can you install roller without headwork

[ek02]

From what I remember, .420 lift at the valve is the most you can run without cutting the guides.

 

[Wahoo]

By 'sounding mean' do you mean loping like a V8 with too much cam? If so, don't bother. Those types of cams really don't belong in a street car.

Well I don't expect it to sound that loopy but a little to make it sound like a more aggressive cam is in there.

I understand NA engines and forced induction engine require different cam profiles, and forced induction dont really need a wide lobe separation... Correct? Or if not ill have to edit this post. Don't want to spread incorrect information.

 

[we4Mateo]

From what I remember, .420 lift at the valve is the most you can run without cutting the guides.

I was wondering when. I'm sure every car is different, but that's a good rule of thumb. Is there a set amount that can be cut off the top and be safe even if it's more than needed? I'm wondering bc I'd rather have my machine shop just take off a little extra when the do the valve seals for the exhaust guides and be done with it rather than mock it all up, but I'll do what's needed.

Also, my current exhaust guides are in good shape on my new heads I'm working. Do I NEED to do exhaust seals when going roller?

 

[earlbrown]

From what I remember, .420 lift at the valve is the most you can run without cutting the guides.

That's an overly simplistic statement. There are factors that using that rule could mess you up. The amount the retainer hangs down toward the guide isn't a fixed distance in all occasions. A set of keepers that moved the retainers down .050" for example, would cost you .050" of available room. A non stock retainer that's thicker, a thicker than normal seal, new seats that move the valve down into the combustion chamber, etc...

Accurate rule of thumb: measure, measure, measure.... then measure again. Then cut if you have to. Lowering guides is really no big deal. Hell, you can buy a drill motor powered cutter than will top the guides in much less time than it takes to post about it.

When it comes to valvetrains, there's always a good change you can get away with SWAGing it... but there's also a VERY good chance that SWAG won't be right. With the amount of damage a shoddy valvetrain can do to our cars, there's really no reason to just start throwing parts on it.


As for the muscle car lope... what you need is a cam with lobes that are too fat, and lots of overlap. That way the vacuum signal at idle is so shitty, the car has that choppy lopey idle that triggers our pituitary gland and makes us dream of big HP.... The problem is overlap blows boost and unburned gasoline right out the exhaust pipe. Big fat lobes kill off dynamic compression and has to either have high compression pistons (or make up for it with boost...that goes right out the tailpipe). Basically the car becomes a dog, with crappy gas mileage, crappy bottom end, long spool up time, and makes peak HP at 10,000 on an engine that can't turn more than 6000ish... oh, and the vavletrain will most likely be unstable and have a limited lifespan.

Even fire V6's don't naturally want to lope like a V8 anyways, so it's that much harder too.


I will admit my car does have a bit of a lope to it.. Not a 'steet freaks' lope, but it doesn't sound like a 6. It does have too much cam in it for what I have, but it was a free roller so I ran it (plus I cut my own guides down to match the .500+ lifts and increased the compession to 9:1). If I had a smaller roller it would already be in the engine.

 

[Wahoo]

You have to remove the heads to cut down the guides correct?

How perfectly square do the guides have to be?

 

[earlbrown]

yes, the valves have to be out of the way for the tool's pilot to locate in the guide. By design it's not possible to cut them (correctly with the correct tool) out of square. I guess a hacksaw blade or hand held grinder could make them out of square. I guess it really wouldn't matter as long as the seal was installed square. Ohterwise the opening would go oval.

 

[Wahoo]

Basically needs to be done at a machine shop?

Not one of those DIY type of jobs.

 

[pacecarta]

w

 

[kidglok]

with the right tool ( $64 from summit) it could be done on a bench with a hand drill,
the cutter tool is self aligning through the valve stem hole and just guide it down
you need to remove the valves (big C-clamp type spring remover) and you really should replace the exhaust valves with smooth stem valves so that you can run seals
but if the head is off why stop there
while head is off might as well get the valves cleaned and reseated and install the new seals and springs
and while the valves are out would be a good time to clean up the guide protrusions from inside the pocket and smooth out the radius
and might as well grind the sides of the pedestils down for roller rocker clearance

i have the comp 212/212 in my 87X (ported prepped irons) . reality is the 212/212 can and has run 9s but it is a mild cam that if i didnt tell you i had it in there you wouldnt even know from stock

And if going thru all that trouble might as well buy a set of champion irons. Fwiw I went 9.92 on Alky with a 212/212, PAC 1201 springs and 1.55 rockers on champion irons.

 

[ek02]

Basically needs to be done at a machine shop?

Not one of those DIY type of jobs.

If you buy the tool, have a slow speed drill, and can take the heads apart, you can do it. The diameter of the cutting tool must match the size of the seals. As Earl said, you have to take all measurements into consideration when figuring how much to cut the guides down. The .420 I posted was for a stock engine as it came from the factory. The retainers and locks being used and the amount the valves may have been sunk in the heads by previous valve jobs all affect the measurement. I like at least .060 retainer to seal clearance at full lift.

 

[Wahoo]

I wish I knew this before I bought the cam kit. I don't want to rip the heads off unless I have a problem like blowing a head gasket.

Guess ill have to try to sell it then.

Unless its such a pain in the ass to do valve springs with the heads on the car, because I know I need to replace those either way

 

[earlbrown]

Valve springs on the car is actually easier than most people make them out to be. It won't be 'perfect' without a height mic and a spring tester.... but, over the decades there's been enough trial and error shotgunning that make that job close enough (plus you don't have to be perfect to be leaps and boundds better than stock springs)