So, do you think 6a13TT can dive into 11s or even 10s?

[bradc]

might be an idea to convert to an LSD for this operation valmes

[Eurospec]

might be an idea to convert to an LSD for this operation valmes

I agree, i'm thinking clutch or ayc diff will blow.

The nitrous route will get you there, but its a good idea to think of the engine as dissposable if you are gonna fire in such a big shot.

We fired a 150 shot into our fto, NO traction, bouncing off the rev limiter faster than you could change gear and lifted the heads a little. Every single vac line blew off the engine! It worked, but it wasnt pretty. The head studs couldnt hold it and an awful lot of white smoke was generated as the coolant burnt off! Without NOS, the engine still runs fine after probably 5000 miles!

As for weight loss, bin the air con pump, the air con piping and rad, the reciever drier and all that crap. Removing interior isnt worth it, except for replacing the seats with race seats- although i think you might have done that already.

For the fuel system, well just the obvious, make sure your pump can flow enough at your max anticipated boost pressure to support the injectors at 100% and the NOS.

Good luck with it mate, i think you stand a good chance of doing it, and if it all goes wrong and you end up walking home, at least you are going to learn the limit of some component or other, which only helps for the next time.

Cheers,

Ben.

[valmes]

btw here are couple of videos from last year event (DragBitva2006):

http://youtube.com/watch?v=AM54qjQDgDk
http://blade.gallery.ru/videos/2139.html

[stuey]

Good luck dude, great video trailer of the event by the way...

[amsoil]

Rods

Arrows www.arrowsprecision.com 0044 1455 234200
Arias Forged Pistons 001 310 532 9737
Clarendon Engineering 01455 841200
Carillo 001 949 498 1800
Farndon Enineering 02476 366910
Oliver 001 616 451 833
Pankl 0043 3862 512 500
Cosworth 01604 752444


Bolts
ARP www.arp-bolts.com 001 1455 234200

Pistons
AE 01274 729 595
Arias 01274 729595
Cosworth 01604 752444
JE Pistons 001 714 898 9763
Omega 0121 559 6778
Ross www.coordsport.com 01384 216109

You will also need a billet or forged crank to EN40B spec so may as well look into boring as stroking (if possible) in the 1st instance as this will obviously increase the engines capacity and cubic inches are the easiest way to make power.

Get racecar engineering to find out the companies at the top of the pile for everything you need, you wont get better but the question really is if you really need the very best at a premium price?

Buying unwanted race race parts will save you a fortune if appropriate, Also reasearching if you can use other more common (and therefore more numerous and cheaper) parts inside your as yet custom made set of internals is also facinating; ie I use SBC Small block Chevy rods inside my Jag engines. Dollars are cheap, the lengths are the same and the smaller Big end looses weight from the crank journals (and allows a larger stroke from the same forging) and weight from the rod. I now hear that the latest racing chevy engines use Honda rods! for exactly the same reason I use chevy in the Jag. So maybe the next time I have the internals made , rather than luck in of someones elses parts at a fraction of the cost, I may consider Honda in the Jag; hope you get the idea.

Nearly forgot; your block WILL need steel caps if it hasn't got them as standard (not ally or cast iron) . If you really get serious it may also need a 'strap' .

[amsoil]

These are cheap , (but only if correct for your engine)
http://cgi.ebay.co.uk/Mitsubishi-300...QQcmdZViewItem
You get the idea

[Nutter_John]

wrong size don , our rods are a different lenght

there is toyota car that has a lenght closet to the 6a13 , it is slightly out but this would help reduce the compression ratio . I have attached a list of conrods there sizes and ( small end , big end , lenght , width etc )

[amsoil]

I thought they might be but the dealer is worth a phone call as its like free rods with a package like that. Other thoughts are that a smaller rod , end to end, will allow a longer stroke without the std piston sticking out the top. If you are getting a custom set of pistons then the wrist pin can be at moved up and down a little and the diameter bored and reamed to whatever size you want and the forging will allow. If the Big end size is smaller in the rod then the custom crank is made accordingly. Realistically the limits are what bearings are available and how far you can go without loosing the intergity of the block ; a little 'fettlin' inside the bolck is very common when upping the capacity.
Important is you get a 'package' and preferably that someone else has paid to develope and prove.

[bradc]

Don, you've seen pics of my engine disassembled, and you've seen the rods + pistons + crank on that. In your opinion for relaible 500hp running everyday I'm going to get new forged pistons and rods, but do you think the crank looks fine? I'm not going to go past 7000rpm, so is it really needed?

Also what are you talking about with the 'steel caps' and a strap comment, and how important are ARP head bolts? I never figured that one out....

[Nick Mann]

Having seen a 6A13 block stripped, I would say that there is an option for a bit of stroking. ( ) The smaller rod with a bigger offset on the crank could be a good way to go. Unfortunately, I don't have enough knowledge to say ho much more of the cylinder could be used. It appeared to me that there were several millimetres of available cylinder unused in the block I saw.

[zentac]

our thoughts exactly, I have a spare block that we are going to cut up to see just how far it can be bored.

[Nick Mann]

our thoughts exactly, I have a spare block that we are going to cut up to see just how far it can be bored.

Talk to Nobles, Richard. They started down that road for PJ. I'm not sure how far they got.

[bradc]

Why bore out though, isn't that going to weaken the block having the cylinders closer to each other?

[Eurospec]

Just on the bore out ability....

On the 6G72 its common for the head gasket to fail between the centre bore and the water jacket surrounding it. In high hp applications its even possible to melt away the edge of the combustion chamber at this point.

