Big bore stroker builds on the dyno

[CFM]

I posted this recently in the sport ATV section, and although this is about a LT-Z400 ATV, they share a top end with the DRZ, so I thought some of you might find this information interesting and/or useful.  These builds are done to Z400's that are meant for racing, but this could be replicated in a DRZ.  Some small changes in compression, and valve events, and you have a pretty wicked DRZ engine.

Not all dyno's are alike. I'm not looking for a pissing contest. I'm not claiming these will make any certain number on any certain dyno. This is a Dynomite Dyno from Land & Sea, at CFM Motorsports in Ceylon MN. For reference, a stock KFX 400 made 32hp on this dyno. One with a big bore and a Pro Circuit full system with open air box, made 36hp.  If you're familiar with Pete Hager, or with Raptors, Pete's Raptor 700 with a Rossier FS and a FCI intake made 56hp on this dyno. It's featured in one of his YouTube videos.  

 

 

I'll start with the little guy. 462's are pretty popular, as they're a bulletproof build with a lot of bang for the buck! Being 62cc's over stock, they do need some help breathing if you want results.  This is my 'do everything' machine. It's a 462cc ripper that would be ideal for MX, XC, dunes, trails, whatever. The cams are racy, but it's responsive with no dead spot down low. The thing is a blast to ride. It was kind of a spare parts build, but it just works. The head is actually in a bad need of an update. It has +1 valves, but the airflow is not on par with the others I'm posting.  This will get an update eventually. 

57 hp 39ft lbs

Fuel: Turbo Blue 110 race fuel

Displacement:
462cc +4 bore cylinder works cylinder, +4 Hotrods crank, High compressioin CP piston (The old VCP 14.25:1 piston from Venom with slight modifications bringing it down to 14:1)

Compression ratio:
14:1
Valvetrain:
Custom Web cams, +1/+1 Ferrea valves, all from CFM Motorsports, Kibblewhite springs

Induction:
FCR 42.5 with the carb to head boot from a 05 TRX 450R, the intake is a Fuel customs intake for a carbed YFZ, and it has been shortened about an 1.5"

Porting:
The head is a +1 head from CFM Motorsports, which is in bad need of an update. The airflow is not on par with with my current heads

Exhaust:
Barker Full System

Ignition:
Dyna Programmable ignition box, curve #1,
Stock coil, CR8E

Flywheel:
DRZ

Tires used:
20" Duro street tires

Gearing:
13/38 JT sprockets, RK X ring chain

 

 

 

Next is a Z482 that belongs to one of my customers. This is a little more of a pump gas drag race setup, as you can see by the stair step in the torque before 6000 rpm. This one has been dominating some 180 drags in the 400 and 450 class, where he races. 

63hp 40ft lbs

Fuel: VP U4.4

Displacement:
482cc  +6 bore, Ice Cube cylinder, Max Power custom CP piston. This piston is actually holding this build back a little, as the valve reliefs are not deep enough, and certain measures had to be taken to make it work, which lowered the compression, and limited the cam timing.

+4 hot rods stroker crank


Compression ratio:
12:1 roughly, because of the extra base gasket thickness needed to get piston to valve clearance

Valvetrain:
Custom Web cams, +1/+2 custom Ferrea valves, all from CFM Motorsports, Kibblewhite springs

Induction:
FCR 43.5 carb bored at Dasa, 190 main NKRT needle on the 4th, 50 pilot, QS3 FCI intake for a 06+ TRX450ER shortened 1"


Porting:
+1/+2 porting by CFM Motorsports

Exhaust:
Empire Industries

Ignition:
Dyna Programmable ignition box, custom curve from KFXGUY,
Stock coil, CR8EIX

Flywheel:
Trail Tech -16oz

Tires used:
20" Duro street tires 

Gearing:
14/40 with a non o-ring chain

 

 

 

The next one is very recent. This is my own Z490. This is a TT machine that I use for ice racing. It was setup just like the 482 above, and was making about 65hp, but like that one, it was lacking at 5000 rpm and lower.  I made a cam change, which picked up the torque sooner, and had it limited to about 62hp. I've wanted to try an EFI head for a while, and I scored a used one last summer. So I ported up the EFI head, just like one of my +1+2 heads, and that gave up nothing, but gained 2hp. Then I tried out a Vision Air V5 intake for a Honda 450. It didn't really fit before, but did with the straighter EFI head. That picked up a couple more.

So now, start to finish, I set out to make more torque down around 4500-6000 rpm, which I did, thanks to the smaller cams. I was willing to give up a few HP to do it, but I actually gained 1. As a bonus, my peak torque even bumped up a couple ft lbs, and my jets got smaller. What more can I ask for?

