Utahcarguy

So, I've owned my '61 Fuelie for about a month and already she is trying my patience with 3 major issues involving ripping apart the engine compartment. If you have been following along, you know that my #2 cylinder was not operating as the lifters pushed themselves out of their respective holes and were sitting in the valley. I thought this was due to faulty rocker nuts, so I replaced them on all 16 rockers and set the valve lash for the supposed solid lifers my car is supposed to have.

After a 2 hour drive this past weekend, I lost major power in the engine and it was time to take off the valve covers again and see what is going on. Here is what I found.

The #2 and #8 cylinders had broken rockers and the lifters were in the valley once again, this time with a new friend...a bent and broken push rod. Now, I set the valve lash to .015 for intake and .018 for exhaust (cold). This is what was recommended for the solid lifters I am supposed to have.

I decided to take the #2 cylinder lifters apart. One had a springiness to it (not a good sign). Turns out both lifters had springs in them, one with oil and one without (the springy one had no oil). So, this means someone swapped out the solid lifters with hydraulic lifters!

Now I'm at the point where I am not confident what comprises my top end. Here is what my plan is and where I need help. I am thinking of installing a new cam, lifters, rockers, and push rods. While I'm at it, I might as well replace the timing chain. Anything else I should swap out while I'm in there?

This car is a drivers car. I will be driving it every couple days until Winter hits in October. So the cam needs to be street-able. However, I don't want to feel like I am driving a grandma car. This is a sports car after all.

With that in mind, do you have any recommendations on which cam to buy for this Chevy 283 SB?

I was thinking of going with roller rockers as they are easier on the valves and considered higher performance. What do you think?

Do they make high performance hydraulic lifters that will be less maintenance and quieter than the solid lifters yet still offer great performance?

1COOL60

I'm sure you will get a ton of suggestions on what cam to use, so I will start.

If you want a solid lifter cam I would suggest the Duntov 097 cam. This is the solid lifter cam that would have come with your engine originally. For a hydraulic lifter cam, I would consider the 350 HP 327 cam, also known as the "151" cam (those are the last three digits of the part number). Others may suggest after market equipment.

By all means, whatever you select, install new lifters and pushrods. Roller rockers will be fine, but you may have to change valve covers as the poly locks will probably not clear the original valve covers, unless you have after market heads.

You also need to install new valve springs, and check for coil bind. Your problem kind of sounds like you are getting coil bind, thus bending pushrods. Do you know what cam is in there now? Sounds like it has a lot of lift (non-factory) and the valve springs are not correctly matched to the cam.

You might also consider screw-in rocker arm studs; press-in studs can pull out if you have a lot of valve spring pressure.

Good luck, and keep us posted.
160

Powershift

I was just about to post the exact same words/advice.

Larry

Utahcarguy

Thank you for your suggestions. I'll get new valve springs too. About the lifters, does someone make high performance hydraulic lifters? Quieter and less maintenance than solid?

I do not know what cam is in there now, that is one reason I am changing it. I want to keep the stock valve covers to maintain an original look, so maybe roller rockers are out???

1COOL60

Rhoades (spelling?) makes hi-performance hydraulic lifters that bleed down at lower rpm's, that is supposed to give a little more bottom-end with a long-duration hydraulic cam. However, they almost sound like solids. I have used them, and didn't think they were of much benefit. If you go with a hydraulic lifter cam, you should be okay with stock lifters to, maybe, 5500 rpm (that may be a stretch). You could also consider some after market anti-pump up hydraulic lifters for a few more revs.

Although I don't know who makes them, there are spacers that you can use to raise your valve covers to clear the roller rocker poly locks. Actually, I did find some spacers at Summit Racing:

http://www.summitracing.com/parts/st...make/chevrolet

160

Texaspilot180

Probably not the advice you want to hear, but having been down a similar path with my 65 FI recently I would pull the engine and deliver it to a reputable engine shop to tear it down and inspect everything and then make sure all is done properly. In my case had a bad vibration we couldn't find, and eventually pulled the engine thinking it was a flywheel or pressure plate issue but was convinced by a local shop (reputable Corvette place) to look inside the engine and when we did found the last builder (who was supposed to build it to OEM specs) did a very bad job, with nothing balanced or weight matched, mismatched pistons, had three bad lifters, bad cam (incorrect cam not even close to what his build sheet claimed was put in) etc. I should have been more involved in the initial engine build but the shop should have done what they were asked and paid to do. Get the engine out and get it done right, then put it back and move on, you will be glad you did.

Utahcarguy

My engine revs to 6500 RPM.

AZDoug

You can always zero lash hyd lifters so they won't pump up at higher RPM.

You back off each lifter when car is running, until you hear clatter, then tighten just past no clatter about 1/8 turn.

I did that on my L82 cammed L79, and it would run to 7K RPM.

Doug

Powershift

I think this is "extreme" at this point………….but I would pull the heads and check them along with changing the cam, lifters, springs, rockers, pushrods, and timing chain. This way you know what you have, and you can check the springs for coil bind as well as make certain the valves and valve guides are good.

Sounds like the OP has a hydraulic cam and lifters, and was setting them as solids. This is sure to produce a lot of "bad things/dynamics" with the pushrods and rocker arms.

I guess the OP could also drop the pan and check things from below……at least look for obvious issues. But unless he has other issues that he hasn't reported, I would not take the block apart at this stage.

