Installing a performer 400 intake and eddy AVS 650cfm carb. I'm going to install an edelbrock chain and gears straight up and eliminate the .5 degree retard out.

How will it run? better? Am I making a mistake keeping the stiock cam? Or will this help overall?


Thanks!~

 

Generally speaking, if your cam bearings are in good shape, this would be a good time to install a cam/lifters since it's disassembled as far as it is.

Magazines like to say stuff like "Hey, stab in a new cam and gain 30hp" but like to leave out the nasty bits like getting varnished-up lifters out and pushrod specs, rocker arm geometry, and sealing the whole business up again only to wipe-out a cam lobe and having to do it all over again.

I would say "YES", now is a great time to change your cam...just be aware that in real life it doesn't go as simply as it does for the magazine and TV guys...they tend to leave out the shi**y parts...gotta SELL stuff.

 

The mistake in keeping the old cam is that:

1. You don't know what shape it's in...pull a lifter or two and check its foot for convex (bad) or concave (good). That'll tell you what shape the cam is in also. Old, worn valve springs could be a consideration, too.

2. New cams have a 4* advance ground in, the old ones don't. So changing the just the cam timing (chain/gears) will yield minimal (if any) increases in torque and HP. It's your choice, of course, but check the lifters before deciding on cams/valve springs/retainers/keepers.

With the Edelbrock carb....a good idea is to get a fuel pressure regulator and inline gauge. They don't like more than 5.5 - 6 psi and Ford pumps put out around 7 - 8 psi.

 

Hey, F-Beast...can you expand on this a little bit?

"New cams have a 4* advance ground in, the old ones don't. So changing the just the cam timing (chain/gears) will yield minimal (if any) increases in torque and HP. It's your choice, of course, but check the lifters before deciding on cams/valve springs/retainers/keepers."

I've always installed new cams based on the cam card and put in new timing sets "straight-up" (that's assuming a relatively mild "street" cam). I like to think that I'm a little bit savvy when it comes to modern cams in old engines, but I was unaware of this little factoid. Is this based on LSA or base circle? How does it effect cam phasing and rocker geometry?

 

Jonnyyuma: Yuppers, setting the cam timing on a new cam is always (my preference, too) "straight up" which gives you about 4* advanced as is. If you have a hog wild, holy shoot! type of cam, that another ball game...as in do you want more top end=go more advanced....more low grunt = retard it. Then there's the discretionary discourse on manifold or ported vacuum advance with a mad cam....hehe

If you remember the new cams/timing gears, they have 3 choices for cam timing - 4*(?) advanced (giving you a total of 8* advanced cam timing), straight up (4* advanced) and 4* retarded. Your choice depending on the cam grind.

Cam phasing - unlike todays vehicles with variable valve timing - in my simple mind (?) is setting cam timing advanced, straight up or retarded.

Valve train geometry is a function of the pushrod lenght, valve spring shims (or ground out spring seats) for height, etc....not so much needed with stock stamped steel rockers.

This "4* advance ground in" is a function of the ICL....and nothing to do with the LSA. ICL + ECL divided by 2 = LSA. When you have the LSA (After you use a degree wheel to find the ICL), other cam events can be found. Your cam card has the ICL on it, as I'm sure you know.

I know your got yer **** together......

End Highjack?

 

It's an out of warranty Jasper motor with only 3000 miles on it. Runs fine, except absolutely no *****, and the EGR keeps burning carb spacer gaskets and creating nasty exhaust leaks. Hence the EGR free intake and carb swap. I'm no stranger to cam swaps on these things, and peeking under the valve cover, everything is clean, shiny and freshly machined. If I can pick up a few ponies by setting the gears to both points facing each other without disturbing the valve springs, cam, lifters and lash then I'm a happy guy. However, if this action will not realize any potential gains, then I will do the swap, Either a competitive 252DEH or an efelbrock performer camshaft. I'm honestly hoping to not have to.

 

Which brings me back to my original question: Can I swap a better carb and intake and run the original cam?

 

Filthy beast, thank you for the well thought out replies.

 

I think you have a good plan starting with a pretty fresh reman engine in good shape. It should help. Also, the 400 is touchy about valve springs. Putting more than a stock cam with stock springs is asking for a big problem.

It is hard to know exactly what springs Jasper used but likely stock spec. If you put more cam in it is a really good idea to replace the springs to match the cam. Better (and safer and cheaper) would be to use the current cam and springs IMO.

Are you planning anything with exhaust ? (duals or headers + duals). That would help breathing and power with the upgraded induction.

 

Yes sir, I've got duals on it now with manifolds. As time and money will allow, headers will come eventually.

 

Chances are the cam is already installed straight up, it has been a long time since the three position timing gears came out for the 400/351M. I don't know how Jasper installs the cam on these engines though.

Fifteen years ago or so I bought the Edelbrock cam and lifters, intake and carb kit. I put the intake and carb on my truck and immediately went from 8mpg to 11, 12+ on the highway. This was with a stockish cam from when the engine was rebuilt by the previous owner, (Yes I got the paperwork that said he had spent over $2700 on it when I bought it in 1998).

The reason I said stockish is that he lived in California and had to get it smogged. I was active duty so I registered it in my home state and didn't have to keep it looking stock, plus I had transferred out of CA by the time I put the four barrel on.

Robert

 

A better 4v intake and carb will get you a better breathing engine, even more so with headers. Those alone would give you a few extra horsies. The new intake, as you know, dumps the EGR making her (my opinion) a better breathing animal. So, yes, by all means swing with the setup you want and leave the cam alone....for now.

With so little miles on her (the cam/lifters, cam/rod, main berrins, etc should show little signs of wear), I would suggest to run her with the new intake/carb and see how you like it....seat of the pants type of deal, as opposed to the old set up. You can always change things down the road...

You're welcome! Actually, I make all this stuff up as I go.....

 

Interesting stuff here. I may be picking up a 4v intake later on today...one of my hillbilly buddies (of whom I am immensely jealous) says he knows a cat w a small stash of em. We'll see how the old 360 likes it and then move on to cam selection...maybe.

 

One thing most people don’t consider is the non-egr manifold doesn’t get nearly as hot as the egr manifold with that exhaust flowing through it. This almost eliminate heat soak in the carb and improves performance. Also if you are going to put a new chain on it definitely install a double roller. They are a good investment. Also I must be old school. I didn’t know about putting the 4 degrees into cams now days.

 

Good point and very true.

Just peek at the cam card - if, for example, the ICL is 108* ADTC and the LSA is 112* you know you have 4* advance ground in with an ECL of 116* BTDC. No advance ground in would have an ICL of 112 and an LSA of 112.

Without degreeing the cam it could be off a few degrees either way. The cam people don't always grind it to specs....you find out what they are or how close they are by degreeing it. Of which, I'm sure you're aware.