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Have heads off: Roller rockers?

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Old 02-26-2003 | 07:09 AM
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From: MA, USA
Car: 83 bird
Engine: 305/383
Transmission: WC T5
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Have heads off: Roller rockers?

Ok, I know it seems like all I post is; "How can I make my car faster?" but I really know nothing about engines, just how to remove them, take 'em apart, and throw them back together! I mean, I know how they work and all, but if you asked me what the #'s on a cam meant, or what is needed to take a 350 to the 383 stroker level, I'd be clueless. Sorry for the ignorance, but how else do you learn?
<p>
Well, I was wondering about my valvetrain... (right word, right?) I have my heads off right now for valve seals, and was wondering if roller rockers are worth it. They seem to run $150-$250 and new heads are way too expensive. Are they worth it, and what ones are good? Any other mods I might make while I'm in there/ going to have to make to use them? One last thing, do they install just as the stock ones, and have to be adjusted and all the same, or is it like a Mopar (oh please) where you bolt them on and no fiddling is required!!!
Old 02-26-2003 | 09:00 AM
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Valve lashing

I can't answer your question about whether or not roller rockers will help your HP, but if you DO replace your rockers, you'll need to do the valve lashing. You don't just bolt your rockers on until the nut is all the way tight. It has to be tightened to the right spot. It's not too hard to do. I have the 350 TPI in my GTA. I'm sure your motor is the same. Basically, what you do, is remove the #1 spark plug, and put your finger over the hole. Turn the crankshaft until you feel pressure building up in the #1 cylinder. Keep turning the crankshaft until the timing mark on the vibration dampener lines up with the 0 degrees timing mark. Your #1 cylinder will be at top dead center. Then you adjust 4 of the intake valves, and 4 of the exhaust valves. I can't remember which ones it is at the moment, but I could look it up. Anyways, what you do, is tighten the nut on the rocker down and twist on the pushrod until you can feel a little resistance. Then you tighten it down 3/4 of a turn and you're done! Once you get the first 8 valves adjusted, you turn the crankshaft another 360 degrees and line the timing mark up again. Now your #6 cylinder will be at Top dead center. You adjust the other 8 valves the same way and you're done! It's really not as complicated as it sounds. Don't forget to put your spark plug back in! Matt
Old 02-26-2003 | 10:07 AM
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Ed Maher's Avatar
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From: Manassas VA
Car: 04 GTO
Engine: LS1
Transmission: M12 T56
Wow. You took the heads off just to do valve seals? Do you drop the oil pan to change the oil too?

Roller rockers aren't a big power adder, but some 1.6 full rollers can be worth 10-15hp if you're very lucky. They are a direct replacement for teh stock rockers, so you don't need the heads off to put them in. And yes they need to be adjusted just like stockers. And you should be GLAD they are adjustable, non-adjustable valvetrains can be a real headache to set up if everything isn't perfect.

Here's a thought if you have later heads that need self aligning rockers. Get them machined for screw in studs and guideplates. Then you can run cheaper non-self aligning rockers. Of courese, you'll spend as much on the machining as the price differential, but at least you can reuse the rockers if you go to aftermarket haeads later.
Old 02-26-2003 | 02:52 PM
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Engine: 305/383
Transmission: WC T5
Axle/Gears: 3:42
Well, I wanted to put on chrome valve covers, then I saw the rockers and said, hey maybe I'll replace them! I figured I'd do the seals while I was in there, and replace the head gaskets, as it has 165k miles and my coolant has been dissapperaing.....
Old 02-26-2003 | 02:53 PM
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Not everyone has an air compressor. No air compressor, no changing valve seals with the heads on.
Old 02-26-2003 | 03:27 PM
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From: Manassas VA
Car: 04 GTO
Engine: LS1
Transmission: M12 T56
Originally posted by Brian'sIROC
Not everyone has an air compressor. No air compressor, no changing valve seals with the heads on.
I would never use an air compressor to do it on the car anyway. 2 much better and easier ways are available:
-The dead easiest is to simply bring the cylinder you are workin on to TDC and go to town. With the piston at TDC the valve cannot fall down far enough to even matter.
-If that makes you nervous, take out the spark plug and thread some rope into the hole, then bring the cylinder up to as close to TDC as possible. The rope will completely fill the gap and the valves will not move at all.

Using a compressor is too risky IMO. If you accidentally knock the fitting off, or loose pressure for some other reason then you are for sure pulling a head (because the piston will be at BDC when you pressurize it, so the valve will be gone.) The methods above cannot possibly fail unless you forget to move the piston.
Old 02-26-2003 | 03:46 PM
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I certainly wouldn't put rope in my cylinder! What if it broke off in there or something? Again, you would be pulling a head! If you're losing antifreeze, I would make sure you're not leaking somewhere else. Check your oil and make sure you don't have any in there. If you do, then you'll need to change the head gaskets, and flush the oil system. Antifreeze in your oil can corrode bearings. Then you'll wish you were never born if you have to fix it yourself, or pay somebody to do it! Matt
Old 02-26-2003 | 04:22 PM
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bigals87z28's Avatar
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From: Ocean, NJ
Car: Check The Sig
just dont keep fillin it up and up without checking what is going on... look what can happen
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Old 02-26-2003 | 05:14 PM
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Ed Maher's Avatar
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From: Manassas VA
Car: 04 GTO
Engine: LS1
Transmission: M12 T56
Why would the rope break off in there? Thats like saying you're afraid to use a funnel to fill your oil, because it might break apart and fall inside your valve cover. It just doesn't make any sense as a possibility.
Or perhaps you didn't understand it was implied that you leave some rope hanging out so you can pull it out. Also goes without saying that you don't pull the rope out until you back off the cylinder. I thought those 2 were pretty obvious steps though.
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