Catcam Mi16 Inlet Cam

[d-9 0]

Now my 309 is halfway to having the handling sorted, ive been playing with the performance a little, it feels flat as hell below 5000rpm, absolutly no go at all, and pulls better when it comes on cam, but probably nothing like as much as I hoped. Has anyone else got a catcam inlet cam and had problems like this?

 

Its a 1.9mi16, 2row mi16 management, manifold reangled with a qep plate, magnex exhaust and catcam 4900526 inlet cam, think its running no2 pulleys on both the inlet and exhaust cams.

 

Currently feels a LOT slower than standard, the 106 has noticibly more midrange go.

[huxley309 0]

try retarding the cam a bit if your using a vernier did this with mine and it improved low/mid end because with the valve opening sooner it has the chance to pull more air in and with it closing sooner reduces the chance of inlet reversion

[welshpug 1,651]

yup, have a play with the cam timing, what does the cam have over the std one?

[Anthony 1,002]

As I said, it feels to me like the cam timing is out by a few degrees - certainly it feels *very* flat and gutless below 5000rpm, and subjectively doesn't feel any quicker than standard above that.

 

It drives and feels exactly like Kate's engine did with the same cam when that had the cam timing a few degrees out...

[inferno 1]

jackherer has just change a 2,2 cam pulley set up on another car to 2 zorst 4 inlet... and was a significant performance difference... not sure if it would achieve the same with that cam though.

[d-9 0]

Playing with the cam timing is a serious effort, as it involves getting a dialgauge, verniers, and potentially rolling road time, especially as if the figures petert posted are correct, the no2 pulley puts it slap bang in the range suggested by catcams.

 

Any ideas if i can tweak it by just adjusting both tensioners?

Edited September 21, 2006 by d-9

[John_B 11]

Mine's always felt great- but then I've never driven a standard one. taffycrook who's driven loads was very impressed. It's standard apart from slight head work and 3 angle seats- no vernier. Oh, and the downpipe split had melted and blocked off some of the pipe.

 

Here's the graph:

 

[Anthony 1,002]

Playing with the cam timing is a serious effort, as it involves getting a dialgauge, verniers, and potentially rolling road time, especially as if the figures petert posted are correct, the no2 pulley puts it slap bang in the range suggested by catcams.

 

Any ideas if i can tweak it by just adjusting both tensioners?

Stop being a lazy bar-steward and check it, as you're certainly not getting the most out of that engine as it stands! Atleast check that all the cam timing holes line up if you're sticking with standard pulleys, and prehaps try a #4 pulley on the inlet as that should help restore some mid-range.

 

You can screw the cam timing up very easily by adjusting the tensioners wrong....

[petert 583]

think its running no2 pulleys on both the inlet and exhaust cams.

 

This is your problem. The inlet cam is far too retarded. It needs to be advanced. As said, fit either a #4 or a vernier, so the lobe centre is 106-108 degrees.

[d-9 0]

After a bit of a read on the catcams website, Ive realised ive got it wrong, the 112° wasnt the recommended timing, its the "peak angle".

 

Specs of the cam are as follows, any further advice would be welcome, but i'll probably fit a no4 pulley at the weekend

 

4900526INTAKE

clearance [cl] 0.00mm

duration [0.1mm+cl] 275°

duration [1.0mm+cl] 237°

valve lift [cl=0] 10.80mm

peak angle 112°

followers: O.E.M.

timing [1.0mm+cl] 7/50°

[welshpug 1,651]

forgive me for sounding daft but what are these "No2 and No4" pulleys that are mentioned?

 

Wouldnt a vernier be such a simple tool to use? i.e weak cam, run it on dyno, tweak a little more and do another run?

 

seeing as its a simple allen key to loosen and tunr?

[d-9 0]

No2 and No4 are the different cam pulleys that are fitted to the various mi16s as standard, no4 runs more advance than no2.

