6.0L Stroker Discussion

Happy Monday. Looking for input and collaboration here. I’ve been throwing around ideas on how to increase the displacement of the 5.7L and keep it on the reasonable end of the price spectrum. One long utilized old school method is to offset grind the crankshaft rod journals to increase the stroke. The 3UR already has a 102mm stroke with 56mm rod journals. By offset grinding the journals to 53mm, the crank throw will increase by 3mm, stroke by 6mm, to give a new total of 108mm. The new displacement will be 5995cc. A light over bore to 94.25mm will give 6027cc.

When stroking an engine, either the connecting rods need to change in length, or the pin height in the piston needs to shrink by the same amount of the throw increase. The 3UR piston design can accommodate this, there is room. Either way, new rods and pistons will be required. Finding something off the shelf that can be modified to fit is the next step here, so I’ll start looking around. Static compression will need to be determined and adjusted for.

Problems. Will the crankshaft remain stiff enough? Stroking a crank in this manner reduces crank pin overlap, which is a big part of how stiff the crank structure is. For a normally aspirated build, I suspect we are well within range here. For forced induction, well, that’s the biggy. I’m not going to spin my TVS1900 to the limit… the beast has plenty up top for this work truck, simply after even stronger low end torque. Not at the expense of crankshaft longevity.

A little to start off with. 5.7 vs 5.0 rod journals. The 5.0 is the perfect source for the undersized rod bearings as they have the same 17mm width. Main bearings are the same size.

 

Have you looked at the stroker kits on the market? Fuzzy on this but I think a 6.0 kit is available.

 

I've also been kicking the idea of a 6.8 stroker but don't love the fact we need to sleeve the block but from the conversations I've had with XAT its not a problem.

https://www.briancrower.com/makes/toyota/3urfe_stroker.shtml

 

There are kits, but they are $$$$. $4 - $5k for the crankshaft alone. Of course $5k is cheap if a stock modded stroker crank is too wobbly and takes the engine out… at this point there’s just not a ton of value in the billet crank for this project.

As for sleeves, machining down into the main webs of an aluminum block just doesn’t sit well with me, either. It may be strong enough to handle 1000 hp, but what does it do to the fatigue life of the block in those areas?

 

Hey Brian, I see you're still into tinkering with 3URs. I like your idea, we have a lot of boosted trucks here that eventually build their blocks before or after they throw a rod. I have a few friends who could help you out testing it. I even think some have already as I've seen naturally aspirated Land Cruisers that pull almost as hard as a supercharged one.

 

@BRX nice to see you still around.

 

it's threads like this that cost me $.

 

Not my thread so my apologies up front.

Spraynard thinks the hidden power reserve of the 5.7 lies in an increase to the rev limit. Tighter valve springs to prevent the followers from freeing themselves perhaps. I would choose Beta C wire. Renton Spring has experience winding coils out of Beta.

 

Wondering on these built motors with a good cam in there if the motor would require its own ECU?

 

@BRX Great to see you here. If folks out your way have done such a thing, and are willing to share results, that will be excellent.

There is definitely tons of high end scream in the 3UR. Just look to the 5.0L 2UR and the results that were obtained by Yamaha when building it into the higher performing F car engine.

I’m not sure how far the stock ECU can take us. Abdulla likely knows.

 

@Jowett there was a forged build back in 2014 where they ground the crank journals to fit chevy style forged rods.

 

@Mdl good info, TY. The Chevy rods were likely for 2.1” journals, our 53mm journals are 2.08”.

A little measuring of the 3UR block gives us a very nice 9.82”/249.5mm deck height. That’s a tall deck, and no surprise given the very large stock stroke. Stock rods are a lengthy 6.47”/164.5mm, quite long and certainly required to keep pistons/rings happy with such a big stroke.

 

It being an open deck design could use a block guard/saver. Are the cinders just sprayed lining. Nikasil? And be resprayed after boring? If going that route. Know they can be re-sleeved.

 

Block guards are possibly useful for big power and 1/4 miles, but my reading points to daily driver type installs having potential cooling issues and cylinder distortion. Open decks have less support but they cool the cylinders quite nicely.

