Japanese N/A L6 400hp, how they do it, pictures I've found, etc. Not 56k safe

[johnc]

They won't know I have a welded head either. Basically, all the internals are unknown and they don't check until someone complains. Only reason why someone would complain is if I spank them so much and they aren't use to a Z spanking them (or they're wiener babies). From there they would do a displacement check, see its 2.4L since you can do that without tearing down a motor. The club is pretty lax, and no one complains in there. As a flag waiver, I know some suspicious cars but it really widdles down to how much money you have. A lot of people will lose points in tech, but by winning 1st and 2nd they regain the points.

 

Or maybe someone reads about your mods on an Internet message board.

 

As a scrutineer for SCCA and NASA I suggest you disclose the mods on your car to the powers that be when you show up for the annual tech. They will find a place for you to race and have fun. If you show up as a newbie and then get caught cheating, you'll never live that down and it will follow you everywhere. Racing is a small community and word travels fast.

 

BTW... Unfortunately, now that I've read this, if you show up at an SCCA event where I'm the Chief of Tech I will have a talk with you about car classing regardless of what car you're driving. Sorry, but that comes with my job. It will be a friendly talk and we will find a place in the event so you can race and have fun, but you won't take a trophy away from someone who complies with the rules.

[josh817]

I know what you mean however this group, CVAR is more friendly and have fun environment then competitive. I heard somewhere and I don't know if its true, but SCCA won't let you run if you aren't within parameters. I like CVAR because they just deduct points. The likelihood that I win 1st place and regain points is slim because this day and age, its become a sport of budget. There are no sponsors or anything but there are guys who have some very expensive cars. Point being, Porsche's run with the 1 or 2 Z's in CVAR this season and the Porsche guys have a lot invested. Cool stuff, within the rules (or maybe not we don't know), that have them 1-5 in the placing, and they lap the entire field twice in a 20 minute session at Texas World. Really good drivers + really good budget = winning. There is no way I could race with them, but I can race with the other Z guy who tags way behind them. CVAR follows SCCA rules for the year of your car, therefor whatever the Z did in SCCA in 1972, I can do too I believe.

 

Also it would be good to note that CVAR is a pretty lax place. You're mainly there to have fun, not to compete. Awards for 1-3 each season consist usually of the dead remains from someone blowing their motor rather then cash or going to "regionals". That's why I like it. Plus people know me now because of me driving in the Z for flag waving and I use to attend races with my dad as a little boy when he was in the club. Some of the Triumph guys who race are Dad's customers too so like you said, everyone knows everyone else. In a relaxed environment its a pretty cool place.

 

I don't mind if the tech guy or someone in CVAR stumbles upon my thread though. I'm going with a 2.4L displacement so I don't kill a V07 crank. During tech I don't believe they check displacement but they will check the block/head code and stuff I think. Believe it or not, most of the guys are running welded chambers anyway whether you know it or not, and I doubt a welded chamber is going to land me into 1st place, beating $150,000 cars. As long as I don't beat them on the track or in points, then there is no reason to argue or fight, unless the guy in second to last place is offended by me beating him I'm only there to have fun, which would explain why some other guys are there too. For instance, 3 dudes were running their Formula Atlantic cars with the Formula Ford group and spanking everybody, because they had already won last season. They are spanking everyone else but they weren't going for points. Last in points, first on track, because they want to have fun. CVAR is at the point where they will say OK you get no points at all, but you can run.

 

I honestly wouldn't mind NOT winning an award composed of oil soaked left overs and then being made fun of because how young I am compared to them, just as long as I can race along side of them. Hopefully that clears up any "you dirty cheating scoundrel" stuff. Lol

 

Link:

http://www.corinthianvintagerace.com/

 

[spork]

Somewhere on here the shaving of the rear flywheel flange came up. The idea was to prevent the crank from snapping right behind the flywheel flange. The harmonics involved all seem to go to that one point or something.

