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I dropped a lifter in my olds 350. I pulled the intake and pulled the lifter out and the bottom of the lifter was smoked but I stuck a bore scope down the lifter bore and the cam looks ok I think. I also stuck my finger down there and ran my fingernail along the lobe to see if it would catch anything and it didn’t. So now I’m gonna replace all these lifters but my question is what lifter do I choose bc there’s a decent sized cam in the engine that I don’t know the specs of. I took the timing set off before to see if there were numbers stamped on the cam and there weren’t any. There’s also no numbers stamped on the lifters. Could I just get a set of comp cam lifters for olds small block or do they have to be matched to the cam? They are hydraulic lifters
I would have to say that there is no way that the cam is not damaged too. If you want to be convinced put a good lifter on it and compare the lift with a different lobe. If it is an intake lifter compare it to another intake. Etc.
I've replaced an individual lifter and pushrod before. It's probably not ideal, you should replace the lifters and pushrods as a set. MAW replace the cam too. It's definitely a slippery slope.
I've replaced an individual lifter and pushrod before. It's probably not ideal, you should replace the lifters and pushrods as a set. MAW replace the cam too. It's definitely a slippery slope.
i definitely would replace all the lifters if I did but based off this thread I’m probably doin a cam
That's a lot of damage to the lifter. It would be really unusual - but not impossible - for the cam to be perfectly OK.
Depending on the car, you can pull the cam with the engine still in the car by just removing the radiator and A/C condensor (if equipped). I did that in an apartment parking lot way back when. They didn't like me very much.
There isn't much variety in flat tappet lifters - hydraulic or solid, and for hydraulic, there are a few special low-bleed ones or the Rhoads lifters. You don't necessarily need a low bleed rate or Rhoads unless you just want them. Low bleed is useful if you have high spring pressures for a hydraulic flat tappet.
The main thing will be finding a set that's ground properly as that's gotten rare. Look around to see what brands have gotten good reviews recently (*recently* is the important word!!!) and closely inspect them when you get them. There's some folks on youtube that actually show lifter grinding so you have an idea of what it's supposed to look like.
That's a lot of damage to the lifter. It would be really unusual - but not impossible - for the cam to be perfectly OK.
Depending on the car, you can pull the cam with the engine still in the car by just removing the radiator and A/C condensor (if equipped). I did that in an apartment parking lot way back when. They didn't like me very much.
There isn't much variety in flat tappet lifters - hydraulic or solid, and for hydraulic, there are a few special low-bleed ones or the Rhoads lifters. You don't necessarily need a low bleed rate or Rhoads unless you just want them. Low bleed is useful if you have high spring pressures for a hydraulic flat tappet.
The main thing will be finding a set that's ground properly as that's gotten rare. Look around to see what brands have gotten good reviews recently (*recently* is the important word!!!) and closely inspect them when you get them. There's some folks on youtube that actually show lifter grinding so you have an idea of what it's supposed to look like.
Sorry.
Do some oil flushes and filter changes to get all the crap out of the pan.
motors comin out and pans comin off
I was thinkin about going with a smaller cam so I could run air condition again (it’s in an 84 olds 98) so it’s not a race car. But the pushrods are 8.5 which is obviously not stock and I don’t know if I wanna mess around and change the size so I might just order a new set of 8.5” pushrods and find out what this cam is and get the same one I don’t know yet
Do you have stock rockers? It's a good idea, and pretty cheap, to get the Comp roller-tip set. The pinch nuts suck, and the pushrods are noodles, but the kit gets you started. Cam base circle doesn't change THAT much, so once you have adjustable rockers you're most of the way there.
Do you have stock rockers? It's a good idea, and pretty cheap, to get the Comp roller-tip set. The pinch nuts suck, and the pushrods are noodles, but the kit gets you started. Cam base circle doesn't change THAT much, so once you have adjustable rockers you're most of the way there.
Then a cam swap is no big deal. The tip sweep might move a little bit, so slightly longer or shorter pushrods might be needed to get it right on center. That's not really necessary unless it's totally out of whack.
Then a cam swap is no big deal. The tip sweep might move a little bit, so slightly longer or shorter pushrods might be needed to get it right on center. That's not really necessary unless it's totally out of whack.
how does one figure that out? It’s got a pretty big cam in rn and I’d like to go tamer
the pushrods that are in it rn are 8.5” .080
Check youtube for videos on rocker geometry and pushrod length. Generally you mark the top of a valve with a sharpie, adjust the rocker, roll the engine through two turns, see where it left the mark. Want it as close to the middle of the valve as possible. IIRC, longer pushrods move the contact point closer to the rocker stud, shorter pushrods move it away from the rocker stud.
