Performance Cams and Valves

[RRoller123]

If that is the 274FI, I will vouch for that.

Pete

[DrivesLikeFoust]

I recently purchased some 40-80/80-40 cams from vick auto and I’m curious if anyone has run these before? Not sure what to expect and I’m hoping I won’t loose any power. I am doing a port polish, free flow exhaust and high compression pistons to help but I would like some more information on these cams if possible.

[baltobernie]

What fuel delivery method are you using? I can tell you that those cams, pistons and exhaust with decent carburetion produce decent power on an 1800. Can't comment on Bosch or other EFI intake. You should use adjustable cam wheels to ensure that the cams are degreed-in.

Read up on port polishing and matching. Many say it is unnecessary and even counterproductive.

[DrivesLikeFoust]

Its an FI 2L. What exactly is done with the cam wheels to improve the camshafts? I am doing the work myself so I would need to know exactly how to set them. And oh thanks for the tip I will look into that.

[Nut124]

If you plan on using adjustable cam pulleys, then you must be prepared to "degree" the cams yourself. Otherwise the adjustable pulleys are just trouble.

The bigger cams may allow the engine to extend the power curve another 500-750 rpm making another 10HP or so at max RPM at the expense of some low Rpm driveability. Mid-rpm power may stay unchanged if you are lucky. Unless you rev the engine to 6500+, not much to gain. Any gains depend on the fuel delivery being able to keep up. Bigger valves, cams add power by shifting the operating range higher up in the rpm range. HP = Torq x RPM. So if you can maintain the same torque at 10% higher rpm, you have 10% more HP.

What do you have for a header? Hotter cams work best with a header with long primaries or at least long 4-2-1 secondaries.

IMHO, white smoke is not valve guides. It is likely a leaky head gasket.

[DrivesLikeFoust]

Ah okay. I don’t have plans to race the car or do anything too sporty but just to pull some more power out of it. The cam pulleys can wait until further down the road. Thanks for the advice though. My header is hopefully going to be vicks 4-2-1 header unless they can’t get them in stock. Otherwise I may use the ricambi header which I think is similar.

[baltobernie]

What exactly is done with the cam wheels to improve the camshafts?

They don't "improve" the camshafts, they ensure that the valves open and close at exactly the correct point of engine rotation. You attach a degree wheel to the crank pulley, usually with a piece of sticky clay, and fashion a temporary pointer, usually a piece of wire. Using a dial indicator, you find TDC, and bend the pointer to the 0° mark. Then, using the specs shipped with the cams, you adjust the exhaust and intake wheels so that #1 valves are fully open at, for example, 40°. As you go "up" in tune, there is less room for error.

If you're not changing your fuel system, the 40/80 cams are not worth the expense, IMO. A stock FI two-liter in perfect tune is a nice performer. I spent thousands of dollars rebuilding my 1800 to performance specs, and it produces about 120 HP, approximately the same as a good 2L. And if you don't take the trouble to get everything matched and correct, you might end up with less oomph.

[JohnMc]

Has anyone done a YouTube on tuning in the adjustable cams specifically for the 124?
If not, could someone do one sometime. I would presume that many more would be sold if one could really see how it is done.
Just a thought.

[DrivesLikeFoust]

Thats makes more sense. Thanks for the info. I’ll take a deeper look at those adjustable wheels. And I agree, a video would be extremely helpful.

[Nut124]

This is a pretty good tutorial - not twin cam by the principles apply.

http://www.lunatipower.com/Tech/Cams/Ho ... eACam.aspx