Daytona Project

[1979DaytonaSpecial]

New Member with a long overdue project. The last time I rode it was 1986, then it sat, then it was stolen in 2014 then recovered in 2016 and sat till now. I have been collecting odds & ends for it since it was recovered, so I think over the winter I am going to go thru it.

Bike Specs: It's a Tom Turner build with a heavily ported 434cc big bore kit, with I believe either TZ or RZ reeds with 34mm Mikuni's and I assume their his Chambers. I parked it in 86 after I picked up an RZ, but that's another story.

When it was parked it ran beautifully no issues but because of the time it sat the engine will need all new seals to start with, and I should have the crank checked out, so I have been checking around to see who's available and does good work.

Any suggestions would be appreciated.

[teazer]

No good mate.  That will never run again.  But since I like you, I am prepared to take it off your hands and I won't even charge a disposal fee......

It was worth a try..

Cranks are easy.  Loots of people can do those from falicon  to your local bike shop.  My preferred crank shop is Bill Bune in Anoka MN.  Chuck Quenzler (supertune) does any amount of RD and other two stroke work and would do a great job too.  I think that Lynn Garland and maybe Ed Erlenbach (EE) also rebuild cranks.

34mm carbs are quite large for a street motor, but should work.  RZ or TZ750 reed blocks are OK but there are probably better alternatives available now.  That said, an almost stock RZ makes about 54 hp and that can be stretched into the seventies with a bike of work.

Nice looking bike.

[Organicjedi]

Supertune Chuck, Garrett from GRA 2 Strokes, and Ed Erlenbach are on this forum and rebuild cranks for customers. You won't go wrong with any of them. Earl and Garrett are in CA if that matters to you.

It'll be interesting to see what you find as you open up that Daytona. Are the cylinders 2VO?

[SUPERTUNE]

Really cool that you kept it!
I'm sure you were very heartbroken when it was stolen.
I can't ever imagine that pain.
Florida is pretty far to ship to, but if not in a big hurry ground shipping can be reasonable.
I can email a price sheet to help you plan a rebuild.
Send me a PM or use my email in my signature.
Chuck

[GRA2STROKES]

I'm located in the Portland Oregon area and happy to help out. I actually just rebuilt a Tom turner engine that ate a rod and ruined a cylinder. Had a similar setup. I'll ad pictures and what not to my vendor section of my bore work head work and crank rebuilding.


Garrett

[1979DaytonaSpecial]

Thanks for the responses.

"No good mate.  That will never run again.  But since I like you, I am prepared to take it off your hands and I won't even charge a disposal fee......"  You know I was thinking the same thing. I can tell you really like me since you won't charge me a disposal fee, so thank you, but for now I am gonna pass on your wonderful offer, but if I change my mind I'll give you a shout.


" Are the cylinders 2VO?" I don't know the designation 2VO.  When I bought the bike I was told the big bore kit consisted of the cylinders re-sleeved to fit 66mm IT 175cc pistons and of course the port work. I have had the top end off for work, Turner had engraved the specifics on the cylinders.

As for 34's being large for a street motor, they provided excellent throttle response, I could roll on the throttle in 3rd and stand it on end.

I am researching my options to see how I will proceed.

[Organicjedi]

I'm located in the Portland Oregon area and happy to help out. I actually just rebuilt a Tom turner engine that ate a rod and ruined a cylinder. Had a similar setup. I'll ad pictures and what not to my vendor section of my bore work head work and crank rebuilding.


Garrett

My bad... thought you were in CA.

[Organicjedi]

Thanks for the responses.

"No good mate.  That will never run again.  But since I like you, I am prepared to take it off your hands and I won't even charge a disposal fee......"  You know I was thinking the same thing. I can tell you really like me since you won't charge me a disposal fee, so thank you, but for now I am gonna pass on your wonderful offer, but if I change my mind I'll give you a shout.


" Are the cylinders 2VO?" I don't know the designation 2VO.  When I bought the bike I was told the big bore kit consisted of the cylinders re-sleeved to fit 66mm IT 175cc pistons and of course the port work. I have had the top end off for work, Turner had engraved the specifics on the cylinders.

As for 34's being large for a street motor, they provided excellent throttle response, I could roll on the throttle in 3rd and stand it on end.

I am researching my options to see how I will proceed.

2VO is the Daytona prefix on the VIN. It's pretty common to find earlier 1A1 cylinders on them to get around the emissions controls. The cylinders are stamped near the base.

