Cam help!

[Maddart]

G'day blokes.
Haven't intro'd myself yet. (Speed Trip nut and Buell owner at present)
I'm helping out a mate with a '98 sprint st that 's been riding a mates Daytona lately and he sorely wants to upgrade the Sprint cams to Daytona spec., but not sure if they are a straight swap, (with remapping) , or if the valves and heads are different? (I know they run different size plugs)
Also is there an aftermarket alternative and source?
Any advice much apreciated!

[DaveM]

Hi Maddart,
I'm not technical enough to help but there are several here who are.

Stlakid is one fellow here who knows a lot about these engines but he is not the only one.

Good luck.

DaveM

[Maddart]

Thanks Dave. Looks like a great site.
Here's me old fightered Daytona.

[DaveM]

Maddart,
that is a pretty souped up looking beast. You have been busy on that one!

Try PM to Stlakid if he doesn't know there are quite a few pretty knowledgeable types here about the technical bits.

I am just not one of them I'm afraid

Unless you have a tyre question and then I wont shut up!

Yes it is a great site, thanks,

DaveM

[Maddart]

Oh go on then Dave. Tell me about tyres..... he he

[DaveM]

Well they are round and black!

DaveM

[Jhumphrey]

I havent run across any information which would indicate they are not a direct swap, but a quick setup in the V blocks with a dial indicator can compare total lift. You would definately need to remap FI to compensate for lift duration, simple matter with a tuneboy. Its my understanding that connecting rods and possibly pistons in the Daytona are lighter weight allowing faster rev's. I'm not sure what you'd gain given the same heads and porting, but ... be fun to try. I dont know of any aftermarket cam suppliers. I know I didnt answer your questions, just my .02 worth.

[kludge]

I don't know for sure, but I have also wondered about this. What I have read largely coincides with this site: http://www.hermys.com/triumph/sprintst/2000/

That states the differences between the units as:

Cylinder liners (steel instead of coated aluminium).
Pistons (to match liners).
Camshafts - revised lift and timing to boost midrange power
EFI - engine management system is digitally remapped to match the new characteristics of the engine.

I have read in many places that the Daytona pistons are forged while the Sprint items are cast. I think I seen it claimed in a few places that Daytona also has stiffer valve springs to cope with the increased valve acceleration and increased lift. The Daytona tunes can be loaded into the Sprint ECU.
The exhaust systems are different. Look in the Sprint forum for the guy who is putting a Daytona engine into his Sprint ST and made a hybrid exhaust system. Lots of info and ideas there.

IIWY I'd start comparing part numbers before buying any new bump-sticks, or wait for someone who's made the swap to chime in. :wink:

[RexxyPup]

It's a awfully expensive thing to do, turning the Sprint engine into the Daytona one.

I'm the guy changing the Sprint engine for the Daytona one, and I have made my own exhaust as it is much larger bore. I would have a serious think about getting a Daytona engine off eBay rather than converting yours. I damaged the cylinder head of my ST in June, and simply to replace that was £1,200 in parts, and that is leaving alone the fact that there are all sorts of shims to set the cams in the heads, and from memory, I think they come matched to the head, although you can get shim packs.

I would recommend giving Sandy at Triumphant a call to see if he would send you a Daytona engine. I am paying £800 for what is effectively a 0miles recon unit. Other than the exhaust, there are minor issues with the Oil cooler feed pipe locations, but Sandy seems to thing that is no big deal.

Seriously, tot up the cost of the parts to do the change, and the time and chance of getting something wrong, then look at the cost of having the unit shipped out to you.

You will also need to get Tuneboy to put the Daytona tune into your ECU, and you may loose the use of the fuel gauge as the 'tona doesn't have one, but I the jury is out on that score.

I have a thread running on the project so far, and have reached a pause while waiting for the engine. you can find it here. You may want to wait and see how I get on

Rexx

[Maddart]

Thanks for the replies blokes. I'll relate this back to old mate and follow your progress Rexx.

We're having a chat to the local camgrinder for some ideas and I'll relate that back to you.