You can get adjustable checker pushrods and checker springs. Checker pushrods have no strength and will buckle with regular valve springs. They also typically (in my experience with small blocks and edelbrock heads) have to be assembled in the engine because the adjuster nuts won't pass through the guide plate but they're too low on the push rod to just hang out above the guide plate.
Big cam to tame cam is actually a very small change when just looking at the cam. It's pretty amazing how subtle of a change on the cam can make such a big change in the engine. Especially the base circle - most cams are ground from the same blank and base circles usually don't move a bunch. e.g. changing max lift from 0.550 to 0.480 doesn't mean the base circle changes by 0.070. You take out the rocker ratio and you're down to 0.041, and the vast majority of that comes off the nose of the lobe. Going the other direction is a challenge (regrinding a small cam into a big cam) but that's hardly done because it's nuts. The standard cores have plenty of lift on the rough lobes to make most grinds.
Yup. Geometry doesn't have to be *perfect*, especially depending on use. Just check and make sure the roller tip stays on the valve and stays near the middle.
Yup. Geometry doesn't have to be *perfect*, especially depending on use. Just check and make sure the roller tip stays on the valve and stays near the middle.
thanks for all the replies you’ve been a really big help
do u have any suggestions of cam choice?. I don’t know what cam is in there rn but I guess I will find out when I actually pull it out. The engine has flat top pistons and makes a lot of compression. Basically I’m lookin for a tamer cam that I can run the air condition with. I make enough vacuum now to run power brakes but if I turn the ac on I lose power brakes
Guys like Mark Remmel (cutlassefi) can get a custom grind for you. If you want something off the shelf, then something in the 220-ish duration at 0.050", exhaust a few degrees longer than intake and 110 or 112 LSA should be close to what you want. A 214 cam is still quite mild, the 224 area starts to be fun and the 234 area is where things get spicy for a street driver small block. The 204 range cams were called "RV" cams.
Guys like Mark Remmel (cutlassefi) can get a custom grind for you. If you want something off the shelf, then something in the 220-ish duration at 0.050", exhaust a few degrees longer than intake and 110 or 112 LSA should be close to what you want. A 214 cam is still quite mild, the 224 area starts to be fun and the 234 area is where things get spicy for a street driver small block. The 204 range cams were called "RV" cams.
At what point do you start to lose vacuum? I only make like 11 inches with the cam I had
Duration and overlap both affect vaccum. Cams like the "thumper" cams have a real narrow separation angle, which means more overlap, which means less vaccum. But it has the idle lope that folks like. The tune is also important - I usually ran quite a lot more idle ignition advance than book spec and made several changes to the qjet.
I ran power brakes with a 224/230(ish), 110 LSA cam in a 350 with no problem.
Duration and overlap both affect vaccum. Cams like the "thumper" cams have a real narrow separation angle, which means more overlap, which means less vaccum. But it has the idle lope that folks like. The tune is also important - I usually ran quite a lot more idle ignition advance than book spec and made several changes to the qjet.
I ran power brakes with a 224/230(ish), 110 LSA cam in a 350 with no problem.
the cam that I was running had a pretty gnarly lope but I’d rather have ac and power brakes than a nasty sounding idle cause it’s in a 84’ 98 2 door which is a pretty heavy car and I’m runnin a 400 trans w a stock converter
now that I have the engine out again I could put a different stall converter in there but I don’t really understand the relationship between the converter and can choice. The car cruised good the way it was tho
High duration/high overlap cams have a very lopey idle because the idle air pulses are weak. Air is being pushed back into the intake a low RPMs and causing the air/fuel mix to just swirl around which also causes air flow through the carb to be turbulent which makes it difficult for the carb to correctly meter fuel. Lower duration/low overlap caps give a stronger idle signal - the intake valve is open during a narrower window and the exhaust valve isn't open as much at the same time, so air is flowing more consistently just into the cylinder. But at high RPMs this becomes a bottleneck.
