Has anyone ever done a cam swap?

"Bandit" (2bandit)
08/09/2013 at 10:49 • Filed to: question, emma

Any tips (even the most basic) and links to useful guides would be appreciated. I'm wanting a better cam for my 400.

DISCUSSION (20)

The WB > Bandit
08/09/2013 at 10:53

What car/engine? That will impact the complexity a lot.

GasolineLollipop > Bandit
08/09/2013 at 10:56

These guys can probably point you in the right direction http://www.jbp-pontiac.com/index.html

Bandit > The WB
08/09/2013 at 10:57

It is a 1974 Pontiac 400. It's not currently in the car, and I have a cam picked out. This is how the engine sits:

Kinja'd!!!

Sparf > Bandit
08/09/2013 at 10:57

I'd imagine it's the same as with an SBC. Have you tried Googling for guides?

This looks helpful and so does this .

For Sweden > Bandit
08/09/2013 at 10:57

Pushrod engine, right?

Might as well do a complete engine rebuild while you're in there.

Bandit > For Sweden
08/09/2013 at 10:59

Yep, I don't have the money for a full rebuild.

Bandit > GasolineLollipop
08/09/2013 at 10:59

Thanks!

Bandit > Sparf
08/09/2013 at 10:59

I have not looked up SBC guides, thanks!

For Sweden > Bandit
08/09/2013 at 11:00

Then get a job, ya bum.

Arch Duke Maxyenko, Shit Talk Extraordinaire > Bandit
08/09/2013 at 11:01

If you got money here's the Horsepower build.

Bandit > For Sweden
08/09/2013 at 11:02

I have one! I work 8 hrs a day!

Sparf > Bandit
08/09/2013 at 11:02

I found those two links by Googling "Pontiac 400 cam install" though. It's really just about being careful as you slowly insert the cam (which you should lube properly with the oil that should come packaged with the camshaft) into the block.

For Sweden > Bandit
08/09/2013 at 11:03

That's 16 hours a day you're not working!

GasolineLollipop > Bandit
08/09/2013 at 11:09

NP. Cam swap on that engine I'd recommend having the cam bearings replaced by a machine shop. New bearings, cam, lifters. Pushrods and rockers should be replaced too. Insert cam slowly and don't nick the bearings putting it in. Break it in and you are off to the races.

LandSpeed-DSM > Bandit
08/09/2013 at 11:14

Tips on the cam? Or tips on the install? Both would require more detail on your setup, application and goals.

Bandit > LandSpeed-DSM
08/09/2013 at 11:17

install.

desertdog5051 > Bandit
08/09/2013 at 11:23

Done a couple.

Best advice I can give is follow the manufacturers details. Should be able to get them from the guy you bought the thing from or online.

The Swedish Bandit > Bandit
08/09/2013 at 11:30

You've got a Haynes manual, right? Cause you'll find all the basics in there. Otherwise it's pretty straightforward, remove the old cam and insert the new one. Also inspect the cam bearings while the cam is out, if they look bad you're going to have to replace them. Either by having a machine shop do it for you (which takes time and is expensive, but it gets done right), or by buying or fabricating a tool to remove them yourself, which is riskier but cheaper and faster.

Also if you're going for a substantially more aggressive cam, you are gonna want to make sure you have adjustable nuts for the rocker arms from what I've heard.

If you have any more specific questions, ask away, since I've basically done the exact same swap.

The WB > Bandit
08/09/2013 at 14:54

Oh, piece of cake then. Make sure you get a new set of lifters with it, and inspect your cam bearings. You'll most likely want to replace them. I haven't done a Poncho motor before, but they're all pretty much the same except for the retention under the timing cover.

If your bearings look good you may not have to replace them, but probably you'll need to. You can either get a good set of micrometers with a good plunger probe or just replace the bearings with a bearing press set.

If you ever remove a flat tappet cam with the intent to reinstall it again, be sure you know which lifter goes with which lobe. If you don't put them back in the order they came out you're likely to wipe a lobe because they wear into a pattern with each other.

So knock out the bearings with an installation tool (including the rear freeze plug, put the new ones in, install your new freeze plug, put in the new cam, drop in your lifters, and button everything up. Be sure to coat the cam and lifters with assembly and break-in lube. Another good idea is to use a drill motor to spin the oil pump by itself and build pressure before you try to start it.

If you go any larger with the cam you'll need to check your piston to valve clearance and be sure your valve springs can handle the lift and ramp speeds.

Flat tappet cams are finicky to break in, make sure you get it to fire quickly, then keep it idling for 20 minutes at 1500-2000 RPM. After that run it for another 30 minutes at low load and varying RPMs to make sure it's broken in well. High zinc oils like Brad Penn and certain Valvoline racing oils (or the no-longer-produced GM EOS) can help out on the wear problems at breakin, because reformulated common motor oils have cut the flat-tappet critical ZDDP additive out almost completely.

I run Brad Penn in my Mustang all the time, but a lot of people don't run it after initial break in and have no problems.

A Pontiac blueprinting book would always be a good investment, it will detail the procedure for putting it in for your motor specifically.

Bandit > The WB
08/09/2013 at 15:06

Thanks for the tips! I'm just about to remove the harmonic balancer.