I spent about 6 hours on it today and didn't get far enough.

Image

Image

The conrods, I modified them a couple of years back and test fitted them on the last crank I did. I've had to recut the stone to get the correct radius, was too big, the rod wouldn't fit.Then the counterweight was too big, still too big but just in the one spot. Easy to take down without moving the setup position.


The 60 deg v6 crank is the most time consuming one to do any sort of rework with.
Why?
With a 4 cylinder, there's only 3 setup positions, mains, big ends 1 and 4, big ends 2 and 3.
With a straight 6 there's 4 positions, mains, 1 and 6, 2 and 5, 3 and 4.
A V8 has 5, mains then one for each of the paired throws.
The 60 deg v6 has a different setup for each crank throw so 7 in total.
Like a V8 the cylinders at opposite ends are at different angles.
Unlike an I4 or I6 where they're at the same angle making initial setup a lot easier 'cos you can adjust both ends at the same time without having to move the crank and set it up again.
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....
4 intercoolers!!!!!!!!
Beat that!!!!
 
magn1t
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Re: Bored and stroked and destroked

Mon 07 Jan, 2019 10:56 pm

What turbos for a 4.2?
$599 on trademe....each.

I think I read on an evo forum that someone made 950Hp with 4G63 and one of these?
Must be slightly inflated numbers. I'd think about 750 each?

Image

Single T72 turbo upgrade anyone?
No, it's only for those who can't afford the second one.


So anyway....what's the specs on these things?
Comp housing A/R .80
Comp wheel, 76 mm / 102 mm
Turbine A/R .96.................A is area at the inlet, R is radius of the wheel.
Turbine wheel 64 mm / 74 mm

No such thing as A/R, it's actually A times R to make any sense.
Think on that?
For real sizes, I'll pull apart and measure, they'll be wrong?

(edit, easy to pull apart, I've measured and the numbers are correct.....surprise?)
From those numbers you'd expect it to have a compressor flow map a bit like a GT42- 53 trim as on stealth 316 ...,turbo upgrade.
All of the engine demand lines on that page are wrong too (surprise) due to the incorrect VE assumptions and also due to corrections made for high altitude of Arizona or wherever the author lives.
TT heads have low VE, mivec heads can have 130% or more VE in N/A form.....therefore make more power.


Ok,so these cranks I'm doing are going to break?
Of course they will, just got to find the limit.
Did I just read that someone just broke a billet one at 1K HP?
Well that's it for them then?
I've just got to do better?
Try reading 45 pages of 6G big boy builds?
They must have all blown up, it's gone too quiet.
Now diary of 1100 Hp, it's like fishermen....it got bigger.
Last edited by magn1t on Sat 12 Jan, 2019 3:45 pm, edited 3 times in total.
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....
4 intercoolers!!!!!!!!
Beat that!!!!
 
magn1t
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Re: Bored and stroked and destroked

Sat 12 Jan, 2019 1:53 am

Google, got to love it.

Where does all the info come from???

try 4.2 litre mitsubishi and mivec?


What comes up?




Flock of sheep?
Open minds?
Closed minds?
Followers?
Muricans?
The wall...???????
The ladder???

Well whatever ...but I've now seen pics of broken billet cranks?.;............Give me all of you money???
So was it because the oil holes were drilled all wrong or was it for  some other reason or is it just all wrong......or something else?

So if a billet crank breaks at 1100 HP? is it the crank or the tune?...well no. too much timing on E85 always bends rods.......Fecks everything else too.



OK so are aftermarket parts better than stock parts or not?
Are they made from better materials?
Can you prove it?
What loading do they fail at compared to stock?
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....
4 intercoolers!!!!!!!!
Beat that!!!!
 
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Re: Bored and stroked and destroked

Sat 12 Jan, 2019 8:17 pm

Speaking of E85, I've sent you a PM
Image
 
magn1t
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Re: Bored and stroked and destroked

Sat 12 Jan, 2019 9:08 pm

More pics.
Image

Image
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....
4 intercoolers!!!!!!!!
Beat that!!!!
 
magn1t
Topic Author
Posts: 2883
Joined: Mon 04 Feb, 2008 1:15 pm
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Re: Bored and stroked and destroked

Sun 20 Jan, 2019 12:15 am

What injectors for a stock computer and a bigger engine?
The 3.9 which is earmarked for my tow car which is currently resting with all the other broken GTOs.
It's not broken just not legal and a bit bruised.