The 6A12 certainly has water jackets positioned in the same place, and the blocks being very very similar, i imagine the 6A13 does too.

If you overbore it, you will reduce the amount of material separating the jacket from the bore at this point, and therfore weaken the area.

A guy called Ray pampena who has built the worlds most powerfull 6g72 (put down over 900 at the wheels in an AUTO!) has done quite a bit of research into this phenominum and recons the thing to do is to weld supports into the water jacket at that point to prevent the flexing which allows the gasket to breach at that point.

Here is an example of an extreme failure

http://img.photobucket.com/albums/v379/benh/gtohead.jpg

Not saying this is going to happen if you go with an overbore, but in high boost high hp applications it is going to make it more likely.

Hope thats helpful,

Cheers,

Ben.

[amsoil]

Let it be clear that I don't know this particular engine which may very well have some quirks of its own. Steel main bearing caps (if not already on this engine, you tell me) are always needed on very uprated engine as cast caps split, usually from the shock of detonation and ally caps are usually only built for the standard application. Some engines are known to flex in high power applications such as the Rover/ Buick V8 which absolutely needs what is called a girdle or strap at the bottom end. This is something like an additional plate that connets all the main bearing caps together and not only prevents one from blowing off but stiffens up the bottom of the block keeping the crank running true.
With over boring you will need custom gaskets or better still Wills or Coopers rings. There sealing rings usually sit in a recess at the top of the bores and are for very good seal of the cylinders under extreme pressure They are pritty well a must and can even be reused a few times.
The only time I have seen 'burn through like the pics on that cylinder head is on drag racing cars running Nos and or Nitro; Its is nearly always solved by rewelding and is not so uncommon.
Just wondering if things would be easier to fit a 3L v6 as it a straight 20% increase in capacity as standard which will = 30+ % increase in available power , then do the mods to this as clearly the rods and pistons appear available? just asking.

[bradc]

Don, the 6A13 sits the other way to the 6G72 engines, so it's probably a bit difficult to convert to one of them. We could drop in the new short V8 that Volvo make for east-west engine bays, that would be fun

imho the 2.5l v6 is big enough for what 99% of us want to do, the stock turbos provide virtually instant boost and are good for 330hp, maybe a little bit more. It sounds as if boring is out of the question, so maybe stroking it slightly could be done.

[Eurospec]

Some interesting stuff in this thread!

Re flex, the 6G72, which is a lot beefier at the bottom than the 6A13 will bend a forged crank around the 900hp level. The most visible effect of this is that the two centre main bearings (as opposed to the big end shells) get scowled out by the crank. Keep going and the crank eventualy cracks and then breaks. The US guys are developing billet cranks now to help withstand this.

If you are building a powerful motor that needs to have reliability for every day use, then a forged crank will help. Balancing it as a rotational assembly will help too in terms of reducing the amplitude of any vibration and helping it if you intend to rev high or for longer periods. I was surprised just how much came off! Be sure to have the whole lot balanced though.

Steel con rods, like crower et al, will come with steel caps and strengthened bolts.

ARP head (and or bottom end) studs will help contain the flexing that occurs in the joints and you can of course tighten them more than std.

I dont know enough about the 6A13 to say when the nasty stuff will start to occur in terms of power output, but go high enough and the weak part will be found.

If you are building a monster engine i wouldnt grind the crank to a lower diameter and fit oversize shells. Even in a standard engine i have gone right off this. My reasoning being that you take a crank to an engineers and say, okay here is a crank, please take 10 thou off the journals, because you know you can get 10 thou over shells. They do. Firstly, this reduces the crank diameter, which for a monster engine certainly isnt going to stregthen it. 2nd, what are they taking 10 thou off? The high point? The low point? the manufactures spec? You never know unless your machine shop is very good. For quite a while we actually stopped getting cranks ground for exactly this reason when fixing failed bottom ends. Now we have found through one of our contacts a machine shop who take the crank and grind it. They then nitride it, which increases the size of the journals. They then polish it back to exactly the manufacturers spec. They also provide matched shells, mains and thrusts. For monster engines we go with new OEM forged cranks.

When increasing the capacity, say with a stroker crank, then as Don has suggested, there is quite a bit of work inside the block. The girdle which contains the mains may need 'clearancing' to stop the counter weights or the rod caps smacking it. For clearancing, read needs bits machined off it. This is going to mean that the bearing journals in this girdle and in the block need line honing to take out any deviation which may have occured as other bits were machined. You might need pistons with shorter skirts, or the wells in the bottom of the bores machined out a little.

Stroker kits are very young in the 72, and as yet no one has seen any issues which this machining work may throw up. It may be none, and certainly the initial results in the US have not thrown up any issues. there are stroker kits there for the 4G63 and i have heard of no issues with those, even in extremely high hp aplications.

Cheers,

Ben.

[amsoil]

Ok its starting to get good! Now are we saying that it is known that the Crank definately is forged as standard? Do all the big end bearing bottom 'caps' come off together as if the bottom of the engine is split ? or are they separate bearing caps? Quite important as it is possible that this engine might just be a very good basis for upping the power relatively cheaply. (well to the 5/600 mark anyway)

[calum]

If there's an issue with boring out and hitting the water jacket then liners can also be considered/ used.

I really don't think you're going to need a new crank for 550-650bhp, but I'm talking about 'normal' mods, not switching on a 150 NOS shot all of a sudden. I can imagine that loads it up FAST and may cause issues.

Calum

[Nutter_John]

Don we can show you a crank and ends caps tomorrow