Chevy 283 questions...compression check numbers OK?

Howdy, newbie here.
Sooooo.....I took a truck from my dad that has been sitting for about 10+ years, Got it running, so far so good. 37 Ford with a 283 SBC and powerglide. I changed plugs and did a compression check this weekend. Seems low, though it runs well and has no smoking issues, so maybe it's normal. The lowest 2 cylinders were 120psi, with the highest at 130....the rest in between. Pretty uniform, so that's good. Just wondering what's normal on these motors.
I did a search to check the block numbers (F0220WA), and it looks to be a '65 283, 175hp 2 brl motor. The intake looks to be a 327 4 brl manifold (3844457). Carb was junk so I put an Edelbrock 1405 (600cfm) carb on it.
I'de like to get a bit more ooomph out of the motor, but don't want to remove it. If the compression numbers seem reasonable, I may go to a larger cam...maybe a better intake as well.
Any input appreciated.

 

120 to 130 is just fine!

 

try headers, roller rockers, alum intake, rear end gears 373

 

Rule of thumb - atmospheric pressure is around 14.7 PSI - take an 8:1 engine and you should have a compression around 8x that number or 117 PSI. 9:1 - 9x or around 132 PSI.... Of course cams and such can vary that number but for a basic street engine it gets you real close to knowing if it's "good" or not...

The compression ratio is nothing more than the ratio of the volume of the cylinder while at the lowest point in the stroke (which at low speeds or rest should be 'filled' with around 14.7PSI or 1 atmosphere) vs the volume of the cylinder at top dead center. ***uming everything seals up well the theoretical max is around that number - there is a potential for higher "ram air" effects or relying on exhaust reversion or some other way to get more than 14.7PSI in the cylidner before compression but that happens at a higher engine speed vs. cranking

If anyone ever told you that their 9:1 engine cranked 170 PSI they're smoking something good or their gauge is all sorts of messed up.... Hence the reason that most say to look at the variation between cylinders vs the actual # - the cheap gauges are cheap for a reason...

 

Good info, thanks much. From those numbers, it looks like I'm good....especially for a 40+ year old motor. (it was put in the truck around 72-73 or so)

 

If I had that truck and that compression, I would be a happy camper.

 

that is a cool truck! there is nothing wrong with the motor at all as far as the compression. drive it and have fun!

 

Good looking truck! Eng. comps sound ok. I'd drive the wheels off of it!!!
A vintage Edelbrock C3BX or a new Performer RPM intake and a 350HP 327 cam should work well with your setup...
Fair idle, good power, & works ok with the stock converter

http://www.cranecams.com/?show=browseParts&action=partSpec&partNumber=WG996K&lvl=2&prt=5
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I had been thinking of the 300hp 327 cam. Which do you guys think?

 

Interesting. I checked a 100,000 mile Pontiac 389 that was a 10:1 motor and got readings in the 150-155 range on all but one (and that one was 125 or so). Sounds like it was about right except for whatever was wrong with the one cylinder. Was blowing a lot of smoke out the draft tube when last run, though.

 

Guess I'll ask about the oil pressure too. Cold, it's up there....40-50psi, but once warmed up, cruising at 60mph or so it's only about 20psi.....going down my dirt road home, just a tad above idle, it's around 10-12psi. Lower than I'm used to. Is this common with the older motors, or does this one need a new pump?
It's got fresh 10-30 right now.

 

that's kind of low! and it could be the bearings, not just the pump worn. We like to se at least 30 psi at cruising speed, 40 would be more re***uring.

 

Compression sounds good. If it is a 175hp 2bbl motor that cam may make it run worse. Those motors had small valve heads that didn't flow all that well. That was the base 283. check timing and check gearing in the rear of the truck first, before cam. Everything has to work together. Tall gears, big cam, might just get you less umph! Big cams sound cool but most only operate well at higher rpm. Been there!

Cool truck, by the way!

 

Ditto what everyone else said about compression ratio, and especially what squirrel said about bearings. Had the same issue with the 300 in my '64 Skylark. Thought it was the pump, rebuilt it, and it turned out that the bearings were bad. New crank and rod bearings = happy oil pressure numbers.

 

Oh yeah, way cool truck!!!

 

10psi fully warmed up is pretty low for a sbc. Sounds like things are getting slack in the lower end. As far as better acceleration goes, the Powerglide is probably the main suspect for lackluster 0-60 performance.

