OK, with more information we do have issues we need to deal with - zero oil pressure at idle and 15 minutes of white smoke at startup are indicative of real issues with the engine.

How does the oil look on the dipstick? First step is to change the oil and filter to ensure the PO didn't have some super-thin racing oil and screwy filter. If the pressure is still low...then it's decision time. I agree that the most likely cause are wide bearing clearances due to wear...and I also agree that while a HV pump may put a band-aid on it and bring the pressure up, if the bearing clearances are that wide we're going have problems sooner vs. later.

I'd continue on to doing a compression/leak-down test.

Not sure what your arrangement was with the PO - but if any representations were made as to the condition of the engine it's worth a discussion.

 

1. I went with a high volume pump but started developing oil leaks around the rear main seal. Went back to the standard pump and no more trouble. Youll pick up a few h.p. by going standard pump.

2. I went with an electric (quiet) Holley Pump, 125 gph, 7 psi , with no return. Works well plus you can splice in a hidden mini Kill Switch for theft control.

3. I went with a high torque mini Starter and wrapped it in a high temp. insulating blanket (except the ends) . Never any problem.

4. I couldnt live without a Tach. But its up to you. I have a Mallory 9000 electronic eye Distributor .

5. A 750 cfm carb will be ideal unless you are going to go hog wild on racing Heads and Cam . I REALLY like my 800 Mighty Demon Carb , dp, with mech. secs, and annular boosters for maximized low end torque ...and it made a tremendous difference over the 800 Edlebrock Carb. If you keep your old Holley 750, be sure and overhaul it and run SeaFoam cleaning agent thru the bowl vents and air vents of the Carb, regularly, while its running at idle.

6. If you want REALLY big power gains...go with Edelbrocks Oval Port ALum. Heads with AirGap dual plane intake (check your hood clearance first) -- I have an L88 hood so no problem . They flow so much more air and are high quality. I went with them and a Lunati hyd. roller cam 232/242 dur. @ .050" , 575/595 lift ......excellent for low and mid range torque especially . A bit lopey at idle but makes a nice rumpity-rump sound ... wish i would have gone a bit higher on the lift now as the lope isnt objectionable .

7. Yes :

a. If you want alot more low end torque then go with a carb which has annular boosters. In a car magazine a couple years ago, they tested the same Carb with and without Annulars and the one with Annulars made an astounding 90 ft.lbs. of torque more over DropLegs . Ive ran both, and i can feel the difference with Annulars.

b. If you dont really need a choke, then select a carb without a choke like a Holley HP4150 or Mighty Demon ... you get more air thru it but in cooler weather you may have to feather the gas pedal for the first 30 seconds after startup ; after that, it holds at 750 rpm cold and 900 warm.

c. Get your Distributor recurved if you want to maximize low end torque . I had mine done by a Tuner who did it on his bench and when i got the car back, if felt like an additional 100 hp and surprised the heck out of me.

According to Edelbrocks Dyno sheets for a 454 cid Motor (with Headers) , it comes in at 540 hp and 539 tq. ... but thats using their tamer Carb and tamer Cam. Based on other Dyno'd 454 buildups...I figure im currently at 560 hp and 600 tq. (1970 stock engine figures are 390 hp/500 tq) . The performance is phenominal -- to give you an idea, the rear wheels break loose in 3rd gear going WOT at just 2500 rpms. 1st and 2nd gears are near impossible. Im running BFG's 255x60's on all fours.

Good luck .

 

@Billa:I changed the oil when I got the car with 10w30 synthetic. This is what the pevious owner said he had been using. I noticed the low pressure then, talked to a mechanic who suggested a heavier weight. I chaned oil again and went with a 40w. Pressure got a little better but nothing close to what Ive read to be normal. The oil looks very clean, the oil in my accord is darker than in my vette.
As far as the PO being any help... lets just call this a life lesson!

@ThecallmeDave: Nice post, a lot of good info there, if it turns out I have to do a rebuild I ll definitely follow your advice.

Thanks again!

 

Rats. Well - no easy answers on the oil pressure. You'll have to decide if you're just going to let it ride or try the HV pump swap...but honestly, I don't think the engine has a lot of life left in it.

Let's get the compression/leak-down info and go from there...

 

@billa: Father-n-law and I are going to work on that this weekend. Once I have the numbers Ill post them and see what you all think.

 

HV pump or HP pump? I thought the risk of sucking the pan dry was with a HV pump. Or is that just web bs?

 

HV pumps are in almost every circumstance a bad idea. They don't suck the pan dry, because they can't actually move high volumes of oil through typical clearances.

HV pumps came out of two things - racing teams that were experimenting with very wide bearing clearances, and as a means to increase oil pressure in engines with worn bearings. Racing teams abandonded the wide bearing clearance approach as it didn't work.

So - generally a big NO to HV pumps since they end up in continuous bypass and take a bit more power to spin. But in this case with zero oil pressure at idle...it might be a workable band-aid.

 

If the engine is running as badly as it seems to be from your description, a good stock rebuild might give you all the power you are looking for. We're talking a BIG engine here at 454 ci!

Pete

 

http://forums.corvetteforum.com/pict...ictureid=93759

 

Im trying my best to upload pics of heads but computer is winning this battle!

 

 

 

 

Notice in this pic the bolt head with the BPG, Is this a factory bolt? I wouldnt think it is. Maybe some work has been done to this engine in the past.

 

Overall what do you think of pics? Any noticeable things i should be concerned with? To my untrained eye it doesnt look that bad!

 

Those are 1974, 781 large oval port heads. Good heads. They've definitely been off of there before.

I see you already have headers. That's good.

Looks like you might be running a carb adapter to mate that Holley to your Q-jet manifold. That's bad. Horsepower killer. Either go back to a Q-jet or switch to a square flange intake.

 

Does anyone know what the BPG stamped on the cyclinder head bolt stands for?

 

Pretty tough to tell much from pictures, other than as noted the engine has been apart to some extent, at least the top-end.

 

Hard to discern much with the naked eye. Need to get those compression/leak-down numbers to evaluate the engine's general health from the outside.

BPG might have been from Butler Performance back in the day, but that's a bit of a WAG.

 

Okay so it took me several attempts before I could find TDC but finally did and here are my results for cylinder leakage test:
Cylinder#
1.30%
2.35%
3.32%
4.32%
5.26%
6.30%
7.38%
8.32%

All cylinders were tested cold,with a hf tester it would not reach 100 psi. It had two gauges on the right psi gauge left % loss gauge. When zero out psi gauge only read about 15psi. Hope this doesnt have a major affect on the out come. No noise from exhaust, no bubbles in coolant, no noise from carb, no noise from dipstick.

Thanks!

I havent done a comperssion test yet, do you think it is still needed?
What do you think about numbers?