65 FI oil pressure problem

[Larry L.]

One comment is that I really don't care for the Icons. I reminds me of a Jap Juke box.

On to a serious problem.
Ran my 65 Fuel Engine on dyno two weeks ago and it ran fine the only problem was a bad capacitor in the distributor that started to make the engine miss fire at 5200 and above. Put in old Delco part and the problem was over.
The only thing I had to change on the Injector that John DeGregory restored for me was to richen up the power stop I turn. It made 365 HP at 6,500 and a bit more torque than factory spec. and it came up to max power at 5,200 and stayed flat to 6,300. Torque came up to 360 at 3800 and stayed flat to almost 5800.
That was the good news.
Engine break in was 6 hr at 2,000 to 2,200 up and down.

There is an oil seperator in the valley, it has a windage tray, 5 Qt pan, a Wix filter.
used a high volume oil pump and the oil pressure at 6,500 was almost a 100 psi. The rule of thumb is about 10 psi / 1000 RPM. The engine clearances are exactly as the service manual says.
It had the Comp Cams break in lube and 15 W 40 Rotella oil
After 6 hr of running and one power check we noticed the oil froth - blew it all over the dyno room. Changed the oil and filter and warmed it up and made another check. Still too much oil pressure. Pulled the pan and changed the oil pump back to the stock pump with high presure spring (55 PSI at 800 RPM Cold on 30 W) Reinstalled pan and ran another power check - The oil pressure is still above 90 but still a oil froth out the rear breather above 5200. If you take the cap off the fill tube you get more oil foam. The oil level after a run is still at the full mark on the dip stick. The dipstick was calibrated when we filled the engine with exacly 6 quarts and primed the engine. The dipstick read full.

Interanlly it has a 30-30 cam, piddle valve solid lifters, its balanced, crank cross drilled and oil holes champhered. Rod, Crank, piston clearances are at the loose end of the factory spec. It has roller rockers and full umbrella valve seals upstairs. Manly SS valves.
After the 6 Hr break in the plugs were checked and they were perfectly clean.
There are several choices as to what the problem is.
Some where high pressure oil is being sprayed.
Intake gasket slipped at installation of injector.
The oil separator in the valley is defective.
Oil is being picked up by the crank and thrown around.
The engine has no external oil or water leask.

Has nayone experience this problem or have a good guess as to what the problem may be.
We checked the oil pressure gauge and it agrees with a calibrated gauge.

[Mike M.]

Re: 65 FI oil pressure problem

I would try the stock oil pump with the stock spring not the high pressure spring.

[William C.]

Re: 65 FI oil pressure problem

I'm somewhat curious as the the "5 quart pan" reference in your post. If you are using the correct FI pan it is usually referrred to as a "6 quart pan" including the quart in the oil filter. If the pan is too small, with 6 quarts you will most certainly have the crank frothing the oil. It also sounds like the pressure relief valve is not working correctly in your pump. I'd look at replacing the entire pump with a non high-pressure non-high volume pump, and leave it at that. There are several post in the archives that discuss oil pump applications in great depth, but as a general summary, more is not better.

[John C.]

Re: 65 FI oil pressure problem

I agree with Mr. Clupper's post and for an excellent article on modifications to a stock oil pump, look here:
http://www.gofastnews.com/board/tech...ower-mods.html

[Duke W.]

Re: 65 FI oil pressure problem

I agree with Bill - buy a new oil pump, but since your car originally had the 55-60 psi spring that's the one I would recommend installing. You can get a correct OE replacement from NAPA (Clevite brand) or Federal Mogul Sealed Power.

Oil ingestion through PCV systems is a common problem, including some late model Corvettes, especially if the engine is run at sustained high revs. Was the dyno an inertia type or did RPM have to be stabilized at each data point to take a reading? If so, it may not be a problem in normal road use.

From the information you provided, I assume that the test was conducted on a Laboratory dyno.

1. Was the observed data corrected to standard sea level conditions?

2. What was the exhaust system configuration? OE manifolds or headers? Pipes? Mufflers?

3. What pistons are installed and were all the requiste measurments taken and run through a CR calculator to accurately calculate the CR.

4.. What was the front end accessory configuration?

5. Was any work done to the heads, adaptor plate, manifold, or throttle body to improve flow, and do you have any flow data?

6. At what RPM on the low end did the engine achieve 80 percent of peak torque.

If you can scan and post some data sheets or data curves that would be great.

Duke

[Larry L.]

Re: 65 FI oil pressure problem

For the pan guys - Stock pan is 4 qt + 1 with filter. High Performance is 5 qt pan + 1 in filter for 6 quarts. There is no such thing as a 7 qt system on a Chevrolet.

