[1badbigblock]

I'm looking at buying a used GM Crate engine 350 290 HP, does anyone know if GM breaks in the flat tappet cams at the factory in Mexico?

I'm looking at buying this 290HP 350 apparently has 3500 miles on the engine, I asked the owner if he broke in the cam and he said he bought the truck with the engine already in it. I asked him what oil he used and he said he did not change the oil since he's owned it, he said he had to adjust the valves (which worries me).

The engine is no longer in the truck as the owner has gone LS engine. The engine is on stand.

How could I verify if none of the camshaft / lifters are worn or going?

Could I hook up the starter and turn the engine over while I mark each push rod to verify each push rod is spinning?

I was going to cut open the GM oil filter to see if there is any metal?

What are your thoughts?

Thanks

 

[69_CHEV_ELLE]

click for GMPP's instructions.

Pull the valve covers and the cam. But since you had to ask, my guess is you won't know what you are looking at. Maybe you've got a buddy that would know and go with you for a couple beers?

 

[chaze]

click for GMPP's instructions.

Good point. GM instructions call for generally a gentle break in during first 500 miles - no static break-in like recommended by most aftermarket cam manufacturers.

But I performed the static break in on mine anyway.

 

[Chevelle 1969]

click for GMPP's instructions.

Pull the valve covers and the cam. But since you had to ask, my guess is you won't know what you are looking at. Maybe you've got a buddy that would know and go with you for a couple beers?

How Do you pull the cam with just removing the Valve covers?
Its more involved removing the cam than just pull the Valve covers.

 

[shovelrick]

Can you just pull the intake to look at the cam? While it's off use a dial indicator with a mag base to check lift at valve tip or rocker arm

 

[Kirk's67SS]

I'm looking at buying a used GM Crate engine 350 290 HP, does anyone know if GM breaks in the flat tappet cams at the factory in Mexico?
I'm looking at buying this 290HP 350 apparently has 3500 miles on the engine, I asked the owner if he broke in the cam and he said he bought the truck with the engine already in it. I asked him what oil he used and he said he did not change the oil since he's owned it, he said he had to adjust the valves (which worries me).
The engine is no longer in the truck as the owner has gone LS engine. The engine is on stand.
How could I verify if none of the camshaft / lifters are worn or going?
Could I hook up the starter and turn the engine over while I mark each push rod to verify each push rod is spinning?
I was going to cut open the GM oil filter to see if there is any metal?
What are your thoughts?Thanks

Run Forest Run
I would not even look at it

I bought my current BBC when it was in a Camaro as the guy was going to a 540 ci one
from the shop I had known for 30 years

 

[Matt 69]

If the engine has 3500 miles on it, the cam is already broken in, or wiped out.

 

[69_CHEV_ELLE]

How Do you pull the cam with just removing the Valve covers?
Its more involved removing the cam than just pull the Valve covers.

No kidding?

Reread what I posted one more time. The "and" is there for a reason. Hint, pulling both does not mean pull one to get to the other.

He's concerned about the cam, lifters, AND valves that have already been adjusted. Owner also said he hasn't changed the oil. Why would you not pull the valve covers?

 

[mrpaticular]

There are several bad reasons for hydraulic valves out of adjustment. Cam makers have always had a break in process. Factories never did. No assembly lube. Put it together, drive it off the assembly line to transporter, to dealer, to someone test driving it.

 

[71malibuu]

Pull the plugs. Then you’ll know if all the cylinders are firing. If one is not find out why. I would not be worried about the cam being wiped. I’d it is you can choose a cam and lifter flavor that you like. If it’s not it’s already broken in and should be out of the danger zone. Me personally, I would pull the plugs, pull the valve covers, and have the guy selling you the engine show you exactly how he adjusted the valves. That should tell you everything you need to know.

 

[oldcutlass]

Whats the price? These are inexpensive to purchase new.

 

[MikeN]

Don't think I would pay more than $300-$500 for that. And that assumes I plug it into my car and start driving. If I have to pull it apart and inspect the cam, I'm not interested at any price.

 

[1badbigblock]

I went and looked at the engine, All the plugs looked the same, to me they looked a little lean.

I used a dial indicator and measure each lobe at the spring retainer, here are the specs, would these low measurements caused by improper lifter preload or lifter bleed off? the engine has not ran for 2 weeks now.

#1 Exhaust - .277"
Intake - 295"
#3 E-. 309"
I - .288"
#5 E- .304"
I - .303"
#7 E - .255"
I - .253"
#2 E -.230"
I- .230"
#4 E- .252"
I - .270"
#6 E- .340"
I- .322"
#8 E- .460"
I - .425"

the 290HP cam spec is .450" lift / .460' Exhaust

 

[69_CHEV_ELLE]

She's running lean for sure.

 

[BillK]

The plug looks fine to me. Most modern engines are bone white. That has a little color . I would leave it alone and drive it.

 

[1badbigblock]

The plug looks fine to me. Most modern engines are bone white. That has a little color . I would leave it alone and drive it.

okay thank you, how about the camshaft readings? are the low numbers caused by lifter bleed off or misadjusted preload?

 

[MikeN]

Plugs look great, it appears to have had regular oil changes and/or not driven much. If you can get it cheap, it is likely a good engine. I'm still thinking a used, nothing-special 350 is in the $300-$500 range.

 

[BillK]

I dont think you can accurately measure the cam like that. If the engine ran more than 500 miles the cam is long since broken in and should be fine. Stop overthinking it

 

[RAMBO]

I wouldn't pay much for one of those engines unless you can hear/see it running. $500 or less.
I'd much rather have an older (pre-83 ?) block and heads that would be worth rebuilding if it turns out to need it.

 

[cv67]

Agre...its fine or wiped. Would the guy perhaps let you pull the intake and inspect the lfiters?
I would never buy a used engine unless I knew the person. Engine may have 3500 miles on it but most times guys are full of it..
If it only had 3500 mi and needed valves adjusted I doubt it would be from the crimped part of the nut being worn. It should never have needed it but who iknows?

Keep us posted.
Im guessing the minimal spring pressure and gentle ramps of GM cams "dont need the usual break in" or they may have a good lifter? maybe some builders or machininst can pipe in.