Image

Got 10 440s off TM for about $150.
Got to flow test them....easy......viewtopic.php?f=9&t=4347 take the closest 6. Maybe try to high flow the leftovers for the water injection?


What happens with a bigger engine, stock ECU and injectors????

Take one load / RPM point....3500 RPM and no boost as in N/A and full throttle?.
For the same load (no, not load, throttle position)  the bigger engine will suck more air, gives a higher AFM Hz reading, (load is Airflow Hz/RPM) a corresponding higher IDC, more load (more Hz) should mean less timing which is better than more timing.
Going back a long time to cheap simple mods, one of the originals was to remove the side screens from the AFM in order to increase the bypass and give a lower output signal (lower Hz) .The drawback there was it would run lean, the o2 sensor picks it up and increases the fuel trims to correct the AFR . IDC increases so there's no gains unless the fuel trims are pegged out and it's still lean.
Combine the bigger engine with AFM mods.....and bigger injectors, what happens?
Going from say a 3.0 to a 3.9? that's 30%.
So 370 cc to ??...480 cc would be good.

The bigger engine will suck more air but won't read it all with modded AFM. If the two factors cancel then the load won't change. That should keep the timing pretty much as it should do? The extra unmetered air can be taken care of by the bigger injectors so long as the % changes are the same.
Stock injectors are good for 400 or so horses, 440s should give close to 500, the WI over the top will add a bit more depending on what's in the tank.

If the cheap / free mods don't work well enough, I've still got a 6A13TT ECU and adaptor cables, that's the budget programmable option. The knock control on links as well as most other aftermarket ecus doesn't work so it's never an option when running on pump fuel.
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....
4 intercoolers!!!!!!!!
Beat that!!!!
 
BATOOH
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Re: Bored and stroked and destroked

Mon 21 Jan, 2019 6:09 am

Have you got this right? You're effectively saying the stock ECU will drive stock injectors on a 3.9L engine. And your math says the upsized injectors need to be about 480cc. So by putting 440's in you are effectively undersizing the injectors. then to add to the discrepancy you are going to blow it with those bloody great big turbo's or are you thinking you will just run 9b's?

For my clarity's sake I thought stock injectors were 360 not 370 and the blue are normally called 450's and the yellows are 510 and the brown are 550's/560's..?

I run the 450's with stock ECU and 15b's and thats the fastest setup I've had on the race car. My road car has 510's and that thing used to fly but has taken a backseat to the race car ie take the EBC out and donate to the race car!...etc.

If you are aiming for 20 psi on the 3.9L engine I'd be putting in a minimum of 510's in it. I really like the 510's - from experience. 

I'm not wanting to argue, just think about your logic here... like for like it is, but 510's or bigger may be better dependant upon boost level.
 
magn1t
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Re: Bored and stroked and destroked

Mon 21 Jan, 2019 3:30 pm

Ok one step at a time. My tow car, the red one, it currently has stock pump but rewired so it's still 2 speed (fuel pressure is always perfect), stock injectors, 13G turbos and at about 12 pounds boost runs spot on without detonation or fuel cut. It's done a 12.8 / 106 1/4 mile like that years ago and done about 8.4 in the 1/8 mile
Those monster turbos, they're for the 4.2 in another car, they won't fit a GTO, not without sticking out the top.I might end up running 2 banks of injectors with that, undecided for now.
So keeping it simple ish, the 3.9 goes into the tow car, I replace the 13Gs with 15Gs which I've had sitting for a few years.The 15Gs have slightly bigger turbines.
Need some sort of injector upgrade without going all silly with computers. It's tuned to run on 95 RON now and should still be able to run just under 15 pounds with 15Gs and no knock with the right injectors. 
Ideally I'd also need to fit a Walbro 255 pump that I've already got, can't do that without adding an extra FPR, again from that link I made on fuel systems the fuel pressure at idle always increases due to outflow of the original FPR. That always messes with the tune unless you fix it first........tee the in and out fuel lines, one FPR on one fuel rail, one FPR on the other fuel rail.
Power output is always limited by the fuel choice, not the computer and not anything else. Aftermarket computers do nothing except make a hole in the pocket and cause blown engines when you eventually discover that the knock detection doesn't and never will work properly.

Blue top injectors....440 or 450....depends on google.
Stock ones??. 360 or 370?
That's why you flow test them.
It's what they actually flow with what fluid that's important.
From my link on flow testing, different fluids flow different volumes, petrol is the only fluid which flows the correct volume. You don't use petrol for flow testing for various reasons. E85 flows a different volume from petrol. It also has a different SG which means the mass flow is also different.....so if for example you were wanting to use E85, you need about 50% more mass flow not the internet commonly stated 30% (that comes from the calorific values of the 2 fuels), that's about 40 or so % more volume flow..........just to over complicate things when you think it's all easy.

