Webcam's in a 3.0 rebuild

The Donkey · 12-05-2006, 04:30 PM

I am looking at doing a rebuild on a 3.0 and am looking for a few modifications to increase the power just a bit. I hear from one source that you should use webcams to increase the power and from another source that you shouldn't because the engine will run rough forever, idle improperly, etc.

Which opinion is correct for the general consensus?

Thanks.

tadd · 12-05-2006, 05:24 PM

It doesn't matter who makes them, just how the lobes are ground. First question for a 3.0 is what fueling system you are using. I assume CIS? If so you need almost zero overlap since 'back flow' upsets the fuel metering mechanism. If you change to carbs, like PMOs, then you can have lots more overlap and thus more options are possible. I play in the small engine box, so I have not dealt with the CIS problem personally. I am sure there are solutions. If you are doing a top end overhaul, you could switch to euro pistons, PMOs and a more spicy cam like a mod S. That would put some zing in your 3L.

tadd

john walker's workshop · 12-05-2006, 05:52 PM

webcam 20/21 cams work fine. smooth idle, passes emissions and improves throtte response quite nicely.

911 tweaks · 12-06-2006, 03:33 PM

Hi John-

If you do this cam, do you need to change/update any of the valves, springs or associated items??
Thanks, Bob

Boxer 6 · 12-06-2006, 06:27 PM

Get a hold of John Dougherty at "Dougherty Racing Cams".

tech 1 · 12-13-2006, 05:52 PM

Web Cam is a great choice! as well is Elgin. and yes you should change the valve springs! Aasco,Elgin are a couple we use in the shop.Both Elgin and Web offer a 964 clone, perfect choice for a 3.0 cis motor.Obviously you are doing a valve job.Right? Now for the technical stuff.....CHECK V.O.T.C. (valve over top center) clearance.I have 3.0 apart right now and all the exhaust valves kissed the pistons.It has 964 cams in it.More than likely it's a product aggressive downshifting,but this proves the theory that it should be checked on every engine!! Bump the comp. for more power also.Euro P&Cs or JE pistons.However you are somewhat limited on what you can do with C.I.S.While I'm thinking about it ,you need to do that valve check in more than one position,not just at t.d.c. Remember the valve actually chaces the piston down the bore.Allow .060" intake and .100" exhaust and you'll never go wrong! Tim.

LeeH · 12-13-2006, 06:14 PM

My '82 3.0L has 20/21 grind Web cams. It ran great... right up until I downshifted to 2nd instead of upshifting to 4th at a DE.

Tim - when you say "change the valve spring" are you talking new springs or stronger springs?

tech 1 · 12-13-2006, 06:26 PM

Lee, I'm saying both!!! But please reread the part I wrote about valve clearance! It is extremely important and not hard to do.It might be covered in Wayne's book,I'm not sure,but if you have any questions you could call me at my shop in the morning and I could walk you through it! (760)873-8923 It sounds like you might have done some valve damage already.Tim.

LeeH · 12-13-2006, 07:50 PM

Tim - We're still working on getting my engine apart so I can send the heads off the the machine shop. When it comes time to reassemble everything I'm sure I'll have some questions. I've read the section in Wayne's book several times. It will probably make more sense once I'm actually doing the procedure.

Jeff Alton · 12-13-2006, 09:29 PM

I use John (camginder on this forum) for all my cams. I have built a couple of 3.0 with 964 cams and it makes a nice motor. With a 964 cam the springs *may* not be required, it is a pretty mild cam in the big scheme of things. Yes, measure the valve clearance, and it is covered in Wayne's book too. There is a couple of ways to do it, but Tim gives good advice to check at more than TDC.

Cheers