Bad Lifter 305 what to replace?

[kcackler]

I am very green when it comes to engine work, but I have narrowed my engine trouble down to a worn lifter and have read I need to replace the cam as well.

What other parts do I absolutely have to replace when I replace the cam?
What parts should I replace/inspect while I am doing this?

How do I determine what parts will work with my engine?

Truck is a 77 C10 with 305 and is mainly used for light hauling and just getting from A to B.

There are a couple pictures of the bad lifter.

[Dead Parrot]

Cams and lifters should be replaced as a set. While things are out, check the push rods for straightness. Possible the cam bearings will need replacing.

You well need fresh gaskets for all parts and covers removed. And gasket sealant.

Consider a new timing chain/gear set. Good time to inspect the balancer.

[kcackler]

Thanks for the info and the confirmation!

How do I inspect the balancer and the cam bearings?

I will have access to a boroscope for the cam bearings if that will work but what am I looking for specifically?

How do I know/figure out which components (New Cam/Lifters/harmonic balancer/timing chain gear set/possibly rods and rockers?) will work with my specific engine? Or is it as simple as just buying a cam and lifters that say they work with a 305?

[Willshook]

Cam and lifters for sure. Inspect the lifter bores for uneven wear. Might as well replace the timing set "while you're in there", especially if there's any slack in the chain or if the cam gear is plastic.

This type of failure opens up the valve clearance, so inspect everything - rocker arms, pushrods, etc. with a particular focus to ensure the tops of the valves aren't damaged.

I wouldn't be overly worried about any bearings; you certainly have particulate in the engine, but it'll either wash out in a few rapid (500 mile) oil/filter changes or there's damage and you have a bigger issue. Don't borrow trouble.

As for what to use, a mild CompCams 4x4 is my usual recommendation for a mild SBC. If you can provide some details on the heads and the rest of the engine I can give you a few suggestions to think about. A 305 is Just Another Gen I SBC

[kcackler]

Thank you for the info!

Okay I will remove all the rockers and push rods and lifters tonight and post more pictures for more discerning eyes.

As far as additional info on the engine, I was told that it came out of a 70s model Nova after there were issues with the original if that is helpful at all.

I can look at the heads tonight, should there be a part number stamped into the metal?

[ochremo]

I would call CompCams or your cam of choice and tell them what you have and what you are going to do with it and let them recommend a cam. I'd also consider a roller cam as they are much more forgiving without having to be concerned about breaking in a flat tappet cam. The cam company can sell you everything you need as a kit if you choose to do that. Like Willshook said I wouldn't be overly concerned with the cam bearings especially if you had plenty of oil pressure.

[kcackler]

This engine is old and has I don’t know how many miles on it, with the roller cams/lifters being more expensive would you still put that style into it?

[ochremo]

Yes personally I would as there's been so many issues with flat tappet cams and lifters lately. There's a process to breaking in a flat tappet cam and also special oil needs to be used which isn't a big deal especially since you'll need to drain it right away after the new cam break anyway. Not because of breaking in the new cam necessarily but because of the bad lifter and cam lobe putting particles in the engine prior. I wouldn't have suggested this several years ago but I would today. Nothing worse than spending the time getting everything put back together just right and having to tear it back apart.

[kcackler]

Okay good to know thank you!

[Dead Parrot]

Is this a long term engine or a 'Get By' motor while a better one is built/found/bought? If it is a Get By repair, then less is probably better. You can go down a very expensive rabbit hole on a tired motor and still have a mostly tired motor.

[Willshook]

There are zero issues with a flat-tappet cam if properly broken in and the right oil, which is readily available, is used.

A retrofit roller is a significant expense and effort for zero value on such a mild engine.

Worn cam bearing don't present as low oil pressure.

[kcackler]

Originally Posted by Dead Parrot

Is this a long term engine or a 'Get By' motor while a better one is built/found/bought? If it is a Get By repair, then less is probably better. You can go down a very expensive rabbit hole on a tired motor and still have a mostly tired motor.

100% this is a get by engine as I don’t have a reliable history other than the limited I have done to it. That being said I want to be able to use every bit of life I can out of this one within reason.

[Willshook]

Given the engine size and usage, you're likely best off with a stock/replacement cam - there's really no choices I found looking at the CompCams that would be a good fit, other than the old "929" cam which would be workable.

https://www.compcams.com/factory-mus...all-block.html

There are certainly other choices out there.

[kcackler]

Originally Posted by Willshook

Given the engine size and usage, you're likely best off with a stock/replacement cam - there's really no choices I found looking at the CompCams that would be a good fit, other than the old "929" cam which would be workable.

https://www.compcams.com/factory-mus...all-block.html

There are certainly other choices out there.

Okay, thanks for that.
So this would be close to factory replacement of my current cam?, any recommendations on lifters?

Do I need to get any information off old cam to be sure this is a viable option?

[Willshook]

Originally Posted by kcackler

Okay, thanks for that.
So this would be close to factory replacement of my current cam?, any recommendations on lifters?

Do I need to get any information off old cam to be sure this is a viable option?

Pretty close to the original; this was the baseline GM cam for a long, long time. You could probably get it from a standard parts place, but Comp is a far better product than a lot of parts store-type engine parts. The springs are probably tired and a little light, but you're not going to be beating on this thing, right?