At idle, a weak/lopey idle doesn't make much power. It's struggling to run. Hilariously we think that sounds good. When stopped with the engine in gear, the power the engine is making is getting absorbed by the fluid in the torque converter. A "tight" torque converter with a low stall has more aggressive vanes which makes the input and output lock in with each other more easily which is better at transferring the power from the pump (input) to the impeller (output) of the torque converter. There are some good videos on torque converters on youtube these days. The power from the engine is either being used to turn the wheels or it's being turned into heat or fluid movement inside the torque converter. A "loose" torque converter with a higher stall has less aggressive vanes which allows the input and output to slip more. So at idle, a "tight" torque converter takes all the power and turns it into heat because the fluid can't move as easily. Inside a "loose" torque converter there's more "room" (not literally space, but the ability for the input and output to spin separately) for the fluid, so the input can keep spinning while the output isn't. With a big cam, the engine isn't making much power, so turning the tight torque converter is too much of a load and causes the engine to die. A loose torque converter lets the engine spin more easily at low RPM. At high RPM, the fluid movement catches up and gets the input and output synced with each other, although the higher the stall the more slip that will occur.
"Stall speed" isn't anything magic, either. It's just a relative gauge of how tight or loose the converter is. In theory, if you keep your foot on the brake and stomp the gas then the engine will be able to rev up to the "stall speed" and then.... stall. It's not precise and there are a lot of "it depends", but it's useful for comparing converters and giving a converter builder an idea of how you want the converter to behave.
A big cam makes power higher in the RPM range, so you want to run the engine up there. A loose torque converter lets the engine rev up into the power band before the fluid coupling really starts to work, so you're in the power band all the time. Awesome for the drag strip, sucks for the street. But if you have a big cam, you have to have a loose converter or else the car won't be drivable at all. A torque converter that's too loose for your application will feel like you're driving a sponge - you have to almost floor it to get the car moving and the car reacts very slowly to mild throttle inputs.
"big", "small", "loose", "tight" are all relative. A stock cam usually has duration below 200 degrees at 0.050" and a stock converter usually has a stall speed below 1500. A "big" cam could have duration over 280 degrees at 0.050" and would need a converter with a stall of 4000 or higher.
A slightly looser converter really wakes up the car because it gives the engine a chance to build some power before really transferring it to the wheels.
I've run a bunch of different combinations. IMO, the 224-ish duration cams are the upper limit for a street driven small block, need a 2000-ish stall converter, and require quite a bit of tuning of the ignition timing and carb to get it to behave well in traffic.
For your application I'd aim for something lower, either a 204-ish or 214-ish duration at 0.050", and a slightly higher than stock stall converter. I have a soft spot in my heart for the TCI Saturday Night Special converters. Cheap, easy to get, and, at least for me, worked really well. You won't set any records, but for a full size car with a 350, well, it takes a lot of determination to get real power and good manners.
I usually just talk about intake duration. Exhaust duration, for a typical Olds, you'll want to be 5 to 10 degrees more duration than the intake. The Olds exhaust port is particularly bad, and the rest of the system usually isn't great, so extra exhaust duration really helps. A lobe separation angle of 112 is very mild and gives a good idle, but 110 is pretty common as a trade-off between power and manners. 108 or 107 start getting int the "lopey" range - great for high end power, sucks for idle.
One thing that sucks is catalog availability for Olds cams is dying off rapidly. All the manufacturers can still grind them, but you're more likely looking at a custom grind which means someone that understand their lobe catalog needs to spec out the cam and order it from them. A flat tappet lifters are a real #$%^&#$%^ now.
High duration/high overlap cams have a very lopey idle because the idle air pulses are weak. Air is being pushed back into the intake a low RPMs and causing the air/fuel mix to just swirl around which also causes air flow through the carb to be turbulent which makes it difficult for the carb to correctly meter fuel. Lower duration/low overlap caps give a stronger idle signal - the intake valve is open during a narrower window and the exhaust valve isn't open as much at the same time, so air is flowing more consistently just into the cylinder. But at high RPMs this becomes a bottleneck.
