Mi16, S16, And Mi16x4 Standard Cam Differences

[Anthony 1,000]

As per the title really - does anyone know how the Mi16 (XU9J4), S16 (XU10J4) and Mi16x4 (XU9J4) camshafts differ in terms of lift, duration, and profile? I believe that Mi16x4 cams have slightly longer duration than the standard Mi16 cams, but how do the S16 ones compare?

 

I've got a set of each of the above spare, along with both #2 and #4 pulleys, and need some cams to run for the time being on my new engine until I can afford/justify some proper cams and verniers for it.

 

Rough spec of it is 2045cc (86x88) S16 bottom end running somewhere in the region of 11:1-11.2:1 compression, S16 head with 3-angle seats and tidied/flowed inlets, possibly Maniflow 4-2-1 manifold (if I can get it to fit without fouling - otherwise standard S16 cast item), DTA management and Jenvey throttle bodies

 

Basically, out of the above cams (Mi16, S16, Mi16x4) and pulleys (#2's and #4's) what's the best combination for a decent spread of power and driveability?

[Anthony 1,000]

Actually, thinking about it I have a pair of unused Kent PT1601 (262 degree) regrinds here as well that I guess I could use - although I was going to sell them and put the proceeds towards something that'll make the most out of the engine.

[Sandy 189]

The regrinds might be a good idea, with the increase in capacity you're getting, the standard cams will probably peak quite low, around 6200rpm.

[petert 554]

The Mi16x4 has a few more degrees duration, but the same lift as the other two. From memory it's around 262 deg.

[maxi 36 1 Cars]

Anthony you really really need to run some lairy cams to get the most out of your engine build. You have the first element of what is really needed to make one of these engines sing.....compression. The second ingredient is large cams.

 

Sell the regrinds, forget std cams and save a few pennies for the long trip to QEP! You know you need pussy power under the bonnet

 

Maxi

[Anthony 1,000]

Sounds like Mi16x4 cams might be the way to go then - reckon a #2 or #4 pulley is best with them for spread of power?

 

Anthony you really really need to run some lairy cams to get the most out of your engine build. You have the first element of what is really needed to make one of these engines sing.....compression. The second ingredient is large cams.

 

Sell the regrinds, forget std cams and save a few pennies for the long trip to QEP! You know you need pussy power under the bonnet

It'll be getting some more manly cams in the future, but right now I'm in the middle of buying a house and hence my spare cash is kind of tied up in that.

 

The standard cams are a temporary measure to get the engine in the car and running, and I'll sort something better in the new year. Besides, I've been driving around in 8v's for so long that the engine even on standard cams is going to feel somewhat rapid - I've been Mi-less for best part of 18 months now!

[Dazza 4]

My common sense given your nearing house purchase say's either fit the 262's and run the engine in for awhile ,or buy the 275 inlet cat cam and in the future get the 285 inlet and switch them around on verniers .

you might have to watch the valve clearances given the stroke your running and optimum timing may be a problem due to this compramise .

You could however just fit standard cams and carefully run it in sensibly .........but you dont want that i bet !!!!! ha ha ,me neither .

Dazza

[petert 554]

You'll have bags of torque, so I'd just use the Mi16x4 inlet with a #2 pulley.

[maxi 36 1 Cars]

The only downfall I was thinking is that if you change the cams/spec of the engine at all, it will have to be mapped again. There are a lot of people that fool themselfs into thinking they can self map their cars with very little experience. Some things are left to the professionals and with the camshaft change at a later date will mean a trip back to them.

 

Maxi

[James_R 3]

You could however just fit standard cams and carefully run it in sensibly .........but you dont want that i bet !!!!! ha ha ,me neither .

Dazza

 

It's already been sensibley run in, so that's nothing to worry about luckily

 

I've been Mi-less for best part of 18 months now!

 

Mincing!!

[pug_life 0]

no anthony you have 4+ engines sat around so you can't class yourself as mi-less

[Anthony 1,000]

Thanks for the replies

 

You'll have bags of torque, so I'd just use the Mi16x4 inlet with a #2 pulley.

I'll take your advice on that one - guess a #4 pulley will make the dynamic compression a little high as well considering the highish static compression (considering it's on standand pistons) and standard cams?

 

The only downfall I was thinking is that if you change the cams/spec of the engine at all, it will have to be mapped again. There are a lot of people that fool themselfs into thinking they can self map their cars with very little experience. Some things are left to the professionals and with the camshaft change at a later date will mean a trip back to them.

I know what you mean, and hence I'm going to wait until the engine is built to the spec I want before getting it professionally mapped. Until then, I've got a couple of base maps that should get it running, and between myself and James_R (who's mapped a few ECU's now) I'm sure we can tidy the map enough that whilst it might not be achieving its maximum potential, it'll be fairly quick and enjoyable

 

no anthony you have 4+ engines sat around so you can't class yourself as mi-less

Engines that aren't installed in cars aren't much fun - can only stand by them and make "bwwaarrppp" noises so much