Back to petrol.......If you were going from a 3.0 to a 3.5. that's about 16% or 17%...........420 cc would be about right.
Going to 3.9, 440 or 450 is a bit small BUT the factory mapping is always too rich at increased boost , that should lean it out a bit and give more power at the risk of getting knock.....but I've got water injection too.That prevents knock, if it works right and messing with moonshine % in the water helps.


If you run a stock ECU with stock engine AND 440 / 450 injectors, it'll run too rich and lose power. The fuel trims will shift lean to compensate the error in AFR under closed loop, that also affects WOT running, ideally you need to add a % of air bypass to bring the fuel trims back to zero, that gives the same end result as adding an AFC which is a slight timing advance which is bad  but with a gen 1 with adjustable CAS you can retard the base timing to compensate to an extent. If you've got a 2nd gen engine then adding a 1st gen CAS is one of the best mods to do to it. It makes the timing adjustable.
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....
4 intercoolers!!!!!!!!
Beat that!!!!
 
magn1t
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Re: Bored and stroked and destroked

Thu 24 Jan, 2019 10:35 pm

OK back to the 6G72 / 74 mivec with forged bits.
I got the heads rebuilt and that's it so I'm trying to make a bit of progress with this.
Previously i've built the bottom end, trial fitted the top end to degree the cams and get it close ...ish to where it should be.
I've now removed those heads to try to think on what's forgotton. Dropped a bit of sh** down the bores of course but no different from any "real" engine.

Image

There's a thin shim HG glued to the block with RTV, the spacer plate glued to that with RTV too.It's been like that for over a year with a composite gasket loose over the top , the heads on that , not torqued up but not loose either. All excess RTV removed.
What I seem to have forgotten about is piston to valve clearance.It should be OK  but OK means nothing unless you can put a number to it.......so that's next. Something like plasticene on the piston tops, needs doing twice, once with the low cams, second with the high cams.
Another problem......the headbolts are now effectively shorter.
Not really a problem...Use ARP studs?
Well no, Stock should work OK for this but what about say a 6G75 with a 6 mm instead of a 3 mm spacer?I found some bolts that were a bit longer, not sure what from but maybe diesel and maybe mitsi? 12 point head though.
2 of the headbolts on the mivec heads are hard up against the end so there's only washer diameter to get a socket onto.That might be a problem....
More measuring to do. Not an OEM problem with internal hex....how big are the nuts on ARP studs?



Image

Google to the rescue.......
https://www.3sx.com/arp-head-studs-kit- ... h-207-4205
Only $439.95...that'll be $US too. 
No thanks.

But what size is the nut?
There's a PDF.....it doesn't say??

Well there you go, it's not the crap they tell you like 105 ft lbs....that's important. What's always the most important is what you don't get told.The nut and top  part will be imperial?, the dia and thread where it goes into the block can't be anything other than the original metric.......14 is 9/16, that'll be too small so maybe 5/8 or maybe 11/16?........how big is the washer?
That's easy, I can measure it......22 ish mm.
My sidchrome 5/8 socket is 23.25 mm
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....
4 intercoolers!!!!!!!!
Beat that!!!!
 
BATOOH
Posts: 893
Joined: Fri 01 Apr, 2011 8:23 pm

Re: Bored and stroked and destroked

Fri 25 Jan, 2019 6:18 am

At 105 ft lbs should be akin to torqueing down a triple "Club Sandwich". I guess you're alluding to grinding down the Sidchrome socket to fit. Been there done that many a time. Old man taught me these tricks and still have his tools to show what he did..
 
magn1t
Topic Author
Posts: 2883
Joined: Mon 04 Feb, 2008 1:15 pm
Location: Upsetting the ricers on youtube 1magnit

Re: Bored and stroked and destroked

Sun 12 May, 2019 10:27 pm

Time for a 3 month update.
No, haven't done much, spent most of summer painting a fence, not even mine and not even getting paid, Karate kid style.


This is just the 72 block, the 74 I've done nothing with and still haven't finished the crank for the 75 block. The crank grinding machine is still at my work but had to move it a few feet which means I can't plug it in so it won't go. The answer to that is ridiculously simple but we won't go there for now.

