100rwkw out of a N/A 3TC. Is it possible for sub $1k?

[Silly Rabbit]

Just thought I would ask the question as my current fairly standard 3TC put out 80rwkws when last dyno'ed and I would like to see if an extra 20kws is achievable on that budget.

My current set up is a fresh rebuild of a hone, new rings and bearings, head all cleaned and valves seated but no head work, coupled with twin 40mm Solex carbs and Genie extractors. I also run a lightened and balanced clutch and flywheel. It has been a reliable and strong package for a few years now but would like to see 100rwkws from a NA 3TC

Does it come down to shaving the head to up the compression, putting in dual valve springs, new camshaft and that's it or am I going to be going all out on new parts, serious headwork, fully balanced bottom end, clutch lightened to the extreme??

My mate is a qualified mechanic and engine builder so labour on assembly is gonna be nix and he can do all the disassembly also. He is also handy with a die grinder so what are the benefits to be gained there?. I have read that the head design is pretty good for a stock unit so will i do more harm than good to play around with that side of things.

Yes it may be easier to do a blow through turbo setup or even run an SC14 but I have enjoyed the reliability of the NA and would like to keep it hopefully reliable (not that turbo and SC setups can't be but that comes with development and trial and error)

Any first hand experience or real world results would be greatly appreciated. Not interested in twin cam heads also as I have an abundance of 3T's and want to work with what I have already got.

Thanks,

[Tonyger]

Hi G,

Whats the expected power if you just have a basic set up with the sc14?

I've been told you can get 175hp out of a 3t as one of the guys from work has offered me it, I'm pretty sure its done quite a bit of engine work including head and bottom end. I can get you the specs if you need.

Thanks

[MRMOPARMAN]

the heads being similarish to chrysler Hemi's flow ok, but its difficult to get decent compression out of them, and if you do, you end up with massive dome top pistons which arent good for flame propergation. however they respond excellent to boost.

now if a turbo was part of the equation i would have said piece of piss. but big comp, big cams, multiple carbs/injection and shit adds up REAL quick. you would blow half your dosh on a cam, springs, and pushrods alone.

now if turbo, you would go TD04/TD05/T25g/T28/T03 (RB20) etc, J pipe, 350 blow through holley and E85.. done.

unless you find a heap of hot 2nd hand stuff, id say you will be pushing shit up hill, going N/A

[lexsmaz]

I don't know much about the 3TC motors, but as has been said it sounds very unlikely you are going to get there on your Budget, you will also have to No doubt increase the Rev limit & with some more aggressive cams you will lose a lot of the bottom end torque that you now have, you wont turbo it for that sort of money either but in my opinion its the best way to go & the bottom end torque doesn't suffer if you leave the compression ratio around what it like now

[king-szeitszam]

As others have said, there's absolutely no way you'll achieve a figure close to that for your budget N/A. The equipment involved to even start thinking about getting to those numbers is just too expensive- especially if you're thinking injection.
A high lift cam alone could set you back nearly a quarter of your total budget (thinking Wade Cams prices here).

The cheapest way I see this happening is a big f*** off cam fed by 45's DCOE's of your choosing, manifold port matched and head ported/polished, valves and springs done, lighten flywheel, high comp/OS pistons etc etc etc all the other shit.. you know this stuff already. But there's no way you'd do all that for $1000. BRD charges close that just for a set of O/S pistons and rods to match.


But then there's also the question of..why? You've already got one of the quicker stock 3TC's out there- why sacrifice the reliability and efficiency of a great build to potentially throw thousands at a setup that might well net you more headaches in the long run than its worth? Even with all that gear- you're still looking at a car that's going to be a pain in the arse to daily. Too aggressive a cam and your idle will be non-existent and all your power will be all top-end, too light a flywheel and your torque suffers and you fart along until your cam kicks in. Sure your peak power figures will be great but who roars around at 6000rpm all day?
Not to mention the reliability issues that always manage to spring up. Is a car like that really going to be enjoyable to drive?

If it were me I'd throw out any sort of elusive kw goal and just tastefully modify the internals within my budget. Keeping the setup you have and simply throwing a slightly more energetic cam in there that makes good power in the 2500-3000 range will yield some grin-inducing results by itself for around $300.
After that you can look at the other stuff like porting and polishing, lightening the flywheel within reason, increasing the displacement or even attaching a pair of Webers or something. All these things when approached with moderation and discretion will be cost effective ways of upgrading your vehicle without sacrificing the reliability and drivability of it at the same time.


Others might disagree, but hey I figure it's a 40 year old engine let's give it a bit of a break. It's an interesting question for sure and one of those "Why not?" things if it could be done to budget. Unfortunately I can't see that happening for the money and think that the cash would be much more satisfyingly spent without max power figures in mind. The whole exercise becomes less stressful then.
That said I'd love to see a 100kw 3TC and what kind of beast one would be with a no-budget build behind it, I daresay you could do more than 100kw...just planting the seed

[MRMOPARMAN]

go on, chuck a turbo on it. you know you want to, and will piss in 100rwkw!

