Bore/stroke and stroke/rod ratios

[Touge]

NA?

 

I'd like to see this motor, especially if it produces 142.5ft/lb/L of displacement.

 

Well my memory failed me. Larry's motor made 299hp and 189tq.

 

Scroll Down for the dyno slip

 

Here's the link to the build-up of the engine:

 

Link

[Gollum]

NA?

 

I'd like to see this motor, especially if it produces 142.5ft/lb/L of displacement.

 

Doesn't sound impossible... Unless he's running pump gas petrol on that dyno run... Then that's a little crazy.

 

The type R B series head has the capability to rev well into the 10k range and beyond. The key is to get it to breathe up there and then package the rest of it to match. Even right out of the box the type R keeps pull hard all the way to it's rev limit, and onces lifted doesn't start dropping in power until about 10,250, then I think you're reaching the limits of the stock valvetrain. (this is first hand experience btw, so don't ask for "magical internet references). I don't have any hard numbers for what I've seen on that engine configuration, but I can say that as far as RPM's go, those motors are wild.

[MAG58]

Torque is not RPM dependant. I charge you to find even F1 motors that come close to or break 100ft/lb per L. FWIW, at 18k, an F1 motor has to produce just shy of 230ftlbs to get to 750hp.

[Gollum]

Woops, sorry there bob, I was thinking we were talking about HP/Liter, guess that's what I get for posting too briskly.

 

He's making a bit shy of 100 fl/L, but his numbers certainly are impressive. Over 300hp on one dyno by 8400!!! And he IS running pump gas, on 13.4:1 compression!!!! Makes me wonder how much he might have on the table if he were to put some race gas in.

 

If you look through that link though, he certainly knows his stuff when it comes to honda heads. His attention to detail is definitely up there and certainly shows that there's no "magic bullet" but that it takes a painstaking level of detail to everything to put those kind of numbers down.

 

Overall, the fact he's making 150hp per liter by 8500rpm on pump gas is just astounding.

[Touge]

Doesn't sound impossible... Unless he's running pump gas petrol on that dyno run... Then that's a little crazy.

 

The type R B series head has the capability to rev well into the 10k range and beyond. The key is to get it to breathe up there and then package the rest of it to match. Even right out of the box the type R keeps pull hard all the way to it's rev limit, and onces lifted doesn't start dropping in power until about 10,250, then I think you're reaching the limits of the stock valvetrain. (this is first hand experience btw, so don't ask for "magical internet references). I don't have any hard numbers for what I've seen on that engine configuration, but I can say that as far as RPM's go, those motors are wild.

 

That run was on 93 octane. I've seen this motor in person in Larry's civic hatchback. It's a nasty street engine not some road race special. Larry told me he shoots for the most total amount of flow for the entire amount of time the valve is open not just peak flow numbers. There's a lot of neat stuff that isn't listed in the article on that engine. For example, there a splash guards inside the block to keep the oil draining back to the pan from splashing onto the crank. Larry also has load cells mounted against the cylinder liners and his ECU will pull the timing back when the cells measure any cylinder deflection. He also uses some tricks that you see on streetbike engines. Endyn also used to be big in NASCAR and Pro Stock before Larry got sick and had to take a break. Larry did the heads on Bill Elliot's car when he set the top speed record at Daytona in the early 80's. Needless to say he's getting the call when I build my engine

 

Honda B motors are amazing. The ITR motors are great right out of the box but all the other B engines have as much potential waiting to be unleashed. My old Civic(a heavy ass coupe) had a plain non-vtec B20 out of a CR-V. The only mods I did was a thinner head gasket, Integra intake manifold (deburred and portmatched to the TB), cheapo header, CAI, exhaust, and a reflashed ecu. Lots of fun.

[Touge]

I actually discussed building an L-series with Larry back in 2006. The plan was to use and LD block and use an L24 crank so I could run a long set of rods. Larry was going to weld and reshape the chambers and install the pistons to re-create one of his old NASCAR engine designs. With the right valvetrain I could make power all the way to 10,000 rpms.

 

He also joked that for all that work I could just do an LS swap and be done with it.

[Gollum]

He's right. Sticking with the L series in the long run can be very counter productive from a financial and practicality standpoint. But they sure can be fun motors.

 

I was also going to mention, that the L24 and L26 have around a 1.8 rod/stroke ratio, which isn't bad. And you can still bore a bit over what the L26 is at. The NA guys get away with running a 3.1 or 3.2 liter setup, but under high HP boost application they tend to fail at the bore level, most likely due to warping out of round.

[Touge]

He's right. Sticking with the L series in the long run can be very counter productive from a financial and practicality standpoint. But they sure can be fun motors.

 

I was also going to mention, that the L24 and L26 have around a 1.8 rod/stroke ratio, which isn't bad. And you can still bore a bit over what the L26 is at. The NA guys get away with running a 3.1 or 3.2 liter setup, but under high HP boost application they tend to fail at the bore level, most likely due to warping out of round.

 

I agree with Larry re:engine swaps. I just can't stomach the thought of putting a GM product in a classic Japanese sports car. Now a VH45DE would be right in my way of thinking. However, I do love the sounds of a screaming straight-6. For me, it conjures up images of vintage Le Mans and Steve McQueen's XK120 tearing ass through the canyons or along the PCH. A 90 degree V8 makes me think NASCAR unless it's mounted behind the seats in a GT-40.

 

My apologies to the OP for the hijack. My advice would be to read up on how motor geometry affects the rest of the engine. You can always email Larry staff@theoldone.com. He's usually pretty busy but you will get an answer back.