[SUPERTUNE]

Thanks for the responses.
" Are the cylinders 2VO?" I don't know the designation 2VO.  When I bought the bike I was told the big bore kit consisted of the cylinders re-sleeved to fit 66mm IT 175cc pistons and of course the port work. I have had the top end off for work, Turner had engraved the specifics on the cylinders.

As for 34's being large for a street motor, they provided excellent throttle response, I could roll on the throttle in 3rd and stand it on end.

I am researching my options to see how I will proceed.

I'm nearly 100% sure they're not re-sleeved and most likely just big bored.
Re-sleeving is not done with most performance engine builders as the transfer ports get hurt in size doing so.
A Yamaha IT175 66mm piston was very common mod at 424cc.
The next size up is 66.25 and would be a 427cc  and at 66.50mm a 430 cc engine.
Of course these are based on the stock 62mm crank stroke.

Technology has moved on today using TM flatslides like in my stg 2 builds and dyno video's.
TM34's not only perform better over old school VM's, but can have much better fuel mileage.
Even can go bigger with Lectron HV series like J. Spooner has running on thr street with his TZ replica bike.
Chuck.

[1979DaytonaSpecial]

That's interesting that it might not have been re-sleeved, but I am just going by what I was told, the guy I got the bike from said he got it from Turner in some type of trade deal. I may tear down the top end next week and take a closer look.  So what's the bore limit on a stock cyl ?  As of now at 66.25 mm the wall of the cyl's are .044" thinner which may not be an issue yet, but as walls get thinner they can start to distort then you loose ring seal.

I have a way to check this, if some one can measure the out side of the sleeve that sticks out of the bottom of the cyl, I would have a measurement I could compare mine too.

I am clearly not up to todays tech on 2 stokers, I am trying to recall what was done, I believe the reeds are from the RZ 350 which were some what larger than the stock ones. As for flat slides, their not needed to get it running.

[SUPERTUNE]

RD400's handle 66.50 no problem. Yes the thinnest area is the transfers mostly.
The ears look thin but are not an issue. These areas are not high piston load.
Ring seal is not a problem as the ring travel area is plenty thick.
After you exhaust all your bore sizes, then you just nikasil plate the bores.
Chuck

[1979DaytonaSpecial]

I pulled the top end off today.

It's @ 66.75mm Bore - 2.628", Engine size @ 434cc. The liner spigots out the bottom of the liners measure about .125" thick each, that I believe can go 4th over 1.0mm should the need arise. The current clearances are acceptable, so I'll just have the liners lightly touched and go new piston kits.

I have a question for anyone in the know: What's the recommended piston clearance to top of the cyl on a 400 ?

[SUPERTUNE]

Are you asking about piston to head squish clearance or piston to cylinder wall clearance?
All of these answers can be subject to the application of the engine.

With a modified engine... it's setup by the engine builder. (I hope)
At this bore size it going to be a IT or DT piston most likely. They came in 66mm as standard bore, so your at 3rd over with a 66.75mm.
Special machine work is required to fit them as the CD (compression distance) is shorter on those pistons and the dome squish angle is also different (less) so the heads need to be re-machined to match, then the compression ratio set after the machining of the squish.

Pictures and measurements would be needed to help determine what you may need as well as what fuel are you running or setup for.
Chuck

[1979DaytonaSpecial]

I hope everyone had a good thanksgiving. And I want to say I am glad it's finally over, I've started cooking @ 5am.

Yes I was asking about the squish clearance, or what I should ask, what is the factory deck height or squish clearance ?

The cyl's are marked on the sides 040/220, and I would assume that the tops were cut .040" and the bottoms cut .220" to make up for the shorter IT piston pin height, then Turner added steel spacers that went under the head bolts to make up the shorter cyl's.

What's the difference between the IT DT & YZ pistons ?

As for fuel, I ran premium, but here in California ours is 91.

[1979DaytonaSpecial]

I have been doing some reading on the specifics on my motor. I read that port locations effect performance, so I assume that the 35mm stock port location refers to the top of the exh ports location to the top of the liner, correct me if I'am wrong.

I mentioned previously about my motor having a big bore kit and using IT 175 66.75mm pistons. Now these pistons have a shorter pin height compared the the stock pistons, and to get these to work .220" was removed from the bottom of the liners, and apparently .040" was removed from the top of the liner to clean it up for copper gaskets. So that would make a stock exh port about 34mm from the top of the liner.

I measured several times and came up with a measurement of about 31.75mm to the top of the liner.

I used the 35mm port location because I don't think I have have 2VO liners, I believe their the earlier 400 liners that are 35mm to the top where 2VO liners are 38mm to the top, and the numbers I got from RD liner port maps on ERLENBACH RACING's site.