For lifters, they'll be listed on that same link. Don't spend the money on hardened lifters - it's a good idea with the high performance, near-roller ramps, but this is pretty mild.

https://www.compcams.com/high-energy...big-block.html

There's a timing set there too - I personally use Cloyes in everything, but the CompCams set is certainly a quality piece. Make sure you use new ARP bolts and their tab retainer for them.

Anything around .400 lift or so will work. Just don't end up with some high-performance, high-RPM cam because somebody told you it'll make a bunch of power If you're an experienced engine guy, you could consider installing the cam 4 degrees advanced to move the power curve down...but that's for expert builders only. You can certainly fill out CompCams recommendation form...but I would warn you that I ALWAYS find their recommendations too aggressive - they assume you want to make big power.

Finally, break this in right and use the right oil. If you have questions about the process happy to give mine, and there are tons of online resources. I have yet to lose a flat-tappet cam after building 100's of engines with them.

This is a pretty straightforward proces, just take your time and do it all right

[kcackler]

No I will definitely not be beating on it lol.

I am definitely not an experienced engine guy if you couldn’t tell, this is the first one I have worked on and I am just learning as I go.

Are these the ARP bolts you are talking about?I don’t think so because I don’t see anything about a retaining clip. https://arp-bolts.mobi/?src=redirect...p?RecordID=228

Do I have to take off the heads to replace springs? Would you replace these in my shoes?

If so could you link it please

For the timing set would this be acceptable https://www.compcams.com/high-energy...5-91-sbc.html?

I appreciate all the help with this.

[Willshook]

Take a good look through the cam swap videos online until you have a feel for what's needed. The single biggest risk here is setting the cold valve lash...so if you don't know how to do that - get someone experienced to help. No faster way to wipe a cam.

Here's the CompCams version; might as well stick to a brand:

https://www.compcams.com/lock-plate-...8-w-bolts.html

I wouldn't remove the heads, and I wouldn't bother changing the springs. The exception to this is if you find a rocker arm has been beating the heck out of a valve tip...then we're into having some cylinder head work done and it's time to consider options. I think your intent here is a repair, not an upgrade, unless we find a Problem. When doing these types of repair, if the engine was running well otherwise the less stuff we touch the less likely we are to CAUSE a Problem. The most expensive words in mechanic-land are "while we're in there..."

That timing set is fine as a stock/replacement; the more expensive ones are rollers, which is nice when making more power, and have keyway for advancing/retarding cam timing.

Don’t forget this stuff:

https://www.compcams.com/cam-lifter-...tle.html?gQT=1

https://www.compcams.com/br40-conven...ak-in-oil.html

No worries; you've got this and I'm sure you can get everything sorted out.

[kcackler]

Awesome I am gonna order this stuff today and continue my disassembly, I will update with some more pictures of what I pull off and the tops of the valves tonight.

My intent is definitely to repair until it is time to replace.

Never set the valve lash before but I have been watching videos past couple days when I figured I would need to. It looked somewhat straightforward.
Thank you for all the links!

I appreciate the faith lol updates to come!

[geezer#99]

The first thing I recommend for a newbie builder is buy some literature like this.


https://www.ebay.ca/itm/176869322730...SABEgIVqvD_BwE

[kcackler]

I couldn’t get that link to open for me.

Update: I removed the rockers ,rods, lifters, water pump, and radiator before I ran out of time (my light died and I couldn’t see lol). The rods were straight, the rockers all looked the same with no crazy amount of wear, and the lifter holes all seemed fine as well to me nothing too crazy. Here are some pictures of the lifter bore holes and the tops of the valves.

[geezer#99]

Linky no worky eh!
Just google ‘how to rebuild your small block Chevy’.
Bunch of choices should pop up.

[kcackler]

Originally Posted by geezer#99

Linky no worky eh!
Just google ‘how to rebuild your small block Chevy’.
Bunch of choices should pop up.

Hahaha okay will do

[Grounded63]

If you have an accurate way of measuring the cam lobes (dial indicator) I would check the lobe with the bad lifter. If it measures to spec. Just replace the bad lifter. Assuming you really only have a single lifter with an issue. And the rest of the engine is in relatively good shape.

If you want to reuse a cam and lifter set you are required to keep the lifters in the correct order. Preferred.

If you do not keep the lifters in order. You have to replace all the lifters with new. Assuming all cam lobes are in good condition. Acceptable

A new cam gets new lifters. Obviously.

[kcackler]

Originally Posted by Grounded63

If you have an accurate way of measuring the cam lobes (dial indicator) I would check the lobe with the bad lifter. If it measures to spec. Just replace the bad lifter. Assuming you really only have a single lifter with an issue. And the rest of the engine is in relatively good shape.

If you want to reuse a cam and lifter set you are required to keep the lifters in the correct order. Preferred.

If you do not keep the lifters in order. You have to replace all the lifters with new. Assuming all cam lobes are in good condition. Acceptable

A new cam gets new lifters. Obviously.

The worst one by far is the one in the picture, but I can send in more pictures of the rest later. Yes I kept everything separate just in case. I assumed with how much was gone from that one the safest course would be to replace the lifters and cam.

[Willshook]

Do not reuse that cam or any of the lifters. Period.

Ain't going to go back-and-forth with anyone, but that's just a hard no.