 

A vernier would be preferable (but more expensive as currently im loath to spend yet more money on a car that has done nothing but disappoint), but i'd need a dial gauge to make sure i got it on in the right place and didnt have a valve meets piston incident, and then rolling road time at £cha-ching/hour to get it setup.

Edited September 21, 2006 by d-9

[dee205 3]

What kind of power would you expect from the setup compared to standard? And compared with both Catcam inlet and exhaust cam?

[James_R 3]

I have a 4 pulley knocking about the shed if you need to borrow one to see if it's any better Mr Doug

[d-9 0]

cheers james, I *think* ive got one in the shed, but ive been operating a fairly relaxed storage policy in there recently (open door, throw in crap, close door), so i may take you up on that offer!

[sorr 0]

Oddly I had this same debate is it the number 2 or 4 pulley. Phoned Matt at QEP and he believies it to be use number 2 on the exhuast and 4 on the inlet.

 

Doug - I have a spare number 4 pulley also if I am closer than James.

[Dazza 4]

The inlet Cat-Cam is giving an impressive 17 bhp over standard ,ive looked at these for a while now ,did you know these will also go on the exhaust side aided by vernier pully when you want an even bigger inlet cam ! how goods that and at £220 ish there not bad at all .

i intend going for both cat -cams with my Mi16 build for the 205 ..

Dazza

[maxi 36 1 Cars]

Doug as has been said, you need the no.2 and no.4 pulleys. Mine was exactly like this with regrinds on the last engine when the pulleys were fitted the wrong way around. Id also say your cam timing is out. get in there mate, rip the belt off, put the pulleys in and time it up. Couple of hours with scraped knuckles and it will shunt.

 

Maxi

[jackherer 543]

I agree with the above, you need the right pulleys, I changed a 2.0 Mi16 running 1.9 Mi16 management from two no. 2 pulleys to a 4 on the inlet and its much better to drive.

 

BTW I took the head off my mates (as far as we know) standard Mi16 recently and it had no. 4 pulleys on both cams! It went very well on that setup, but its going back together with an inlet catcam and the head is with Mattsav at the moment for a recon and I'm not sure which pulleys to put it back together with (I have 2s and 4s to choose from). I'll probably go for 2 on the exhaust and 4 on the inlet as its known to work but what effect would people expect a 4 on the exhaust to have?

[cybernck 402 1 Cars]

has anyone compared #3 DFW pulley with #2 and #4 on the same engine?

[petert 583]

has anyone compared #3 DFW pulley with #2 and #4 on the same engine?

 

yes, just in case you're too lazy to search the old topics.

 

#2 - 114 deg. lobe centre angle

#3 - 111 deg.

#4 - 108 deg.

 

The effect is quite pronounced. Just like fitting a vernier pulley!

 

I always use a #3 with one of my Stage I cams and sometimes an offset key as well, to give a total of 108 degrees. Bigger cams such as my Stage II grind need to be run at aorund 106 degrees. However, you'll need to check valve to piston clearances if you run a reasonable cam at this centre. Any cam bigger than standard should be dialled in at 110 deg. as a starting point.

 

If you start messing around with deck heights and thinner head gaskets, checking the timing is a must, as there often isn't enough take up on the inlet cam belt tensioner. So you need to pull more tension on the exhaust tensioner, the result of which retards the cam timing.

Edited September 24, 2006 by petert

[cybernck 402 1 Cars]

yes, just in case you're too lazy to search the old topics.

i know that, i've even posted some info and diagrams myself .

 

i was asking if anyone has practically compared them on the same engine.

 

so it's worth fitting #4 pulley even to an otherwise standard DFW engine?

 

and have you experimented with retarding/advancing the exhaust cam?

 

thanks.

[d-9 0]

Well ive fitted the no4 pulley and its a lot better, its actually driveable below 5000 now! Still doesnt feel massivly fast, but its not bad.

[petert 583]

so it's worth fitting #4 pulley even to an otherwise standard DFW engine?

 

definitely. They go a lot better at 108 deg. than 111.

[d-9 0]

Have you ever tried a no4 on the exhaust?