Which 2TGEU crank for Full Race Motor

[idealneil]

Hey all, I am in the planning stages of building up a full house 2TGEU Race engine. I am looking to keep the engine around 1600cc, and the standard bore / stroke of the 2TGEU is reasonably good.

My concern lies with which crank to use. The standard 2TG crank isn't a full counterweight crank like the later 3TGTE cranks, and from what I've learnt / read. A full counterweight crank is more suited to high RPM sustained use? Any Comments on this???

What are peoples experiences with the standard 2TGEU crank at high RPMs? Or Does anyone have some advice on where to find a full counterweight 1600cc crank? Most of the builds I've read and seen, the engines have been upsized by the use of the 3TGTE crank making them 1800cc+.

I have sent Kameria an email to see if they do an 1600cc option crank, and even the older Novamotors were up in the capacity as well, so not sure what to expect there.

Any advice or direction on where to look would be greatly appreciated.

Thanks for your time.

Cheers Neil
[email protected]
Timaru, New Zealand

[king-szeitszam]

The first thing that comes to mind is rather than buying a $2000 crankshaft, you could just go to an engine/crankshaft balancer and have your existing one balanced.
I've never had it done myself, but I have a mate with a highly strung 4AGE that went down this road. I'm pretty sure he used Paul England- but don't quote me.

Dynamic Balancing | Paul England Engineering Melbourne

Maybe give them a ring and see if what they offer suits your needs. You'll probably have some reputable engine balancers in NZ that you can call too.

A couple NZ balancers off the top of my head:

Franklin Engineering
Franklin Engineering - Franklin balancing specialists
ATL Balancing
Home @ atlbalancing.co.nz

That said with the right cams, ARP bolts, HD valve springs etc etc 2TG's are known to be quite rev happy and will rev to 8500 and beyond with (as i understood) stock cranks.


Other than that my only recommendation woud be to look through the forums to see what other toymodders have done, there's more than a few very worked 2TG's on here that would serve as good guides for what you're planning to do.

Cheers

[Celica RA45]

the later efi 1s did go to a fully counter balanced crank and would be the pick of them .on rev range 8000 would be a safe rev limit ,over that wouldnt be 2 safe with the big valves ,big cams etc
try and use std inlet for carbies make a 100mm spacer and use use dcoe quads with injectors and short ram tubes .have most of the trd 18rg/2tg cam profiles as well and i would say kelfords would have them as well

[king-szeitszam]

Celica RA45- might have misread what you meant mate so sorry if that's the case. Do you mean ITB's? If so why the need for the spacer? 100mm would chew up a lot of room, and you'd start running out of space on the inlet side pretty quick. I'm assuming this is going into a 1st gen.
I found this out the hard way- running DCOE throttle bodies on the std twin carb manifold and having to buy shorter ram tubes as the original ones fouled the strut tower. Unless you manage to find 'short' (80mm or so) quad throttles it'll be difficult to have much in the way of spacers in there- especially considering that it's recommended you have 50mm of free air in front of the ram tubes to allow proper air flow- or so I'm told.

[idealneil]

Hey, thanks for the comments so far. Celica RA45 do you mean the 2TGEU engines that dont have the casting numbers on the heads. The 262 Head 2TGEU's? Would knife edging and shot peening the crank as well a full balance be the go? I've read alittle bit about offset grinding the crank to shorten the stroke abit more, and then bringing the bore out abit to get a bigger stroke / bore ratio. Any thoughts on this?

What kind of throttle bodies did you use on your engines? Are there any graphs or formulas for working out inlet tract lengths? As I know there is alot to be gained from having the right tract length.

Thanks for your help, Cheers Neil

BTW - The engine is going in my TE71 GT Hardtop, so should be enough room in the engine bay as I'm going to floor mount pedal box so won't have anything on the firewall.

[king-szeitszam]

262 was the last casting so I'd say it would have to be included in the variants that had balanced cranks.

I used 45mm DCOE pattern throttle bodies from a German company called Dbilas Dynamic- build quality is absolutely second to none and the throttle linkage is nothing short of a work of art. They're about 136mm long and I believe that Solex carbies are about 146mm long. I have the standard 2TG manifold and am using the original 15mm rubber/plastic spacers that came with the manifold between it and the throttles. I've strapped 75mm ram tubes on for better low down, you'll be looking at 30-50mm max for your application.

As for graphs, can't say I ever looked into it as it didn't really bother me. The power gain is quite large with the EFI throttles no matter how you put them on (as long as it's right), and my car is only a daily so I didn't care too much. Not to say that there wouldn't be benefit in going more in depth with it though.
As I understand it shorter is better with high RPM applications.
You will struggle to find a good throttle body set up shorter than 80mm. Dbilas Dynamic offer throttles in 80mm sizes which would probably be better suited to racing/high rpm applications like yours- almost all high-rpm throttle systems I have seen have had very short inlet tract lengths (Highly strung 4AGE's for example).

The problem when making short throttle bodies is making room for mounting the injectors. Looking at the 80mm types, there really isn't much room left to play with. I'd say anything smaller than that and the manufacturers would be running out of room for an injector boss and you'd be looking at having the injectors mounted in the head or doing the "I <3 backfires" system shooting straight down the throat.

I'm sure there are some guru's out there that will be able to shed some more light on it.

[AE25]

not sure what is allowed under the race rules for engine mods, but consider modern efi bike throttles if going quad throttle. they're compact and have injectors in the throttle bodies which makes manifold fab easier than say 20v throttles. downside is bike engines are usually pretty compact too so the throttles may need spacing apart for a straight runner intake.

[king-szeitszam]

not sure what is allowed under the race rules for engine mods, but consider modern efi bike throttles if going quad throttle. they're compact and have injectors in the throttle bodies which makes manifold fab easier than say 20v throttles. downside is bike engines are usually pretty compact too so the throttles may need spacing apart for a straight runner intake.

Another good option that I considered, only speed bump is that you'll need to make a nifty adapter plate to get them to play nice with the DCOE bolt pattern, and the spacing issue mentioned above. Also I'm not sure how ram tubes fit on motorbike throttles, I have absolutely zero knowledge on bike. The upside is that you could have ram tubes like 150mm long if you wanted for maximum low down power.
I couldn't be bothered with the fabrication involved but if you're more handy than I am bike throttles are probably the cheapest way to go.

[bmxer54]

casey has a few here http://www.toymods.org.au/forums/eng...-3t-parts.html
they seem to be the fully counterweighted ones you are looking for

Cheers,

Peter

[king-szeitszam]

casey has a few here http://www.toymods.org.au/forums/eng...-3t-parts.html
they seem to be the fully counterweighted ones you are looking for

Cheers,

Peter

Yep I'll vouch for Casey, bought some stuff off him recently. Probably not going to find a crank elsewhere for cheaper than what he's got them for (probably not going to find a crank elsewhere full stop).

[stidnam]

OP is in NZ so I doubt he'll buy a crank from Aus and ship it across. Should be able to get one cheap enough on trademe

[oldeskewltoy]

Have you asked a crankshaft maker how much a fully counter weighted custom crank would run? part of the reason for the 4AG's success is the crank is a counter weighted design, early ones are partial-full counter weights, while the later 4AG cranks are fully counter weighted.

I know it isn't cheap... but racing is never cheap... and a modern crank in the older TG might just make it interesting.....