 

I just pulled a really, really tired 283 out of my '62 Suburban. As tired as it was, there was always 40psi of oil pressure while cruising. I'd put in 10/40 or even heavier oil. 10/30 seems a little thin to me, especially on a motor put together when they were running 50 weight!
And like everyone else has said, kick-*** truck. I have a friend who had an almost identical '38, right down to your engine combo, about the time yours was put together.
Finally, swapping the cam is going to be a h***le. You said you don't want to pull the engine, but you'll have to pull the radiator out, plus drop the oil pan to get the timing cover off. If the engine isn't leaking now, it will after you drop the oil pan with the engine still in the ch***is.
Get a set of COMP stamped steel 1.6 rockers (easy to swap, no guide plates needed), a Performer intake (or a C3B if you're stuck on the early details...that's what I put on the crate 350 in my Suburban), and an electronic ignition. If you've got ram's horn manifolds on it, get either a set of 2.5 Corvette Ram's horns (expensive, whether you find originals or get reproductions), a set of Speedway 2.5-inch iron ram's horns, or a set of shorty headers.
Mix thoroughly, drive and enjoy!

-Brad

 

The cam I got is pretty mild.... Duration at 050 inch Lift:204 int./214 exh., 0.420 int./0.442 exh. lift. Picked up an older 3 2-barrel setup that's fresh as well.
I'll try a 20-50 oil or so, and see how it goes. If it doesn't improve much, I'll just pull it out and go thru it. Thanks for the info guys.

Here's a more recent pic....

 

C'mon, man. With that second picture, you're just showing off.

Just kidding!! Really cool truck...

 

Wish my dad had a truck like that just sitting for 10 years, nice truck.

Try thicker oil, even 20W-50 would not hurt. I agree it sounds like your bottom end is a bit worn on the bearing clearances. If it runs fine, I wouold leave it and use the thicker oil. As many suggested here.

A 283 was never a low-end torque monster, it needs better gears. The PG trans also hurts your low end. Swap a turbo 350 trans and you will have much better performance. Same length as about a bolt-in as swaps get. What rearend gears do you have? A 283 is not going to be hurt by a bit more rpms when cruising, that short 3.00 inch stroke keeps it under control just fine.

If it were me, I would just drive as-is with thicker oil and then save my money to build a different (read that as bigger cubic inch) engine for a future swap if you want more power. Until then enjoy driving the truck.

 

A buddy has a 37 and I have 35 Ford with 283's and powerglides. We just did a 700mile trip with several other Rods and were all buying fuel at the same time. The others were mostly running 350's W/350's or 700R4's. All Newer engines.

We'd put in like 5 &6 gallons and the others were 9 to 11 gal. I was getting around 20 mpg and he would beat me with his taller gears at around 24 or so.
We were running 75/80mph and had stuff and a p***enger with us.

Mine has an Edelbrock Cam(mild) 600cfm carb and a old streetsweeper manifold.
Cool little engines....

 

That's one of the reasons I got this thing going...I have a big block dually that gets TERRIBLE mileage, and I knew this thing should at least get 15mpg or so. It does really good on gas. No ODO, so it's hard to tell, but I only put gas in about every 2 weeks right now.

 

****, Ridgecrest, You are right near me!

 

Well, changed to 20-50 oil....helped some, but not a ton.
It idles about 15psi, 35mph is about 20-25psi, and is around 40psi at around 60-65mph.
Better for sure, but not like my other cars.
So here's the dilemma......should I put the cam I have in it and run it like it is for now? If I gotta pull the motor out to do bearings, I'll end up doing the entire motor....better heads, pistons/rings, etc.
Really don't feel like a full rebuild right now, but I could do the cam and intake in a day.

 

I could be wrong, but I think that if you put the cam and intake on and continue to drive it as is, you'll be looking at a rebuild sooner rather than later, anyway. Just MHO.

 

I'de say you are probably right.
I'm thinking maybe put the intake on for the "look", and look for a 327 to build (don't want a 350....not the right time frame motor) and just take my time putting it together. Hmmmmmm..........

 

You want something like this:



I sold off the valve covers, intake and carbs to get some money together for my model A. Still have the engine, though. They're around.

 

Yea, that looks REAL good. I see you're in SoCal....I'll just swing by and pick that one up.

 

Good luck!! Band Aids are in the kitchen, garage, and bathroom.



Just kidding. Sent ya a PM.

 

I've always relied on the 10psi per 1000 rpm rule. It's just what I picked up from the old timers.