Which camshaft with my setup? (SBC 350)
11-05-2025 | 02:17 AM
#11
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From: BC
I think I purchased a bottle of zinc additive from a GM dealer, and added it to the oil. Fired it up quickly, and let it run around 2500 - 3000 rpm for 15 minutes. Then I changed the oil and filter and ran it. However, with today's oils and cam and lifter quality, there is always some risk, which is one reason OEM's have switched to hydraulic roller cams. I don't remember for sure, but I think I used 20W-50 VR1 Valvoline Racing oil because it has a high zinc content for the camshaft break-in. I didn't change the bearings, rings or pistons, so I did not have to break the engine in. I also had flat top OEM pistons with 4 valve reliefs and the 64cc Vortec heads worked fine.
1200-1600ppm zinc.
Too much zinc creates a film too thick...that it fractures off.
DP rates oils have reduced the Calcium from as high as 3500ppm to 1000ppm. Calcium is a detergent, but would clean off the zinc trying to do its job.
SP VR-1 oil is low calcium, and high zinc around 1300ppm zinc ish.
11-05-2025 | 03:45 AM
#12
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From: Germany - Stuttgart
Just make sure to use proper flat tappet breakin oil, fill fuel bowls and try and set timing so she fires off right away, don’t crank engine too long, also I am super finicky and change oil right after 30 minute cam breakin, there’s tons of stuff in a fresh rebuild no matter how well you clean it first. You can’t change oil too often on fresh motor, get it to fire right away and get to 2500rpm for 20 to 30 minutes and check for leaks, good luck
yes I will use a base oil which will have a high zinc portion and will additionaly add a break in additive with more ZZDP. Like the LucasOil Extreme Duty Marine Engine Oil SAE 20W-50 and and the TB zinc-plus additive.
But I will also ask my engine builder what he recommends. He installs those Elgin camshafts quite often.
The carb and the fact that the old engine is removed from the boat and the new one goes in will lead me to fuel starvation on first start. Good idea with priming the carb, I will do that.
I also bought a priming tool to get the oil to all the bearings and the cam before I fire it up.
What I don't know is if the cam is pre-lubed with assembly lube. But when I change the heads I will take out the lifters and brush the cam again with some moly assembly lube.
I hope it works out like that.
Greetings Ben
11-05-2025 | 07:31 AM
#13
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From: bellingham wa.
As tartilla mentioned too much zddp is bad if you use a proper flat tappet breakin oil it will be fine, engine builder should have put a good dose of assembly lube on camshaft during install, of course couldn’t hurt to pull lifter and put some on base of lifter, also check to see if lifter rotate easily in lifter bore, if they don’t rotate easily that could speed bad news during breakin. My guy would assemble engine leave intake manifold off have all rocker arms set and put a small white paint dot at edge of each lifter and rotate crank with ratchet and see if lifter rotate. There are lots of good aftermarket oils out there for flat tappet lifter after breakin that don’t need additional zddp, after 30minute breakin, change oil(it’s cheap) and filter put fresh oil and filter, hopefully all goes well, I always find it very stressful breaking in new engines. Good luck
11-05-2025 | 11:23 AM
#14
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From: BC
I wouldn't run a Lucas product in anything.
https://pqia.org/lucas-hot-rod-class...-40-motor-oil/
2700+ ppm zinc. Tried to find analysis for 20w50 and marine. I suspect it's all destruction level high zinc.
+ you want to add more zinc...not a plan for success. But we've all been inundated with the zinc scare.
It won't matter how good your breakin oil is if the lifters are not concave from center with 0.0015" to the edge.
FT lifters need to have a smooth surface but rough enough have some friction IOT turn them.
https://pqia.org/lucas-hot-rod-class...-40-motor-oil/
2700+ ppm zinc. Tried to find analysis for 20w50 and marine. I suspect it's all destruction level high zinc.
+ you want to add more zinc...not a plan for success. But we've all been inundated with the zinc scare.
It won't matter how good your breakin oil is if the lifters are not concave from center with 0.0015" to the edge.
FT lifters need to have a smooth surface but rough enough have some friction IOT turn them.
