SVX gravel rally car...surely not? Absolutely...

[dynomatt]

Lets work off the inlet only.

Factory duration at 0.050" is 190 ish...can't recall exactly, but we did map it.

Mine are 230 degrees at 0.050"

The factory inlet opening point in the manual of 4* is *assumed* to be seat to seat duration, not 0.050". If you do the maths there, it becomes a seat to seat duration of 236*.

Given that, we picked 2.5* inlet opening, but at 0.050"...so to compare properly, it would be (very roughly) about 28* inlet opening and about 70 something degrees closing.

Does that make sense?

I think we aimed for a lobe separation angle of 112 degrees...versus factory of 114.

Of course we have no idea what was actually installed!!!

M

[RallyBob]

Originally Posted by dynomatt

Lets work off the inlet only.

Factory duration at 0.050" is 190 ish...can't recall exactly, but we did map it.

Mine are 230 degrees at 0.050"

That is in line with what I remembered. I never mapped the @ .050" cam timing events myself...wish I had now for comparison purposes!

The factory inlet opening point in the manual of 4* is *assumed* to be seat to seat duration, not 0.050". If you do the maths there, it becomes a seat to seat duration of 236*.

As I do not know the factory intake closing specs, I must take your word on this!

Given that, we picked 2.5* inlet opening, but at 0.050"...so to compare properly, it would be (very roughly) about 28* inlet opening and about 70 something degrees closing.
Does that make sense?

That would be 278-ish advertised duration. Again, I am taking you at your word simply because I do not know the correct numbers. Does you cam card list the advertised duration numbers at all? I am just inquiring as to how your numbers were calculated in the hope that your cam timing issue can be figured out. So far it seems like apples to oranges a bit? Unless I'm missing something entirely, we're essentially comparing stock advertised duration opening/closing events to your new camshaft's duration @ .050" opening/closing events. Confusing to say the least!

I think we aimed for a lobe separation angle of 112 degrees...versus factory of 114.

Of course we have no idea what was actually installed!!!

M

Should be good for more torque certainly, I tend to run very tight lobe separation angles for rally cars in the quest for a strong mid-range powerband.

[dynomatt]

Hi Bob,

The factory opening is 4* BTDC and closes at 52* ABDC...add 180 to both of these and you get 236*.

Advertised duration appears to be a bit random...depends on who you get to do the cam, hence we prefer the 0.050" figures as it's more testable. My *advertised* inlet duration claims to be 284* but you never know!!

To put it another way, we tried to match the centre lines, but tighten them up a bit, and hence, after much deliberation came up with the 2.5* BTDC @ 0.050".

I'd be interested to see what you did? You talk of 240 degree duration, which must mean your total duration is closer to 290? Did you just did you just add 27* to each side to maintain the factory angles? ie, have valve openings at 31* and closing at 79*?

(Math here is 290 (new cams) - 236 (factory) = 54* more duration, divide by two to maintain same angle)

M

[Johnybeas]

First time reading the thread, but I'm caught up... mostly. Any progress with the motor??? Have any of the cam timing things helped??? Awesome venture and I'd love to see a video of the svx in action with the wrx's and evo's when you get it back up to speed and enter again if people are attending would ya take some video?? and more pictures awesome project!

[dynomatt]

Thanks for your response.

Cam timing has been pushed back to the weekend due to availability.

We'll have to wait until then.

There was a short video of it, but no idea if it still exists...will try and find out.

M

[YourConfused]

I just went over every page in this thread and I want more! Update us please.

[subbieatnz]

yeas hows is it going?

[Nevin]

I too am curious how things are going! Best of luck with everything!

[Freeman]

It's a bit old.. Any update on this? I've torn through each page anxiously awaiting the end result...

[dynomatt]

OK...motivation has returned.

I pulled the cam timing apart earlier in the year. Turns out it was out a little bit, but not to the order I had hoped. So half win, half loss.

So after more than 18 months of losing my way, I've now found the road again.

I've set a target of doing a rally next year. Not sure when (could be December for all I know) but that's a target.

I've also made a decision to go outside my current rules set, if only to demonstrate that what I envisaged was possible. The rules for rallying in Australia prevent me modifying my car too much, however, there's a growing backlash to this which suggests that, in time, the rules will relax somewhat. For me, this falls into the engine category. I must utilise the standard inlet manifold and headers. However, if I could go to throttle bodies (aka Porsche setup) and extractors (custom headers in your language), then we would be in a different ball game.

I also need to manage the cooling problem. I'm hoping with big fans, existing PWR, Davies Craig electric pump, oil cooler, and better airflow through the engine bay (remove metal from the sump guard at the back) then we should be back in business.

I've bought a second SVX as a test mule, so hopefully will assemble the engine and install it into that to go testing (too hard to do proper rally testing).

So wish me luck as I start down the road again.

Matt

[TomsSVX]

great news... As for the cooling issue. Take a closer look at improving flow the to the rear cylinders on both banks... I believe this is where we are seeing "dead spots" where the water is allowed to boil

Tom

[dynomatt]

THanks Tom...has anybody got any photos of what needs to be done? Or any threads on this topic?

Thanks,
MAtt

[TomsSVX]

Originally Posted by dynomatt

THanks Tom...has anybody got any photos of what needs to be done? Or any threads on this topic?

Thanks,
MAtt

Right now its all theory. No one has been able to *cure* the problem... They can only lessen it w/ the parts you already have in mind.

Tom

[dynomatt]

OK thanks...understood.

Since the big end has gone in the rally cars engine, I'll probably be splitting the case soon and suss out the water flow. I have had experience with cooling issues at the back of blocks in their turbo cars but I've always thought it was a turbo issue. It's hard to imagine a modern engine manufacturer getting caught out by cooling design issues...although not impossible.

Matt

[Freeman]

Sorry to be a bit off topic on the over heating issue, but would you mind posting the final weight on the car? I know there was a LOT of work that went into reducing the weight but never a post on what the final weight was..