67hp 42ft lbs

Fuel: Turbo Blue 110 race fuel

Displacement:
490cc, +6 bore cylinder works cylinder with the water passages welded shut, and holes drilled to match the head gasket, and o-ringed. (This was a band-aid, don't use the cylinder works cylinder)
+5 hot rods stroker crank, +6 custom JE Piston only available from CFM Motorsports


Compression ratio:
13.5:1

Valvetrain:
Custom Web cams, +1/+2 custom Ferrea valves, all from CFM Motorsports, Kibblewhite springs

Induction:
FCR 44mm 172 main NKBT needle on the 2nd clip, 42 pilot, Vision Air V5 intake for a TRX450r


Porting:
+1/+2 porting by CFM Motorsports

Exhaust:
Empire Industries shorty

Ignition:
Dyna Programmable ignition box, custom curve,
Stock coil, CR8E

Flywheel:
Trail Tech -16oz

Tires used:
20" Duro street tires

Gearing:
14/40 JT sprockets, RK X ring chain

 

 

 

 

 

 

The final sheet is the same 490cc engine above, but this was last winter, before the EFI head.  This is a drag racing build on methanol, which I must say, is a very interesting fuel. This may need a little fine tuning yet. It was R&D for a drag build that I will be finishing soon.   I wasn't familiar with the screen snipping tool yet at this point, so this is a scan of the dyno sheet. 

70hp, 44ft lbs.

Fuel: Methanol

Displacement:
490cc, +6 bore cylinder works cylinder with the water passages welded shut, and holes drilled to match the head gasket, and o-ringed. (This was a band-aid, don't use the cylinder works cylinder)
+5 hot rods stroker crank, +6 custom JE Piston only available from CFM Motorsports


Compression ratio:
13.5:1

Valvetrain:
Custom Web cams, +1/+2 custom Ferrea valves, all from CFM Motorsports, Kibblewhite springs

Induction:
Mikuni HSR 45 with no main jet, a drilled needle jet, and a Thunder Products power valve. FCI intake for an early YFZ, with the insert.


Porting:
+1/+2 porting by CFM Motorsports

Exhaust:
Empire Industries shorty

Ignition:
Dyna Programmable ignition box, custom curve,
Stock coil, CR8E

Flywheel:
Trail Tech -16oz

Tires used:
Big heavy 20" Duro street tires on steel rims. (only non knobs I have sitting around)

Gearing:
14/40 JT sprockets, RK X ring chain

[Gsxrstuntdrz]

Good info!!

chuck did my 462 head, haven’t had a chance to spin it on the dyno yet but beyond impressed, absolutely wicked for “just a DRZ”

[Syntax_Erol]

Very nice info, but the price of webcams hits diminishing rate of returns for me, any info on a stroker big bore with hotcams would be also nice 

[Gsxrstuntdrz]

Way beyond “cost effective” here, I’ll be the first to say I’d rather just buy a 450 than do another full blown stroker build but turning a DRZ into something it was never supposed to be is a blast. Cams are a big piece of the puzzle not worth doing with hot cams in my opinion

[CFM]

7 minutes ago, Syntax_Erol said:

Very nice info, but the price of webcams hits diminishing rate of returns for me, any info on a stroker big bore with hotcams would be also nice 

 

This is the same Z462 with the new style hotcams stage 2. This, with a little less compression would make a great DRZ street build.  The big difference from above is the RPM's where it's useful. 

For what it's worth, there are options from web that can do this type of powerband a little better. 

Edited December 16, 2020 by CFM

[CFM]

30 minutes ago, Gsxrstuntdrz said:

Way beyond “cost effective” here, I’ll be the first to say I’d rather just buy a 450 than do another full blown stroker build but turning a DRZ into something it was never supposed to be is a blast. Cams are a big piece of the puzzle not worth doing with hot cams in my opinion

What this has always been about for me, is showing up to race, and cleaning house with an underdog. This engine has so much potential that people don't realize. It does cost some money, but in ATV's, the 450's aren't making this kind of power without just about as much work.  

 

In this video, I'm on the 462 from the above post (actually when it had a little less torque) To my left is a 480 YFZ with a guy who's a good 120lbs lighter than me, and to my right is a guy on a 310r 2 stroke. What you don't see are 2 or 3 Honda 450's that were also on the line. The little 462 definitely holds it's own. I'm about 280lbs.   I should also add, my 490 has pulled a holeshot on all of those guys.  It was apart at the time of that video. 

Ice race video

Edited December 16, 2020 by CFM

[ohiodrz400sm]

This shows a snapshot of the evolution of my DRZ400SM. Unfortunately, I only have from 434 on(no stock baseline). It's on a Dynojet dyno, SAE correction belonging to Mickey's Rolling Thunder in Newton Falls Ohio. The pulls were for entertainment only.

The lowest pull "green"  represents the typical 434 build.

43.6 hp tq 30.5

Fuel: pump 91

Displacement: 434cc Cylinder Works +4 kit. Vertex piston 

Compression ratio: 12.2.1

Valve train: NSHC, stock DRZ valves

Induction: FCR-MX39, 155 main, EMP 3rd, 45 pilot, 9mm float.  Sudco intake bell stock SM airboot, 3x3 airbox opening.