No spray lining/Nikasil, UR engines have cast in place iron liners. They are quite thin, so over boring needs to be very conservative.

 

Thanks! I was trying to remember from the lextreme tear down where he first did the 6.0 back in 2010 or so. Good to know.

 

Looks like I was mistaken the 6.0 stroker is no longer made by Lexstreme.
https://youtu.be/Mq-Pe3o7tJg?si=HLDXDdAp6bG2C7Nh


Recommend jumping to 7.0 stoker
https://www.tundras.com/threads/7-0l-stroker-kit.23033/

 

So what will be cheaper built block or sleeved stock block?

 

Not sure. I think fast lanes setup would be more cost effective than a 6.8.

 

It appears Lextreme did build the 6.0l using an offset ground crankshaft. There are pictures on his webpage of the looong connecting rods and forged pistons with pin moved up into the oil ring land. So it has been done, how it held up is the question.

 

and I’d be curious on the power ability. No replacement for displacement. But the ability to up the boost would be nice

 

More cc is more cc, power will rise, unless the crankshaft flexes too much.

 

Possibly so, yes.

I believe I've seen other vendors sell pistons and rods separate from the block.

Sorry don't want to distract from the purpose of this thread.

 

A built LS motor.



I’ll see myself out.

 

The highest revving 3UR out there revs higher than the 2nd gen 2URs at about 7500 RPM. It's also the most over built engine with +35 psi making 1500whp.

My initial plan with my 3UR swapped GT86 was to supercharge it, but that thing is more than a handful NA I can barely even floor it not to mention the limited space. I'm now looking into a high revving build at around the same 7500 RPM range and maybe I can squeeze a few cc out of it at the same time while the engine is out by grinding the journals. Other upgrades will include a full head upgrade with cams, springs, valves and porting. With a high compression piston and beefier rods, I might be able to get 500 at the crank without any boost.

I'm using Haltech on all my builds, but not due to the lack of tuneability of the stock ECU. It's mostly for adding additional accessories, parameters and features that a stock ECU will never be able to offer. For a mostly stock Tundra with just a built engine and a supercharger, HP tuners offers a great amount of tuneability with great results. I was able to tune a supercharged tundra from scratch within a couple of hours. Taking boost out of the equation, a few additional cc and a high flowing head shouldn't need a lot of adjustment in the tune.

 

forewarned - I'm going to oversimplify this question...here goes:


could it be as a simple as getting a 7.0L long block and dropping it into my truck...put all my shit back on it...tune it...and it will be awesome?

and it will run as smooth and "reliable" as my 5.7?


last request - answer as if you are speaking to a toddler or a Labrador Retriever.

 

Essentially yes

 

@BRX good info. I may have to pick your brain in the future concerning the Haltech. @snivilous and I were briefly discussing development of a timing cover that will allow all the goodies from a 2UR-GSE to be installed on the 3UR block… that could produce a very healthy running V8. The Yamaha heads, the DI, the oil scavenge pump for those heads…. Yummy!

@nobodyintexas Will it be a beast, probably. Reliability means different things to different people. Again, not a fan of sleeving an engine that wasn’t already built with them. Happy to be proven wrong on that.

 

We’ll be dealing with rod ratio… Great to the point article on rod ratio.

http://victorylibrary.com/mopar/rod-tech-c.htm

 

That would be a dream come true! One thing I would like to avoid if possible is the DI. At the current development stage of standalone ECUs, it would be a nightmare to tune Toyotas DI unless someone has already figured it out or maybe override the DI control box. Even then, the benefits might still not be worth the hassle. DI is great for fuel economy and squeezing a bit more power NA, but port injection can take you a long way power wise with enough boost.

Another thing you would need is a custom intake manifold, not sure if an adapter for the 2UR manifold would be the best idea.

 

I wonder what the 2022 and older Dakar T1 Hilux trucks use for an ECU? We could easily block off the DI, but it would be nice to keep it if possible. More boost and more compression w/o race fuel. Heck, the Tacoma I’m building has the stock 11.8:1 pistons and will easily take 8psi+ on premium.