defaced

iTrader: (6)

Hey guys, may sound like a stupid question but here it goes.

I just put a rebuilt 350 in my Formula, it's just a stock engine with stock heads and everything. I'm looking at getting some roller rockers to throw in there. When the engine was rebuilt they didn't install new rockers, just reused the old ones and I'm getting a lot of noise from them. Plus I figured some roller rockers will help free things up a little bit.

My question is, is there a standard size for these stock heads? Pretty sure the engine is an 86. Not sure what it came out of though. I'm finding 1.5 and 1.6 ratio, what does that number mean exactly?

watajob

iTrader: (29)

That is the ratio of the rocker lift. 1.6 will give you more lift at the valve although they may cause an interference problem where the push rod comes up through the head.

ninetyone

iTrader: (2)

you will need self-aligning type rockers.

Vader

That's close, but not quite correct. If the engine is an '86 the old standard non self-aligning rockers should be used since the push rods are guided by the slots in the heads. '87+ used self-aligning. My '86 was one of the last ones to come out of Van Nuys in July and still used the old heads.

Another thing to check is pushrod clearance at the guides. With a non-stock rocker the guide holes may need to be elongated slightly to clear the pushrod in the open or closed valve positions. I got lucky on mine and was able to just bolt down the 1.6 Crane roller tips.

Drac0nic

Dare I point out he said he put "a" rebuilt 350 into his car, not that he put the original back in. Do you have any idea of what year it is? That would influence your decision for align vs. non-self align as mentioned. Besides that, if you have clanking you probably need to check your lash. There's a chance you've got 1 or 2 loose or something like that.

-AO-

Does the engine have centerbolt valve covers?

defaced

iTrader: (6)

Yes

And I'm not "exactly" sure what year it is. I thought it was an 86 but when MGM asked me if it had centerbolt heads, I realized that those weren't used until 87. So, hell, it could be an 87 or later. I do know for a fact that it is not a roller block.

Edit: I bought the long block off a guy at work. Unfortunately, he didn't know anything about the engine.

Vader

If the heads are centerbolt (good question, MGM) they will require either self-aligning rockers or guide plates (never both). That would eliminate the heads being from '86 or before.

ninetyone

iTrader: (2)

Pull a valve cover and get the casting number off of the drivers side head. Try to get some casting numbers off the block too. How do you know its not roller.

defaced

iTrader: (6)

Because when I bought the engine from my buddy at work, I brought it home and took it apart. Wanted to take it to the machine shop in pieces because it would be less work for them. They also reconfirmed for me that it was not a roller block.

ninetyone

iTrader: (2)

what heads are on it then?

grumpyvette

before Id even think about swapping rockers id suggest find out why
"When the engine was rebuilt they didn't install new rockers, just reused the old ones and I'm getting a lot of noise from them. "
it could be they are simply adjusted wrong, but a burnt rocker ball, or a wearing cam lobe are surely potential reasons also, once youve determined the current problems source and corrected it , THEN proceed with the rocker swap

defaced

iTrader: (6)

You make a very good point. I'm leaning more towards they're just not adjusted right or just need tightened. I'm praying that there's nothing wrong with the cam, there shouldn't be because it's a brand new cam with only 5k on it and the engine.

Thank you guys, this is what I needed. I think I'm going to swing my upgrade choices in some different directions and go with the rockers a little down the road. I'm going to take your guys' advice and take the valve covers off and inspect the rockers that are already in there.

Thanks again.

Irockz

iTrader: (1)

I'd be willing to wager that you would receive little to no gratification from a swap to roller rockers alone.
I'm with the crowd,identify the source of your noise,and work from there,the cost of a good set of roller rockers can be better spent elsewhere on a mild engine.

As far as the cam being "brand new",if the proper camshaft break in procedures weren't followed,it might as well be 50 years old.
Oil today is junk,if there wasn't a break in additive and a 20 minute cam break in upon initial firing of the engine,that would be the first place I would look.

defaced

iTrader: (6)

I'm not too worried about the cam being bad. I can assure you that the proper cam break in period was done because I'm the one that did it. I fortunately had a lot of help from a good buddy of mine that has done this a few times. And yes, I did add the break in additive. The shop that rebuilt the engine gave it to me for free, just to make sure I didn't forget about it. I told them it was my first time rebuilding a motor so they helped me out a little bit.

InfernalVortex

iTrader: (4)

Id still worry about losing a lobe. I was super paranoid with mine and it lived a harsh life early on - but I still worry one day it will just get in a mood, and some of the lobes will go on vacation...

You can do a quick visual check by seeing if they all move about the same with the engine idling with the valve covers off.

You need to set valve lash correctly anyway, may as well let it idle for a minute without the covers and get a visual before you go around setting lash. Jiggle the rod up and down to feel when the slack is taken out of it. Rotating it works too, but if everything is oiled, it can be hard to tell. You just want to get it to zero lash, where the lifter spring isnt compressed and there's no slack in the rocker arm. Then give it a half turn - should be set properly forever. It's up to you where you want to do the half at 180 degree intervals method or the EOIC method.