Image

That mark that's left there, that's the one and only reason why you resurface the heads, it's corrosion and it's porous......you can't resurface a bent head as it's bent and the cams won't work.
It affects cam timing?
No it doesn't, it's immeasurable as far as timing goes.
Same reason you resurface the block....corrosion. A freshly machined surface won't leak.
But my block hasn't been resurfaced., it doesn't need it. there's no corrosion on the block, but I've seen first hand how a block looks before and after resurfacing, corrosion can be extremely hard to see and .(need to know what to look for)...like in the case of for example an XR6 turbo........if you do a HG job on it and it still leaks......hahahhaha, you forgot the block. do it again only properly.
OK so after 3 months I've done the club sandwitch thing, RTV, thin HG, more RTV, 3 mm spacer, more RTV, thick HG, more RTV, then the head.
I've done it in stages, sort of.......left off the last part with RTV, put the heads on, partially torqued to remove excess RTV. let it dry, remove heads, scrape off.......etc.no blocked holes.....they even line up, I think I read on the interweb somewhere tat they don't?

Image

I've even reused the shitty old composite headgaskets, can't do it without the RTV though.


Image
Because it takes so long, you look at it carefully,get dirt,  there's a mark just below the top of the bore, that's where the top ring gets to at TDC.

I've also fitted the lower plenum , gaskets and spacers. Done the same with the RTV, got to cobble up some sort of leak tester........'cos it'll leak?


I fitted the knock sensor too, it's so much easier before the heads go on.
But before that I had to use the signal generator and oscilloscope just to verify it's a good one and the right frequency output.

Image

I've torqued the head bolts 70 ft lbs, left for a few days, put paint marks on facing the front, backed off one on each side, retorqued to make sure paint marks end up where they started , as they do.Then I retorqued them all to 80, took note of how much extra angle it takes...because I can?...it'll come in handy later......80 ft lbs is enough.
Headlift?......what's that?....it doesn't exist....it's just more BS from murica.
The heads distort .......like blocks of rubber.....they distort and unseal between the bolts but only if you use the wrong heads to start with and then do really silly mods to them.....like grind away the divider between the intake ports............AND pay for it too..lol.

Image

I've got the belt fitted now, a bit unsure on the timing marks.
Image


I've already degreed the cams but with different heads. Because the seats have been recut and because the valves have been refaced, the tappet clearances will be a lot less, so got to start all over again, reset the clearances then check the open / close points and centrelines.

The cams and camtrays still need stripping and cleaning but that's the last job before they stay on for good.

There's the offset pulley on the right hand side for getting the rear bank adjusted, I've also got a bit of up / down adjustability in the water pump. That gives adjustment to the front bank. The bracket to the intake manifold doesn't fit but I can make it fit later on once it needs locking in place.

What about the solid tensioner?..I cobbled it together in about 15 minutes....what do  they cost at 3SX?...US 119.95???? ...you'd need a few brain cells missing to buy one?...but no....it's just for degreeing the cams. You'd never run a real engine with one?........or would you????
Not me.


Edit. this ewetoob is worth watching

https://www.youtube.com/watch?v=8iYfrUuXqdw


It's still a V6 but ally block, lots of similarities.........like the bore spacing is the same so a Nissan VR / VQ crank actually fits a mitsi 6G block, sort of......not that I'd expect anyone else to know?The main journals are 65 mm compared to the 74 at 64 mm and the 72 at 60 mm. The big end journals are 56 mm compared to the 74 crank at 55 mm and the 72 at 50 mm....so at least in theory I could rework one to fit a 74 block.....then it's just the flywheel, oil pump and front pulley to worry about.
Cranks crack and headgaskets leak.......old news. You'll often see a crack in a big end journal after it's spun a bearing but you won't see it until you clean it up by regrinding on the crank grinder machine. Likewise I've seen 2 broken cranks, both stock and diesels, one a Nissan the other a Mitsi.
 80 mm turbos like my new ones will make a gazillion PSI of boost....good to know.
That Andre fella, the same one that said to me some 15 years ago when looking at my TT heads at speedtech...........he said.......you wouldn't want to use those for a race engine.

So I haven't since.
Not that it matters but why do other people still do it?
When it's those same people will tell you how good a 4G63 downgrade is?????
Only because they can make the expected numbers with a 4G but can't with a 6G.
Must be rocket science?
Or maybe it's just that one of the definitions of insanity is doing the same thing over and over and expecting different results.
quote from barryboys.
Yes, yes, yes, that might be so, but you're clearly missing the bigger picture.....
4 intercoolers!!!!!!!!
Beat that!!!!

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