Best Cam For 1600 Rally Car

[stuart 31 3 Cars]

I'll be building a 1600 engine for my tarmac rally car soonish and was wondering which cam will be best suited.

 

I want to keep the rev limit fairly low (<8000rpm) for reliability and cost reasons as I want to use standard internals, slightly lightened and balanced properly though. I will be running it on twin 45 Weber carbs through a standard head and 4-1 exhaust manifold.

 

Also, I need to know anything else that I will need to do to get the best out of the cam, i.e. how much the head will need skimming to raise the compression ratio, dizzy re-curving, etc.

 

My main aim for the engine is torque with a wide power band at usable revs.

 

Cheers

Stu

[James_R 3]

If you plan to keep the std internals on the head (valve springs) you'll only be able to make to a 7krpm limit. a "285" sort of size cam woudl be the limit with that.

[j_turnell 137 3 Cars]

Also i'd imagine 45's slightly overkill with the spec your going for, 40's may be more suitable....

[stuart 31 3 Cars]

If you plan to keep the std internals on the head (valve springs) you'll only be able to make to a 7krpm limit. a "285" sort of size cam woudl be the limit with that.

 

Sorry by standard internals I meant pistons, rods, crank etc. I could do cheaper things like change valve springs to suit cam, get the pistons pocketed if necessary.

 

I have heard of a PTS 'max torque' cam but is that for a 1600 or a 1900?. Also, I've heard that you need to do some machining to the head for it to fit, does anyone know anything about that?

 

What about other cams? Catcams, Newman, do they do anything that would suit my requirements?

 

I've read a couple of peoples experiences with the piper 285 cam recently where they didn't getting the results they expected when running carbs, so was wondering if there's anything a bit wilder that I can get away with without having to fit forged internals and revving it to 9k rpm.

[welshpug 1,661]

that cam will work in either, I didn't need any machining at all to fit it, still clears the oil spraybar too.

 

any cam will need more compression though, but you can get good results with a heavy skim and a suitable cam pulley to compensate, no need to pocket the pistons as there's enough depth in the combustion chamber for most cams, though that all depends on how mad you go with the skimming.

 

doubt you'd need (or be able to) rev it to 9k, it's not a Honda

 

best bet is to find an engine builder that has built these before

Edited April 9, 2009 by welshpug

[richsmells 2]

I think James above built a rather hot 1600 using that cam.

[andychalmers 0]

Just a tip, if your new to rallying, I would leave the engine alone to start with as a standard engine will scare you if driven right. Also on a rally car you need a good all round cam to come in very low down with gradual power, standard cam is good to learn to drive with then upgrade if needed if need be. Reason being a rally car is always starting & stopping especially on hairpins, on a race or track car its totally different as there just flat out most of the time.

[stuart 31 3 Cars]

Cheers for the tips lads,

I am new to rallying, only done one up to now but thought the engine seemed a bit flat compared to my road 205 so thought about building another for when it pops.

I think fitting a lower final drive would help a lot, as when coming out of the tighter corners the revs were too low and I seemed to be waiting forever for the power to come in but even when in the power band, people were still pulling away from me.

 

As I'm building a fresh engine anyway though, I want to build one that will be reasonably competative with other 1600 machinery. Obviously I can't compete with S1600's and the likes but so long as it puts out around 150bhp and sounds right I'll be happy with that.

 

So is the PTS cam a good place to start if running on webbers, or are there better ones to go for?

[kennygti 0]

I bought a PTS cam of mattbenselin on here. Im planning to run that along with webers in my 1900 so any feedback from people currently running this spec engine or any pointers would be an advantage for us both. Mine isn't for rally just abusing people on country roads

[Baz 421]

Sounds pretty similar to an engine i want to build, 1600 ona budget with fairly std internals with work to the head, 285 cam and a set of bodies. Only will echo what andychalmers said in the fact that you don't want to be pushing the power band too far up, a 285 or so profile cam with carbs/TB's along with a shorter FD, 4.4 or so shouldn't be too bad IMO, as it's predominantly a tarmac car especially. 150bhp is a nice figure to aim for, if a little optimistic on a budget without major re-working though.

Edited April 16, 2009 by Baz

[Saveit 0]

COuldnt you throw a 16v head from say an mi16 on the 1600 bottom to match the S1600 engines? Those are 16v only they are TU.

[welshpug 1,661]

I think a 225 bhp TU5J4 is a bit OTT for a newbie to the rally scene

 

they're not cheap either, £££££...

[stuart 31 3 Cars]

COuldnt you throw a 16v head from say an mi16 on the 1600 bottom to match the S1600 engines? Those are 16v only they are TU.

 

I've read about a couple that have been done before but I think it'd be too costly for my budget, custom pistons are needed at least along with a lot of machining / setting up to get them to run properly.

 

 

So it sounds like a 285 profile cam is the one to go for then.

 

Just one more question though - will I gain anything by getting rid of the injection with one? I would get a mappable ignition if I did by the way.

 

I've read a couple of posts recently on here and the 205 cup forum by people that have not got the improvements they hoped. Also, I fitted webbers to my old Xs and I think it was actually slower than before but drank fuel like it was going out of fashion.

It's the sound I want really, to hell with my carbon footprint! Lol.

Edited April 16, 2009 by stuart

[welshpug 1,661]

I've read about a couple that have been done before but I think it'd be too costly for my budget, custom pistons are needed at least along with a lot of machining / setting up to get them to run properly.

 

 

So it sounds like a 285 profile cam is the one to go for then.

 

Just one more question though - will I gain anything by getting rid of the injection with one? I would get a mappable ignition if I did by the way.

 

I've read a couple of posts recently on here and the 205 cup forum by people that have not got the improvements they hoped. Also, I fitted webbers to my old Xs and I think it was actually slower than before but drank fuel like it was going out of fashion.

It's the sound I want really, to hell with my carbon footprint! Lol.

 

 

IMO, that's an excellent thing to do, especially if you are going for cam upgrades, they'll give great drivability when setup properly which is exactly what's needed.

[James_R 3]

282 catcam v std 1600 cam

 

[j_turnell 137 3 Cars]

 

Std 1.6

 

 

Pugsport Group A max torque cam

[James_R 3]

wow that's some serious engine bling PTS make