Increase in oil pressure with new cam? 383

[StockMan]

I installed a new cam in my 383.  Prior to this the motor had around 65lbs cold and 55lbs warm.  This is with a high volume pump.  I installed a new cam (on the old bearings) and the pressure is now consistent at 70lbs?  I can't imagine that the journals on the old cam were worn that much??  I didn't actually measure them.  The new cam slid in and is working fine.  Although, I've been told that it is not a good cam for the stock 383 (an old crane fireball).  And, is it safe to install a new cam on old bearings?

Thanks.

[firefighter3931]

The cam journals on the new camshaft are larger than the worn journal on the original. No problem running a new cam with old cam bearings as long as those bearings are in good shape. 


Ron

[StockMan]

Thanks again...  I installed a new roller timing chain and sprockets.  I've never tried to dial in cam, I could never understand how one would move the sprocket on the cam, on my sprocket there is only one bolt hole...

[dukeboy_318]

hats the specs on your cam??? if you over camed it, you'll lose power instead of gain, listen to firefighter, he knows his stuff

[StockMan]

Thanks for all your help!?  Maybe you can assist me with a question that I always wondered about.  I've got 250 casting heads on my 383 and am curious when Chrysler stopped making them and started with the 906s, and why??  Was the 250 casting the same as the 906, and, was the 250 used on any 440s?

Thanks

Oh, and thanks for all your help FireFighter. (Fellow Canadian!!)

[Challenger340]

This is from "memory only", so take it at that.

The "250" castings were not the same as the 906 heads, and never offered on 440's to my knowledge, as too early ?
Different and flatter Intake port, similar to the older 516 closed chamber casting, but a better,starighter exhaust port, or so we thought at the time, although we never flowed them.

The 915 & 906 heads, were the only pure "huber hump" Intake ports, meaning highest short turn in front of the Valve, and highest bowl potential above the Valve.
But, without major modification to that short, and .600" lift Cams, they just aren't many benfits to the higher "huber hump" over the later & shorter, "siamesed hump" short turn as incorporated in 346,453, etc., heads.
Actually the 452 type perform better for most applications.

Flow is flow performance-wise, whether it comes crashing out the backside or not(452).

Dunno 'bout the 250 flow-wise, but from memory I thought they'd probably work just fine.

Bob out.

[Challenger340]

Did you notice if the Oil feed hole on #4 journal on the new/old Crane Cam was smaller than the stocker ?

[StockMan]

Thanks the education on the heads.  Nobody has been able to answer this question until now.  I didn't actually notice if the oil feed hole was smaller on the crane as compared to the factory cam...  This is something I didn't think of checking.  In your experience would this have been something the manufacturer would have done?  If so, I would be curious why?  And, I'll ask you this, am I in for a powerless 383 'Slug' with the crane fireball installed?  The config is

Orig 383 9.2:1 60K on it
140 lbs all the way through
4bbl 4401 carter AVS stock intake
HP Exhaust
2 1/4 dual exh
open 3.23s

[firefighter3931]

Bob is correct on the 250 casting info.....it's basicly a 906 head which used a different casting number. The first open chambered BB cylinder head was in fact the 250 casting which was introduced for the 68 model year. Early production cars used this casting then sometime later in the year the 906 casting number showed up....but fot all intents they are identical.

These are descent heads and will work fine for your applicaton. With some tuning and tweaking the engine will make descent power allthough the cam profile is essentially wrong for the rest of the combination.



Ron

[StockMan]

Thanks everyone, I think I'll stop now...