Porting: stock

Exhaust: MRD Z Pro

Ignition: stock

Flywheel: Trailtech -8 oz

Tires: 150/60-17

Gearing: 15/38

 

The next pull "purple" represents a 462cc with a carburetor not fully opening. After switching to a quick style throttle tube, the Dynatek ignition read that the throttle was now opening to 120%

47.5 HP TQ 33.6

Fuel: pump 91

Displacement: 462cc, Cylinder Works +4 cylinder / Hot Rods +4 crank/ Vertex piston

Compression ratio: 12.1:1 (3 layer base gasket)

Valve Train: Ferrea standard size valves, DRZ springs. Web 540's lca 106/104

Induction: FCR-MX 41, 175 main, EMR 4th, 42 pilot, 9mm float, R&D Power Bowl 2, 55 leak jet setting equivalent setting. Sudco intake bell, Malone Velocity intake tube, 3"x5" K&N filter. Top of airbox removes. Sides vented rearward of filter like a KTM/Husky

Porting: stock

Exhaust: MRD-ZPRO

Ignition: Dynatek. Custom map. Basically +4 map to 7k and then stepped back to stock timing

Flywheel: Trail Tech - 8 oz

Tires: 150/60-17

Gearing: 15/38

 

The top cluster is basically the same as the above 462 with the new throttle tube and different cams.

53-ish HP TQ 35-ish

Zeta Quick turn tube.

Cam: Web 539s 110 lca.

I have since swapped to a CP piston, shortened the intake 1 inch, and added a .5 inch longer filter. Future plans. Hope to get Mixxer's porting and have the carb bored to 42.5mm

Edited December 16, 2020 by ohiodrz400sm

[Syntax_Erol]

Meanwhile im hoping to get somewhere arround 45 48hp with my big bore, and stage 2 cams fuelled by efi. When engine taken apart and if i find the clearences close to out of spec may also put a stroker crank or just replace conrod/big end bearings. Not sure on stroker and hotcams combo in both value and relaibility(valves not opening eough may create head gasket issues dunno)  

[roleyrev]

Good info and interesting to boot. So you have an “efi” head ported. Have you efi to fit to it?

[CFM]

1 hour ago, roleyrev said:

Good info and interesting to boot. So you have an “efi” head ported. Have you efi to fit to it?

No, an FCR fits in the stock boot. The boot was matched to the FCR size and the new port size. The whole point of that project was to see if the EFI head had anything more to offer than the carb head. It had more airflow, and made more power. 

 

This was not done on a machine that had EFI, but it could be. It would require a throttle body appropriate to the new horsepower level.  A power commander would suffice to tune it on a dyno. There's a possibility of needing a bigger injector at some point. I wouldn't know what that point is, without having tried it. One thing I did do once, was modify a Z head to accept a throttle body for a LTR450. 

[Syntax_Erol]

So an efi atv head flows better than carb head ? Interesting... 

[CFM]

1 minute ago, Syntax_Erol said:

So an efi atv head flows better than carb head ? Interesting... 

Actually the EFI head is quite a bit worse flowing in stock form. After porting, they flow better. 

[ohiodrz400sm]

12 minutes ago, CFM said:

Actually the EFI head is quite a bit worse flowing in stock form. After porting, they flow better. 

What's the different between the 2?  I remember reading in a press release that the intake port was reshaped but I forget the rest of the details.

[CFM]

7 minutes ago, ohiodrz400sm said:

What's the different between the 2?  I remember reading in a press release that the intake port was reshaped but I forget the rest of the details.

The intake port of the EFI head enters the head pretty much straight from the rear, unlike the carb head that is angled.  The floor is a little taller, which allows a nicer shape on the short side.  That's the end of the benefits. The whole intake port and throttle body are smaller than the carb head.

At first glance, one would think the smaller intake port would be a good thing for velocity right?  Nope, velocity is relative to airflow, and there is so little airflow for the size of the port, that the velocity is poor as well. My ported head is a lot bigger (for 490cc's) and has dramatically more airflow, and higher velocity than the stock EFI head. 

Suzuki isn't stupid. They know how to make it into what I made it into. They made it tiny, trying to make the Z400 ultra trail friendly. You have to remember that their objectives are not necessarily the same as ours. 

 

 

[CFM]

Here are some photos of the ported EFI head. The angle of entry, for the intake port is nice and straight. Air prefers to go straight. 

 

 

 

Here's a carb head ported to the same equivalent.  The first picture especially, you can see the angle of entry for the intake port.  The angle of entry in the carb head does limit airflow a bit.  Air prefers to travel in a straight line. 

 

[FBRConcepts]

This is an awesome thread!   But kinda just died, are there any updates?