Aftermarkt cams for a Caldina 3S-GTE

[fivebob]

I've discovered a major problem with the upgrade path for the Caldina version of the 3S-GTE, I can't find an inlet cam that will accept the cam timing trigger



Unless anyone knows of a supplier, the only options I can think of are to buy an exhaust cam and get the thread cut to bolt the trigger to. Not sure if this can be done though, as I don't know if the hole that's already there has been hardened or not.

Alternatively I could press fit a threaded plug into the end of the cam. This is probably the easiest solution, but I don't like to think about what would happen if it came loose.

Final option is to make up a bearing, seal, and drive arrangement that will fit on the stock distributor drive. Problem with this is that the stock cam cover hasn't got the other 1/2 of the bearing, requiring the use of an earlier model cam cover, or some welding and machining of the current one.

Has anyone got a better idea, an alternative supplier, or do you know if I can cut the thread in the end of an HKS cam?

[vvega]

just to clarafie this is for the dizzy drive or some sort of cam position sensor ??

not really to familiar with the caldena engine
oh and are you running the stock ecu with this setup or have you moved to the motec ??

??
v

[vvega]

you could look into welding the cap you speek of on and retempering the cam
that would depend on the skill of the welder you ask to do it
or a internally splined cap and some locktight
i see no reason why you couldnt spin it up on a lathe and drill and tap it
cams are only case hardened after all

if you are running aftermarket and this is the dizzy drive why not just run a crank angle sensor off the crank ??

sorry i posted before you replyed gotta run out to pick up another mr2

from your parts attually too
so if you see a blue aw11 with a plexyglass rear hatch do wave

lol

v

[fivebob]

just to clarafie this is for the dizzy drive or some sort of cam position sensor ??

not really to familiar with the caldena engine
oh and are you running the stock ecu with this setup or have you moved to the motec ??

The pic shows the cam position trigger bolted to the end of the crank, there is no dizzy on a Caldina engine it's direct fire ignition.

I'm in the process of moving to the Motec, just rebuilding my spare engine ATM so I thought I'd see if the HKS cams I had would fit.

you could look into welding the cap you speek of on and retempering the cam
that would depend on the skill of the welder you ask to do it
or a internally splined cap and some locktight
i see no reason why you couldnt spin it up on a lathe and drill and tap it
cams are only case hardened after all

Hmm don't like the idea of welding and re-tempering, and an internally splined cap would require an spline to be made in the cam, which would have the same if not more problems than the threading option. I thought they were only case hardened, but don't know if that's only the lobes or the whole cam, in which case the hole that's already there will be harderned as well. Guess I'm just going to have to take it to an engineer to find out.

if you are running aftermarket and this is the dizzy drive why not just run a crank angle sensor off the crank ??

Cause you still need a #1 TDC position sensor to run sequential injection/ignition and I can't see any easy option for doing this, maybe I could use the cam pulley and mount a Hall effect sensor, but that will be a PITA to manufacture.

sorry i posted before you replyed gotta run out to pick up another mr2

from your parts attually too
so if you see a blue aw11 with a plexyglass rear hatch do wave

unless you're travelling out in the sticks, probably not as I'm going up to my secret workshop right now.

[vvega]

haha
i am going out the the sticks whapaka or somthing

with the spline you only put it on the cap
and make it a mechanical fit not a interferance

as with the need for tdc thats eazy you just remove to tooth from the crank cam(motronic) and call the first trigger your home then work out a tooth offset and set it up as tdc
basically what ive done with my haltech

i prolly havent explaned it to well

ive yet to see a fully hard cam and if its hks it will be made from a billit and the case hardend
i think thats the way to go as it wont require retempering though you stand a chance of upsetting the internal oiling but nothing that is hard to fix

[fivebob]

with the spline you only put it on the cap
and make it a mechanical fit not a interferance

Sorry I don't quite understand, what does the spline mate up to to give you a mechanical fit, and what retains it. The HKS cams only have a slot for dizzy drive and I can't see a way if putting a spline there or retaining a trigger using the dizzy drive.

as with the need for tdc thats eazy you just remove to tooth from the crank cam(motronic) and call the first trigger your home then work out a tooth offset and set it up as tdc
basically what ive done with my haltech

Stock Caldina crank sensor is already 36 tooth with two missing, but that doesn't help with sequential injection/ignition. The ECU still needs a signal for #1 TDC on the power stroke ie once every two revolutions. Doing it as one tooth missing on the crank doesn't give you the required signal, therefore you can't run sequential, only batch or semi sequential and wasted spark.

ive yet to see a fully hard cam and if its hks it will be made from a billit and the case hardend
i think thats the way to go as it wont require retempering though you stand a chance of upsetting the internal oiling but nothing that is hard to fix

I'll take some pics of the HKS cam later and post them up, not sure if they're made from billet though, looks more like they're cast or forged.

[anthonym]

Lynn Rogers told me he has had good results reprofiling VVTi 3SGE cams for race engines, normally I wouldn't consider this as an option, but I doubt Lynn would do it without putting a reasonable amount of thought into it. He has also mentioned he has access to billets which can be custom profiled, but I can't remember which 3S variant we were talking about at the time, probably gen 3. It would be worth a visit IMO, and not too far away from your secret Auckland shed .

[Celica RA45]

bob im using the motec system on my altezza 3sge using the crank as in ref still has all the teeth and using cam sensor as the sync .the cam problem you are talking about ,it has a ball at the exhaust cam and all so on the gen 2 and 3 cams from memory take ball out then drill to required size and tap for new bolt to go in problem solved .
Q is the no 1 cam journal bigger than no 2 like in the altezza 3sge or are they the same .

[Celica RA45]

another 1 is to make a sleeve and fit the cam sensor pickup over it i did this on my 1st beams motor single vvti red top and this worked as i was using gen 2 cams

[RunningRich]

<Engineer hat on>

Toyota cams (early 90's) had the cam surfaces locally heat treated using (effectively) a CNC TIG torch. This rapidly raised the temperature of the surface without excess heating.

I would expect a cam to just be case hardened. This prevents breakage of the cam given they would have a nice ductile core.

My choice would be simply to drill an tap the end of the cam. If you didn't want to do this yourself I'd recommend finding a toolmaker or machine shop with tool steel experience.

<Engineer hat off>

[fivebob]

Thanks for that. I think I'll take them to a toolmaker and get it done, might just have a talk to Lynn Rogers as well

I did some testing on the HKS cams and they don't appear to be hardened where the hole is, but there is a ball bearing in the end of both cams. The pics are a bit crappy and don't show it that well, but the one in the inlet cam one is only 5mm from the face, so it would have to be removed, not sure how. The exhaust has about 15mm so there would be enough room for a thread.

I'll also need to drill a hole in the end, like the one in the stock cam, for the locating detent in the trigger. Shouldn't be too critical as I'm using the Motec, and it's only for a sync signal anyway.

If I have to use an exhaust cam for the inlet I'm tossing up between using a 272° & a 264° (not sure which way around) because I have a set of both or buying another 264°... decisions...decisions

Gen IV inlet cam



HKS inlet cam


HKS Exhaust cam



Oh and just for fun, the inlet valves out of FarmerDaves #1 cylinder, think I can use them again

[10k 20v]

another option is getting them built up and reprofiled.
before you flame me for that comment as you probly really want to use the cams you currently have.
i'm not a fan of welding and re-profiling and would much rather buy a billett item from the start but i know of a few race engines that have had it done with no problems