 

I'd like to see a little discussion on this part of the original post. Who else has heard of or done this modification? Can any real explanation be made. It seems I've heard a reference to this someplace before.

[260DET]

I know what you mean however this group, CVAR is more friendly and have fun environment then competitive. I heard somewhere and I don't know if its true, but SCCA won't let you run if you aren't within parameters. I like CVAR because they just deduct points. The likelihood that I win 1st place and regain points is slim because this day and age, its become a sport of budget. There are no sponsors or anything but there are guys who have some very expensive cars. Point being, Porsche's run with the 1 or 2 Z's in CVAR this season and the Porsche guys have a lot invested. Cool stuff, within the rules (or maybe not we don't know), that have them 1-5 in the placing, and they lap the entire field twice in a 20 minute session at Texas World. Really good drivers + really good budget = winning. There is no way I could race with them, but I can race with the other Z guy who tags way behind them................................................

 

Thats not the right attitude, it is the duty of every Z driver to race and beat Porsches, not to have fun

[josh817]

I'd like to see a little discussion on this part of the original post. Who else has heard of or done this modification? Can any real explanation be made. It seems I've heard a reference to this someplace before.

The guy from Datsun Spirit wrote about it. He's the one with the orange Z and the 6 bike carbs or "slide carbs" with the blue air horns I believe and the Gnose.

 

Other then that, all the blogs I saw said "crank modification" and within that there was balancing, and shaving the rear. On DatsunSpirits blog post he showed a picture. The picture I posted showed the flange being welded on further back. Someone made a comment on his blog post asking how much you should shave off and he said 6mm. That's all I know. A lot of the blogs had this modification noted in them so I suspect it is important. Here are the pictures from Datsun Spirit. His site appears to be down, I'm unsure when it will come back.

Edited July 22, 2010 by josh817

[timestep]

This should be sticked somewhere appropriate. The amount of information in this is staggering.

[Tony D]

It's a pilot for positive location of the flywheel. If you aren't balancing the flywheel properly, it can 'waggle'. That pilot they machine there is much like the pilot on a turbocompressor impeller used on the old Elliott PAP Plus (or for that matter, the original PAP introduced in 1964!)

 

There is nothing new here, just proper ENGINEERING applied to a problem someone is seeing. But is it the root cause solution, or band-aiding a symptom?

[spork]

It's a pilot for positive location of the flywheel. If you aren't balancing the flywheel properly, it can 'waggle'. That pilot they machine there is much like the pilot on a turbocompressor impeller used on the old Elliott PAP Plus (or for that matter, the original PAP introduced in 1964!)

 

There is nothing new here, just proper ENGINEERING applied to a problem someone is seeing. But is it the root cause solution, or band-aiding a symptom?

 

Well.. I understand the welding of the pilot, but why shave the rear of it 6mm? That's the confusing tid bit for me?

[josh817]

Lol I didn't bother to look at it more closely. No wonder it didn't make sense to me why they would weld on a flange that had a large amount of weight spinning from it. Could you explain further Tony, I don't think I'm getting it... or is it as simple as locating the flywheel on the flange and not letting it "waggle". In that case, wouldn't the locating pins/installing more locating pins do that too or are they meant only to protect the flywheel bolts from shearing? For a properly balanced flywheel I assume the welded pilot doesn't play a very important role?

 

As for an in depth look, I had a link going to BHJ Dynamics. I think that may explain it well. It kind of makes sense to me.... vaguely... As I said I believe it fixes the harmonics issue. MonzterZ, the guy I mentioned earlier and I think he posted in here, had a crank snap on him I think, plus I have that one picture I think I showed too...

Link: http://www.bhjdynamics.com/downloads/pdf/tech/BHJDynamics_Damper_Info.pdf

Picture:

 

My last question is if you're going to buy the nice flywheel and clutch setup, the ones that are multidisked and the entire setup is like 10 pounds, does that get balanced with all your other rotating masses or does the $1200 get you bolt on flywheel+clutch setup? Just out of curiosity.