At idle, a weak/lopey idle doesn't make much power. It's struggling to run. Hilariously we think that sounds good. When stopped with the engine in gear, the power the engine is making is getting absorbed by the fluid in the torque converter. A "tight" torque converter with a low stall has more aggressive vanes which makes the input and output lock in with each other more easily which is better at transferring the power from the pump (input) to the impeller (output) of the torque converter. There are some good videos on torque converters on youtube these days. The power from the engine is either being used to turn the wheels or it's being turned into heat or fluid movement inside the torque converter. A "loose" torque converter with a higher stall has less aggressive vanes which allows the input and output to slip more. So at idle, a "tight" torque converter takes all the power and turns it into heat because the fluid can't move as easily. Inside a "loose" torque converter there's more "room" (not literally space, but the ability for the input and output to spin separately) for the fluid, so the input can keep spinning while the output isn't. With a big cam, the engine isn't making much power, so turning the tight torque converter is too much of a load and causes the engine to die. A loose torque converter lets the engine spin more easily at low RPM. At high RPM, the fluid movement catches up and gets the input and output synced with each other, although the higher the stall the more slip that will occur.
"Stall speed" isn't anything magic, either. It's just a relative gauge of how tight or loose the converter is. In theory, if you keep your foot on the brake and stomp the gas then the engine will be able to rev up to the "stall speed" and then.... stall. It's not precise and there are a lot of "it depends", but it's useful for comparing converters and giving a converter builder an idea of how you want the converter to behave.
A big cam makes power higher in the RPM range, so you want to run the engine up there. A loose torque converter lets the engine rev up into the power band before the fluid coupling really starts to work, so you're in the power band all the time. Awesome for the drag strip, sucks for the street. But if you have a big cam, you have to have a loose converter or else the car won't be drivable at all. A torque converter that's too loose for your application will feel like you're driving a sponge - you have to almost floor it to get the car moving and the car reacts very slowly to mild throttle inputs.
"big", "small", "loose", "tight" are all relative. A stock cam usually has duration below 200 degrees at 0.050" and a stock converter usually has a stall speed below 1500. A "big" cam could have duration over 280 degrees at 0.050" and would need a converter with a stall of 4000 or higher.
A slightly looser converter really wakes up the car because it gives the engine a chance to build some power before really transferring it to the wheels.
I've run a bunch of different combinations. IMO, the 224-ish duration cams are the upper limit for a street driven small block, need a 2000-ish stall converter, and require quite a bit of tuning of the ignition timing and carb to get it to behave well in traffic.
For your application I'd aim for something lower, either a 204-ish or 214-ish duration at 0.050", and a slightly higher than stock stall converter. I have a soft spot in my heart for the TCI Saturday Night Special converters. Cheap, easy to get, and, at least for me, worked really well. You won't set any records, but for a full size car with a 350, well, it takes a lot of determination to get real power and good manners.
I usually just talk about intake duration. Exhaust duration, for a typical Olds, you'll want to be 5 to 10 degrees more duration than the intake. The Olds exhaust port is particularly bad, and the rest of the system usually isn't great, so extra exhaust duration really helps. A lobe separation angle of 112 is very mild and gives a good idle, but 110 is pretty common as a trade-off between power and manners. 108 or 107 start getting int the "lopey" range - great for high end power, sucks for idle.
One thing that sucks is catalog availability for Olds cams is dying off rapidly. All the manufacturers can still grind them, but you're more likely looking at a custom grind which means someone that understand their lobe catalog needs to spec out the cam and order it from them. A flat tappet lifters are a real #$%^&#$%^ now.
you’ve been a really big help and filled in some gaps in my knowledge. Thank you
do u know if any one having any luck with any of the off the shelf cams available like the edelbrock performer plus for olds small block?
I haven't paid attention to flat tappet cams in quite a while and things have changed a lot in the past 10 years with roller conversions becoming more common. I have a personal hatred for Comp's grinds (disappointing performance back in ~2000 with the Extreme Energy stuff). The only flat tappet stuff that seems to have been designed since the 80's was the Lunati Voodoo and Harrold's (I keep forgetting his last name) newer lobes. I had one of Harrold's later grinds that was an absolute dream for my combination. Lunati stuff got slaughtered in the corporate takeover, Harrold's company folded...... His lobes were bought by Bullet Cams so they can still be ordered. It's best to find someone to order a custom grind for you. Mark (cutlassefi) on here is a good option, as well as Bernard Mondello (Bernard, although I think the old Mondello shop finally closed). There are plenty of other folks like Bill Trovato, Rocket Racing, maybe even Peyton Hunt, but they focus on racier stuff.
Lobe catalogs are fun to look at, but the differences can be very subtle. I'd recommend reading one for fun - I think Bullet used to publicly post theirs - but it's tough as a novice to make decisions off of those. I've been mucking with this for a while and I still wouldn't want to make those decisions myself.