Larry

Powershift

But not consistently at this point.

Unless you really know what was and wasn't done to this engine in the past, I wouldn't push it beyond about 6000 RPM. If you want to go higher in RPM, then MAKE CERTAIN what you have in the block, crank, rods, and pistons.

Larry

MikeM

I would replace what you have with OEM replacment valve train parts sold by Speed Pro/Federal Mogul. The replacement 097 camshaft, rockers, pushrods, springs and lifters. That cam with stock springs will run past 7000 rpm. Alternate to the above is the replacement OEM 151 camshaft which is hydraulic lifter and has a nice lope to it and still pulls hard past 5500. You don't need/want hi performance lifters.

As mentioned above, your valve springs may be coil binding or someone just stuck some very stiff valve springs in your engine.

If you go with the above factory replacement parts, no need to go with screw in studs if they haven't pulled any and you don't need the roller rockers.

If the timing chain isn't stretched or isn't a cheap replacement, no need to replace it either.

PS. If you really do have hydraulic lifters in that engine and you are pushing it past 6000, you could possibly/likely be pumping the llifters, experiencing valve float and doing that valve train damage with your heavy right foot.

JohnZ

The kind of damage I see in that photo of the rockers with their guts torn out says you either have severe coil bind, WAY too stiff springs, piston-to-valve contact when your hydraulic lifters pump-up, or some combination of the above.

If it was mine, I'd tear it down, find out what's REALLY inside it, inspect it, and put it back together with the correct OEM-level parts it's supposed to have, and not worry about it any more, but that's just me. With the right parts, it'll run forever.

Utahcarguy

What is coil bind?

Ironcross

apparently this happened more than once...I would suggest taking a course in valve lash, especially if you don't know coil bind ...Perhaps EOI and ICE will provide the best and easiest method to adjust valves....I read only a month or two of ownership;;;from your pictures if I`m reading your pictures correctly and they are not FI exhaust manifolds...and not all FI Vettes were equipped with solid lifter engines., not many but still a FI Vette...I would do some checking as it may not be a true FI Vette

Stay away from the fancy stuff, GM parts are tough to beat......

856666

follow this link

http://www.cranecams.com/faqview.php?s_id=21

Frankie the Fink

Pretty much agree with all the above - find out what you have and go OEM as much as you can. My 270hp 283ci with solid lifters and 097 Duntov can and stock rockers will sing well into the 6,500 RPM zone - no problem. Those valve cover spacers to add roller rockers look like cr@p on a vintage engine IMO - that's not gonna fix your issues in any case. I think JohnZ pretty much covered the possible causes in his post above.

Easy Rhino

May or may not be extreme to take the entire down to parade rest. Here's my argument (I'm sure the OP may not want to hear it). Unless the OP knows that whoever did the cam and valve train mess was limited only to the engine top end, they could be risking the entire engine.

If the engine is solid, few parts (gaskets) will require replacing, and it is a simple tear down, spec it out and rebuild.

If, on the other hand the engine was as badly done as the cam and top end, you might save the engine and a fortune. If the same guy did the engine as did the top end I would not hesitate to tear it down to parade rest. I'm no full-time mechanic, but the crap I've seen Bubba do would make your hair stand on end. How about non-graded fasteners, like all-thread, in place of con rod bolts?

Good luck.

Powershift

The further along we go with this thread, the more I tend to agree. I made this comment early on.

However, it is possible the the cam and lifters were actually fine, but the new owner thought the hydraulic cam was a solid Duntov cam and set it like that. This excessive (open) lash on a hydraulic lifter cam and lifters will cause issues, as the hydraulic cam does not have the clearance ramps to easily take up the valve lash like a solids cam. Especially is the hydraulic cam is a "high perf racing type"…..and the new owner runs the RPM up to redline. The hydraulic cam installer or engine builder also may never have checked for coil bind.

I earlier recommended dropping the pan in addition to pulling the heads, but stopped short of recommending a full engine teardown……..unless the owner wants frequent 6500 RPM operation/performance. If he does, then he needs to make sure everything in the engine is up to spec. That requires a full teardown, and that is his decision to make. I stated that in Post #10.

Larry

Utahcarguy

So the engine is out! Turns out #8 had a stuck lifter and it was completely domed on the bottom, so I'm sure the cam is shot. As I took things apart on the engine, I noticed the passenger side manifold was cracked (same side as all my engine issues). I was told this might mean I have a burnt valve. We took the heads off and the valves and cylinders look good. The comment from my automotive engineer friend was that it looks like the engine was recently rebuilt and looked good. I have the "double hump heads" and screw in rocker arm posts.

We will pull the cam tonight and see what we find. Looks like a top end only rebuild

I'm hoping the stuck lifter caused the cam to go bad and that is the cause of all my issues. Now to find out why the lifter got stuck....

Vet65te

You mentioned that you might only have to do a top-end rebuild but with all the damage we're seeing to the valvetrain parts, you really should consider disassembling the entire engine. You've done all the grunge work for the removal, now that everything is exposed this is the time to go ahead and put new bearings and seals throughout and not have to guess as to their condition or that it 'might' have been rebuilt recently. I know the heavy duty 8" damper didn't arrive till '62 for the high horse engines and that the 61 dampers were a bit smaller but that's another area you could double check now and if the elastomer band between the two rings looks seriously cracked or not completely intact, send it to a place like Damper Dudes and have them freshen it up.
Mike T.