[Flexicoker]

Doesn't the flywheel already pilot on the OD of the rear of the crank?

 

My first thought when seeing the 'shave 6mm' modification was that is purpose was to shorten the length of that segment of the crank, in order to move any torsional modes to a higher frequency, and out of the (now higher) RPM range of the engine. However, that portion of the crank is so short and large in diameter that it doesn't seem like this would do much. Especially since a lower moment of inertia flywheel could have a much greater impact on that harmonic.

 

Maybe instead, that is a solution to bending vibration caused by the combination of cyl6 firing, and cantilever mounting of the flywheel? (section 8 of the BHJ link Josh posted)

 

Some close up pictures of Monzster's crank failure might help to explain whether the fatigue failure was in torsion or in bending.

[Tony D]

Unfortunately I can not talk about anything more than I already have other than to say there are engines out there not in drag-racing service which rev FAR higher than this one and whi B)ch do not have the shaved crank for piloting of the flywheel.

 

As for dowels, they are normally a shear item. They can also locate, usually in reference to balancing of the assembly. One can work as well as 8 in this instance with flanged cranks.

 

No clutch cover and flywheel is balanced to bolt on, period. Not if you are serious about racing.

 

Let me add this: You obsess about the shaved crank. Anybody got a photo of the flywheel's crankshaft side that mates with that modified crank? May want to take a look at that to understand what they are doing. The 'before' crank tells you a lot...

[josh817]

Lol Tony you leave us shrouded in mystery all the time. I'm curious about the flywheel and clutch setup. Some are running multidisk but some are also running single disk, all are extremely light. I was just going to go with Quartermaster or 10000RPM system. Expensive, but long term project, so I try to ignore the sum total and focus more on individual purchases.

[260DET]

Doesn't the flywheel already pilot on the OD of the rear of the crank?

 

My first thought when seeing the 'shave 6mm' modification was that is purpose was to shorten the length of that segment of the crank, in order to move any torsional modes to a higher frequency, and out of the (now higher) RPM range of the engine. However, that portion of the crank is so short and large in diameter that it doesn't seem like this would do much. Especially since a lower moment of inertia flywheel could have a much greater impact on that harmonic.

 

Maybe instead, that is a solution to bending vibration caused by the combination of cyl6 firing, and cantilever mounting of the flywheel? (section 8 of the BHJ link Josh posted)

 

Some close up pictures of Monzster's crank failure might help to explain whether the fatigue failure was in torsion or in bending.

 

From memory a L6 OE flywheel pilots on the ID of the rear of the crank, VG's certainy do. Guess the modified crank could have been done to move the flywheel forward to provide more room for a multi plate clutch or something but your explanation makes more sense to a layman like me.

Edited July 28, 2010 by 260DET

[jc052685]

Thought this might belong here. Some pics of the heads from the shop in japan.

 

46mm int. / 38mm exh.

 

 

 

 

[Tony D]

what shop in Japan?

[jc052685]

Auto Shop Watanabe

[josh817]

Yep the Watanabe website is where I got the exhaust header photo that mentions a cyclone effect... They too sell the Wako 75S camshaft.... if that means anything to you guys. The head posted above is an L4 head. Pretty.

Edited November 4, 2010 by josh817

[Tony D]

Link? Maybe I should put a stop on my list next visit...

[Tony D]

I think the easiest route for a 400HP L6 is to pay Dave Rebello the $8000, and supply him the block and head, carbs and E-Motive HPV1 setup and go from there. In about 6 weeks (more or less) the crate show up with a dyno sheet and a completely tested, waranted engine...

 

That's how you get records at Bonneville, so Burton tell me! Do the math on Top Speed, CD, Frontal Area, Altitude at Competiton Point, and correct for sea-level and you will be amazed that the long block can be had so cheap...so easily!

[josh817]

How depressing.

 

Link = right click on photo >>> properties >>> url for photo >>> cut off unwanted bits >>> ???? >>> win: http://www.as-watanabe.com under the "works" tab.