What oil weight should I be using and why?

[jcode68]

I have a 347 from CHP with hydraulic roller cam & valvetrain, 8 qt oil pan, high volume oil pump. CHP suggested I run 20w50, which I did for a while, but when I changed my oil I decided to go with Mobil 1 10w30 synthetic based on input from knowledgable people etc. Using the 10w30, I have very noisy rocker arms and it's driving me nuts (sounds like a handful of marbles rolling around under the valve covers at idle). I'm not sure if they were as noisy using the 20w50 or not, but am probably going to go back to the using 20w50 to find out. I have adjusted the rockers and am starting to wonder if I have lifter problems. So my specific questions are:

1. Why would CHP suggest 20w50 oil? Most I talk to about it think it's too heavy/thick, but I'm sure CHP has a reason.
2. What are others with a similar build running? Do you have loud rockers?
3. Would 20w50 be better for pumping up the lifters and decreasing the amount of bleed down and thus lowering/minimizing the amount of chatter in my rockers?

I have read roller valve trains are noisy by nature, but I really don't think what I have is right or acceptable. Thanks in advance.

 

[blown65]

Why don't you ask chp why and if they are ok with 10-30 instead? I'm sure either one is fine though.

 

[zookeeper]

I use Valvoline 20W-50 VR-1 in my car, but I think the next oil change is gonna see something a bit more like 10W-40. I haven't had any problems or anything, but I live in a cooler climate and don't rev the snot out of my car, so I suspect the thinner stuff will be more like what I need.

 

[jcode68]

Why don't you ask chp why and if they are ok with 10-30 instead? I'm sure either one is fine though.

I plan to call CHP again next week to talk with them about it, but wanted to get a little more educated first.

Zookeeper - why did you select the 20w50 in the first place? I live in MA, but I don't drive my car beyond October, so doesn't see any real cold weather.

 

[zookeeper]

LOL, don't laugh but it was the only VR-1 they had on the shelf and I wanted something with ZDDP in it.

 

[jcode68]

LOL, don't laugh but it was the only VR-1 they had on the shelf and I wanted something with ZDDP in it.

Real scientific decision making process, I love it!

 

[zookeeper]

eenie-meenie-miney-moe...

 

[D.Hearne]

I run 20-50 in mine in summer, 10-40 in winter. Both are a bit noisy with either as far as valvetrain noise goes. Both engines have been running for 4-5 years now and nothing bad has happened with regard to the noise. It's completely normal. Ford even went as far as designing a special set of stamped steel valve covers for the 93 Cobra 5.0 to help mask the noise. These were doubled walled stamped steel covers.

 

[Cobra ssc]

I run 20-50 in mine in summer, 10-40 in winter. Both are a bit noisy with either as far as valvetrain noise goes. Both engines have been running for 4-5 years now and nothing bad has happened with regard to the noise. It's completely normal. Ford even went as far as designing a special set of stamped steel valve covers for the 93 Cobra 5.0 to help mask the noise. These were doubled walled stamped steel covers.

Did Ford use the same valve covers on the 94-95 Cobras as well?

 

[JonK]

I'll be following to see what the reply is from CHP, I had a 333 built from my 289 locally with roller rockers/hyd. cam that hasn't been started or installed. I plan to use Mobil 1 10W30 w/compcams additive for ZDDP after 3K break in.

My builder advised that thicker oil would cost a little HP (probably not significant unless you're doing 1/4mi. I suppose). If I have too much clatter I'll switch to 20W50 as 20* is the lowest it gets in TN. I ran 20W50 for years in a 351W in a '70 with no issues but guess i could have lowered my ET a little with lighter oil.
Jon

 

[D.Hearne]

Did Ford use the same valve covers on the 94-95 Cobras as well?

Wait, I was wrong there. The double walled covers were used on the 94-95 Cobras and the 96-up Explorer/Mountaineer 5.0's. I went back and looked, they're actually three layered, having a mastic layer sandwiched between the steel layers.

 

[jcode68]

Thanks for the resonses guys.

Dhearne - I have read posts where you suggest this is normal, but I'm not sure the racket mine are making is considered normal. I will have to see if I can get a short video of it posted for you guys to listen to. Hope it translates well.

JonK - I will post back after speaking with CHP. I don't have a problem with using 20w50, just want to understand what the reasoning is as others I talk to seem to think it's very heavy and would be prone to causing starvation up top until warmed up to temp. I dunno

 

[squidz]

i have a 347 as well and i run 20w50. This was recommended to me by my builder because strokers run quite a bit hotter than stock 302's. I had chatter as well froms rockers and a valve/rocker adjustment cleared up the noise.

 

[D.Hearne]

Thanks for the resonses guys.

Dhearne - I have read posts where you suggest this is normal, but I'm not sure the racket mine are making is considered normal. I will have to see if I can get a short video of it posted for you guys to listen to. Hope it translates well.

JonK - I will post back after speaking with CHP. I don't have a problem with using 20w50, just want to understand what the reasoning is as others I talk to seem to think it's very heavy and would be prone to causing starvation up top until warmed up to temp. I dunno

Nothing to worry about as to starvation up top, 20W-50 isn't THAT thick. The noise I get is often compared what's to a sewing machine.

 

[jspagna1]

You can see from my signiture below the motor I put in my car 11 years ago now. I have always run 20W-50 in my motor from day one and have never deviated. I'm in CT and we get the same cold you do. I also only drive my car from April 1 - Oct.31. I put anywhere from 1,000-1,500 miles per year and my motor runs as strong today as it did when I put it in.
Stick with it, you won't be sorry.