[dumbass]

Sub 1k cash
Well u can't even buy a scent clutch for sub 1 k these days

[Silly Rabbit]

Thanks for all the responses guys. Really appreciate it.

I would have to agree that yeah it seems a far fetched goal and one that would come at possibly the expense of reliability and driveability. I reckon I will just see what I can do with the suggestions of cams / lightening of components etc for a fresh build and then see what it turns on the dyno. May only still pull 80-85kws but at least I will then be able to make the clear decision on a future turbo / SC build if I want to crack the ton.

Oh and I forgot to mention I work at Repco so cost on parts is minimal .

[MRMOPARMAN]

wiseco list high comp 3tc pistons in their catalogue (K508M87 for 87mm). would be a good start to getting it there.

oh and if going injection on the cheap, RB26 thottle bodies (maybe sr20 GTiR too?) are supposed to be so close to DCOE pattern its not funny.

[TheToyman75]

Silly Rabbit,

Your existing 3T-C makes damn good numbers so I suggest not touching that long motor one and doing the rebuild on a Stock 3T-C.

If you keen on doing the rebuild anyway it may as well be on a different engine. The stock rods are plenty strong enough and cast pistons will rev just fine too. Just get yourself the largest Standard overbore you can as an off the shelf Item. Endurotec do a 60 thou oversize and its list price is under $300 the set. Your bound to have a few options through your work.

http://precisionintl.com/engine.aspx?ID=1788&EID=4645

Combine them with a mild to medium cam so you don't need to shell out for the "race Spec" rocker gear or pushrods.
Deck the shit out of the block instead of the head while its getting bored and bump up the compression to 11:1 or so depending on how big the cam it and what sort of overlap it has. The "Bigger" the cam the lower your Dynamic compression may potentially be.

Port match the head to your exist twin carb manifold and headers and your away.

Stick your existing accessories on the new long motor and just see how it goes. Worse cast scenario it makes fuck all more power than you have now and you have a know good reliable 3T-C as a spare or sale able item.

Will it make 100 rwkw, probably not on your budget. But unless your getting the machining and balancing for close to free you wont build anything for $1000. Fuck, Balancing and boring alone will cost you around $1000.

With that said, a Stout 3T-C will make damn near as much as a stout 3T-G. They are both cross flow heads with similar combustion chambers and you already have the side drafts on it and the lightened flywheel.

For comparison and reflection.

Compression ratio / Power:

2T-C – 8.5:1 / 102 HP at 6000 rpm with a maximum torque of 14.0 m-kg (101 ft-lb) at 3800 rpm.
2T-B – 9.4:1 / 113 HP at 6000 rpm with a maximum torque of 15.1 m-kg (109 ft-lb) at 4200 rpm.
2T-G - 9.8:1 / 124 HP at 6400 rpm with a maximum torque of 15.6 m-kg (113 ft-lb) at 5200 rpm


So given the 2T-G had higher compression (And probably more valve lift but I don't know what ratio the 2T-B rocker arms are to work it out) than the 2T-B and the 2T-G only made 11 HP more, How much of that 11 HP do you really think was in the head design

[ctrain]

my 3tc turbo makes 110kw on 5psi with the stupid suck though setup, and i think it still spins the standard clutch when boost kicks in at full throttle.

3tc turbo is the ONLY way to go to get power, unless you send you credit card and engine to BRD racing haha!

[MorGo]

The stock head flow quite poorly considering it's a hemi design.In fact the head would be the limiting factor since it flows just enough to make some 135-140 hp.Proper seat/valve shapes go much higher and even moderate port job take it around 165-170 hp potential.Above that the physical dimensions come (the outside widht of the port is ~40 mm so 36 mm port is...)
Proper headwork,sidedraft carbs and some moderate cam are the order.

[king-szeitszam]

oh and if going injection on the cheap, RB26 thottle bodies (maybe sr20 GTiR too?) are supposed to be so close to DCOE pattern its not funny.

Wish I'd read this about 12 months ago, would have saved me a tonne.

[MRMOPARMAN]

Wish I'd read this about 12 months ago, would have saved me a tonne.

i really should pull my finger out and pull my throttle bodies off and confirm/deny that. i have both throttles and a DCOE manifold lying around dormant atm.

[Silly Rabbit]

Thanks for the input Cam, Callum and especially Rod. Pretty much confirms that a decent boost in compression and suitable cam is going to be in order. Then it comes down to putting it all together properly and seeing what happens. Seems like 100rwkws is out of reach when a turbo is only pulling 110 but can't hurt to try.