Flat Tappet question
Flat Tappet question I have a new flat tappet cam and I have a set of used lifters with 100 miles on them sitting on the shelf. Can I get away with using the old lifters?
I obviously am not going to use the lifters that are in the motor now b/c they are going straight to the trash can (along with the stock cam from 76). I have this set of Hydraulic flat tappet lifters from an engine that spun bearings after 100 miles and they shouldn't be too broken in i don't think.
This is not a high performance application it will prolly never see over 5500 ever.
I obviously am not going to use the lifters that are in the motor now b/c they are going straight to the trash can (along with the stock cam from 76). I have this set of Hydraulic flat tappet lifters from an engine that spun bearings after 100 miles and they shouldn't be too broken in i don't think.
This is not a high performance application it will prolly never see over 5500 ever.
well, crap. that's a resounding no then. 
What's the break-in procedure again?
i always hear 20 min 1500 rpm change filter then 500 miles change oil and have at it.
BTW this is NOT a new motor that it's going in so i don't have to seat any rings
What's the break-in procedure again?
i always hear 20 min 1500 rpm change filter then 500 miles change oil and have at it.
BTW this is NOT a new motor that it's going in so i don't have to seat any rings
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http://www.hotrod.com/techarticles/e...ech/index.html
http://www.aera.org/eptb/TB2333R.pdf
the break in procedure is a fast rpm so
1) the lifters spin in their bores and establishes a correct wear pattern for lack of better explanation to the cam lobe. When they don't spin, the cam lobe and lifter wear in the same spot on each other and that's what causes the lifters to eat the cam. I thought the lifter surface was hardened, or is much harder than the cam lobe, i do know they have a convex shape which is why they spin.
2) the higher rpm ensures adequate oil flow to the cam, lubrication is essential when initially running in a new cam and/or lifters where a new wear pattern is going to be established. also a good idea to coat the new lifter bottoms with a break-in lube or grease to prevent scuffing on initial startup when they're is no oil flow.
you also want to either prime the oil pump or spin the engine over prior to dropping the lifters in so you will get oil flow as quickly as possible once the engine starts spinning.
http://www.aera.org/eptb/TB2333R.pdf
the break in procedure is a fast rpm so
1) the lifters spin in their bores and establishes a correct wear pattern for lack of better explanation to the cam lobe. When they don't spin, the cam lobe and lifter wear in the same spot on each other and that's what causes the lifters to eat the cam. I thought the lifter surface was hardened, or is much harder than the cam lobe, i do know they have a convex shape which is why they spin.
2) the higher rpm ensures adequate oil flow to the cam, lubrication is essential when initially running in a new cam and/or lifters where a new wear pattern is going to be established. also a good idea to coat the new lifter bottoms with a break-in lube or grease to prevent scuffing on initial startup when they're is no oil flow.
you also want to either prime the oil pump or spin the engine over prior to dropping the lifters in so you will get oil flow as quickly as possible once the engine starts spinning.
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Verdad Gallardo I showed my mechanic my lifters and he said he wouldn't recommend it but he told me that he had re-used some when he built engines for himself. he told me to take the lifters and use a piece of sandpaper on perfectly flat glass (table top or such) and gently polish the bottom of the lifter till they were perfectly flat.
Yeah, I know i'm gonna get flamed for this but I can't justify buying $60 lifters to use with a $35 camshaft it totally kills my budget. If i didn't have a budget i'd go roller.
Also, what oils still have the right amount of additives in them for a flat tappet??
I like using 15w-40 Rotella in my 4x4 but recently used the 2-gallon walmart supertech b/c it leaked a lot of oil. this stuff any good (as far as additives are concerned)?
Yeah, I know i'm gonna get flamed for this but I can't justify buying $60 lifters to use with a $35 camshaft it totally kills my budget. If i didn't have a budget i'd go roller.
Also, what oils still have the right amount of additives in them for a flat tappet??
I like using 15w-40 Rotella in my 4x4 but recently used the 2-gallon walmart supertech b/c it leaked a lot of oil. this stuff any good (as far as additives are concerned)?
As far as sanding the bottom of the lifters till they are flat thats just flat out wrong, the bottom of the lifters are concaved (I think that's the word) meaning they curve up in middle. This is what makes them spin in their bores. If you sand them down so they're flat they wont spin and you'll be fucked.
As for Rotella I do agree with you there, IMO its the best oil you can buy, I run it in all my cars and even use it in my lil sisters Audi. Before I found out about it though I ran castrol 20W-50 oil designed specifically for older engines with flat tappet cams, even with these oils though you still MUST use a break in additive.
Last edited by Drumer919; Dec 10, 2008 at 08:00 PM.
Staging Lane
Joined: Nov 2006
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From: Modesto, CA
Use new lifters man, then your $35 camshaft will be a round metal stick worth nothing.
Bite the bullet, buy the lifters.
Maybe your "Mechanic" got away with this 25 years ago when oil had higher zinc levels and what not, but now adays, it's not even worth the risk on a JY motor.
Bite the bullet, buy the lifters.
Maybe your "Mechanic" got away with this 25 years ago when oil had higher zinc levels and what not, but now adays, it's not even worth the risk on a JY motor.
http://www.compcams.com/Technical/FAQ/FAQLifters.asp
Hydraulic Flat Tappet lifters feature a “flat” lifter face (actually, it’s slightly convex to promote rotation)
i also thought it's a hardened material and if you start sanding them you may be taking away that hard surface and exposing a softer underlying surface which will really wear and cause problems, i would not sand them, or at least call comp or crane tech and see what their opinion is before you do.
read this: http://www.compcams.com/Base/pdf/Fla...chBulletin.pdf
you're standing firm on not going over budget by $60, damn you should be the car czar overseeing this bailout bullshit.
if you know the previous engine ran fine with them, for only 100 miles which is what a few hours, and if the spun bearing damage wasn't massive affecting other parts in the engine, and the lifter surfaces look good and the cam lobes they were to also look good then I doubt you'll have any problems reusing them. just moly paste the cam and lifters well, use a zddp breakin additive with a 15w-40 oil and ensure the engine will fire right up and get it to 2000+ rpms for the first 15-20 min.
Last edited by 1 FMF; Dec 11, 2008 at 05:24 PM.
