TKOPerformance wrote:

Was it a carbed engine or EFI?  I'd have less hesitation about just dropping in an EFI engine, as they wear the cylinders a lot less than a carbed engine does.  You can check for a ridge at the top of the cylinders, but I've yet to ever see an engine that had a noticeable one, whether the rings were shot or not.  A lot of guys go by the "I can still see the crosshatch", which is also bunk.  I've never not seen crosshatch in a cylinder.  Actually, a freshly honed cylinder has almost no crosshatch in it.  The crosshatch shows up from wear, not from machining. 

You could always just dingle ball hone it and slap a set of rings on the pistons.  You're assuming that the bore doesn't have much taper or out of round if you go this way, but if you're right you'll get good ring seal. 

Skunkape:  I have a scratch hone and honing oil you can borrow if you go that route.
 

My question fits along this same vane. My 289 runs perfect.  It was a freshly rebuilt stock C code when I bought the car 10 years ago. I think the cam holds my current set-up back. I would like to upgrade to a custom ground cam which matches the existing components of my 66 289, but does not exceed them. I would do the cam swap with the motor in the car. Or should I leave the 289 alone and find a roller 5.0 and build a second engine. I can build the engine, it would be a really fun project, but I am limited on funds and time.

Last edited by ponyboy66 (11/16/2015 7:22 PM)

ponyboy66 wrote:

My question fits along this same vane. My 289 runs perfect.  It was a freshly rebuilt stock C code when I bought the car 10 years ago. I think the cam holds my current set-up back. I would like to upgrade to a custom ground cam which matches the existing components of my 66 289, but does not exceed them. I would do the cam swap with the motor in the car. Or should I leave the 289 alone and find a roller 5.0 and build a second engine. I can build the engine, it would be a really fun project, but I am limited on funds and time.

Thats easy go to comp cams use their cam calculator talk to 'em about what you want (stay away from changin' valve springs if you can order the kit with lifters get a good set of fel-pro gaskets two cases of your favorite beverage and a long weekend. parts, geegaws, and doodads shouldn't exceed 500 bucks, but if you got extra cash go roller , Me I'm cheap 

ponyboy66 wrote:

My question fits along this same vane. My 289 runs perfect.  It was a freshly rebuilt stock C code when I bought the car 10 years ago. I think the cam holds my current set-up back. I would like to upgrade to a custom ground cam which matches the existing components of my 66 289, but does not exceed them. I would do the cam swap with the motor in the car. Or should I leave the 289 alone and find a roller 5.0 and build a second engine. I can build the engine, it would be a really fun project, but I am limited on funds and time.

You DEFINITELY need to change valve springs and timing chain set if you swap cams.  The old springs have seen millions of compression cycles to a certain height.  If you add a cam with higher lift, the springs will get stressed in a different position and will ultimately break, dropping a valve and destroying the engine.  Of course, this begs that you will also need screw-in studs to keep the stronger springs from pulling the studs out of the heads.  A cam change, while it seems to be an easy upgrade, can lead to a serious case of WYAIT and you might as well increase the compression to take advantage of the cam, so a total rebuild is in order.

The roller 5.00 is the way to go...

The thing to remember, as MS alludes, is that engines are systems.  One magic part doesn't make a commuter engine into a race engine.  You can improve flow on the exhaust side and intake side to a point and see some modest gains.  You can add a more aggressive cam that improves flow even through a set of lackluster heads, but all to a point.  If you've ever seen any Super Stock racing you'll see where it goes if you go to far.  Those guys can't port their heads, let alone use aftermarket castings.  They are limited to stock compression, stock manifolds, and stock cam lift.  Where they can get creative is duration and lobe separation.  Those engines idle at like 2,000RPM, and make big power at the top of the powerband.  They would make a terrible street engine.  Those guys do what they have to in order to make the most power they can under the rules of their class, and that's all those engines are good for.

A street engine has to be a jack of all trades.  It operates over a very wide RPM range.  So building power in a street engine needs to be done such that its well rounded.  A complete system where cam, heads, intake, exhaust, compression, and induction are matched makes the best well rounded combination.  So you get into a bit of chicken and egg with modifying a street engine.  40-50 year old hardware responds better to single mods than newer engines do, but don't expect that a cam swap is going to take you from 200HP to 400HP.  A nice top end system with good exhaust may take you from 200HP to close to 400HP though, but not on a 289 unless you really want to zing it. 

I had to make that decision too.  I'm still running my 289 for now.  I decided I'd rather have a stick in the car and take care of some other stuff first.  I've got a 5.0 based 347 shortblock on an engine stand that will eventually find its way into the engine bay, but for now I'm going to enjoy the car and its greater usability thanks to the OD I'm getting with the T5.