Exhaust-to-Intake cam swap

[baltobernie]

Any reason why an exhaust cam cannot be used on the intake side? They seem to be identical except for the disty gear, which wouldn't interfere with anything on the intake cam box.

I'm considering a set of 40/80 performance cams, and am hedging my bet. If this set is too strong for my taste, I could replace the performance exhaust cam with the OEM, then sell it here for somebody else's intake usage.

[racydave]

Aren"t the cam gears different? And I've heard both ways, some say to use a adjustable cam gear, some not. I might be interested in the other cam, let me know later? Gee no answers, but more questions... This comes close to a post a few years ago. Bernie, have you modified your head, and are you running stock pistons?

[htchevyii]

Jon Logan, (midwest124.com) says it will work just fine, he does it all the time.

[So Cal Mark]

this is a poor solution to a motor that has been over-cammed. No one is happy with a motor with too much cam, they just don't run very well. You're so much better off with a little less lift/overlap then a little too much.

[ventura ace]

As you can see in this picture of a 1438cc cylinder head, the intake and exhaust camshafts are the same. Look at the orientation of the first lobe (straight up) and the pulley allignment dowel (straight down) for both camshafts.



The magic is in the clocking of the camshaft pulleys. You can see in this picture of the intake and exhaust camshaft pulleys that the index hole is oriented differently in relation to the camshaft dowel hole.



How do you like my new paint job, BTW?

Alvon

[So Cal Mark]

Mike Bouse won't like it

[mbouse]

I wouldn't go that far Mark. It is a nice looking paint job. Could have been better, and not too late to change.

takes a special person to fully appreciate the beauty of KRACKLE paint!

[baltobernie]

Bernie, have you modified your head, and are you running stock pistons?

Complete engine rebuild, with 10:1 pistons, cylinder head prep per Croft video, disty recurved and converted to Pertronix, 38 DGS carb on port-matched 1800 manifold, low-restriction exhaust. Csaba and the guys at IAP say this is the right cam for Sunday Driving. It looks like I have two fallback options if low-end performance is unacceptable; adjustable pulleys or the reinstallation of the OEM exhaust cam. Mark, if you have any cam vendor suggestions, I'd like to hear them. The others I've seen are European, and $500-700 for two iron sticks is obscene, IMHO.

Denise, Alvon, one thing's for sure ... there's another early Spider in the lead pack
... and Mike, I've got something to please you, too.

[ventura ace]

I wouldn't go that far Mark. It is a nice looking paint job. Could have been better, and not too late to change.

takes a special person to fully appreciate the beauty of KRACKLE paint!

I think you're talking about the cylinder head. I was talking about the blue hood that the cam pulleys are resting on.

Or, maybe you were talking about the hood. Krackle hood?? I wouldn't have to try to keep it polished then, would I? Maybe I could use some of the cottage cheese stuff that they used to put on ceilings!

Anyway, back to the original point. It's my understanding that the clocking of cam lobes and camshaft index dowel is the same for all the camshafts, intake and exhaust. And different valve phasing is accomplished by how the cam pulley is indexed. Apparently, different cam pulleys have been made through the years with slightly different indexing (according to what Jason Miller has found by studying a lot of camshaft pulleys). You get the most flexibility by using adjustable cam pulleys, but then you'll need to adjust them to where you want them (not just plug and play).

A

[mdrburchette]

I don't think a 40/80 cam is very aggessive. I'm running 42/82s in my 1608 with 9.8:1 comp and 40 IDFs. I say go for it and I'll race you up the hill at the next Freakout!

[baltobernie]

You're on! But you gotta add a hundred pounds of ballast to make it fair

[ventura ace]

I don't think a 40/80 cam is very aggessive. I'm running 42/82s in my 1608 with 9.8:1 comp and 40 IDFs. I say go for it and I'll race you up the hill at the next Freakout!

You need me to lead the way?? I hope you don't fall off the road like you almost did last time. Good thing you had a second time around for practice!

Alvon

[mdrburchette]

I didn't almost run off the road...I almost flipped out of the car when it was sitting at a 90 degree angle. Okay, we'll make it a competition during the autocross event. I can't fall off then.

[brad131a4]

Delta Cams in Tacoma WA can make you what you want for a very reasonable price. I think that they even have some blanks for fiats to make them with. I know they had some about ten yrs ago but can't guaranty they still do.http://www.deltacam.com[