While we had the engine on the dyno - I pulled the pan and put in a new std volume oil pump, checked the relief pressure on test fixture I run on a variable speed mill. The releif pressure was 55 lb. After I put it back on the car it dropped the pressure from full peg, what ever that was, to 80 lb hot after two pulls. To reduce spark chatter we put two releif groves from pump gear center to outer edge to balance the pressure across the gears. As always the pick up tube was welded to the pump housing in three places.

The exhaust sysem could not be used because of the limited space behind the dyno. A set of 1 5/8 - 4 into one tube headers were used mainly because we needed to look at all 8 EGT's separately. This is a good indication of mixture distribution and how well the nozzles match.

I have to confess that I ported the heads using the information I got from the Smoky Yunick" book years ago. I dyed the first port with lay out dye, using a depth mike and special insert I scribed a circumfrence every 1/4 In down the port. Calculated the Area at each scribed line and generated a plot for the areas. I then caluculated the convergent nozzle areas and calculated the material I had to remove at each scribed line and then smoothed the outline. At each stage I checked the air flow on my homemade flow bench to see it was moving in the right direction. You have to check it often or you scrap a head. The manifold gasket was used to determine the beginning shape and area. The Injector plenum and manifold was measured and they were in perfect alignment. When it was all boted together you can see the gasket but cannot feel it. The divergence is at the valve seat. A lot of metal was removed to make the bowel work. The critical area is on the bottom of the runner as it turns into the bowel. This radias needs to be made clean. The other area that had the most effect on flow was the square section next to the head bolt. Then the area adjacent to the push rod. Once you have one port working - your have to copy it 7 more times. The total labor hours was 40 +.

The block was never align borred or decked so we have a reasonable amount of piston head clearance.

The TRW pistons had a number of sharp edges and each piston was smoothed. To balance the engine we found the ligthest piston and took a cut off the bottom of the other piston skirts as necessary.

The engine bore is 0.061 over because some one messed up over bore the first time. We honed the block with a torque plate. The pistons were 0.062 over and we took a little off of them to make sure the piston / bore diameter was exactly as spec. at the tdc, midway, and bdc

The combustion chambers were smooted a little and some materila removed where the factory fly cut for valve releif was made. Each head was scribed for 4.061 circle centered around cylinder. The overhang was smoothed to help reduce the CR. Finally each combustion chamber was CC'd and a compression ratio was determined to 11.15.
With out the combustion chamber work the CR was 11.22. We were shooting for 11 but it required too much metal removal. I wrote my own program for calculatting the CR - its written in "C" and runs on a Unix system. The actual measurement was very close to the calculation. The guys at Performance Clinic were amazed at how accurate it was.

The porting of the heads is different for a FI engine than a Carb because the air flow in a carb is horizontal and then is bent down, while the FI air flow is down and then bends into the ports. In a carberated engine the floor is the low flow area and in the fuel the floor flows a lot more. My older brother made me a set of miniture pito tubes so we could measure flow anywhere in the port.

The heads were treated to a nice 3 angle valve job and all of the angles faired together

The valves were Manley high temperature with a swirl polish.

Exhaust ports were enlarged and the stock exit shape was retained and flow matched to a nice set of 2.5" manilolds to be used on the car. The maifolds were opened up about 1/16 bigger than the ports and polished on the inside.

The head gaskets are a set of NOS steel gaskets from 1965. They were trimmed to make sure they did not over hang the bores. The thickness was 0.018 if I remember correctly.

I will will publish the plots in a few days. The volumetric effiency was interesting to as it peaked from 80 % to 89% at 5,000.

The cam is a Crane restoration cam a replacement for the 30 / 30. The lift as measured on a surface plate was 0.004". You have to measure the lobe profle. I have the lobe profile and wanted to compare it to an orig. came profile but I have yet to find an orig cam that was not worn.

The oil pressure and foam are a serious problem because the crankcase vent tube connects in to the intake air filter adapter and a slug of oil foam wold put the fire out or case a big puff of smoke. The oil quantity is equivalent to 2 table spoons when you let it set.

We are still looking for a solution.

[Larry L.]

Re: 65 FI oil pressure problem

The engine was run on a dyno at Engine shop, The dyno had been reciently calibrated but still had some issues with EGT variations during calibration. A new set TC probes and bungs are on order. Then the EGT will be calibrated.

All data was corrected to standard day.

Oil pumps in all cases were new and tested for pressure releif.

The orig. adapter plate was replaced with an NOS one. The fit of new NOS manifold was perfect and no rework was required,

The stock plenum was untouched as it mated to the manifold perfectly.

Additonal information:
After the pan was pulled and the pump replaced with std. volume pump we drained the oil,
changed the filter, and only put 5 qts back in so we should have been well below the windage tray.

The cankcase pressure is normally a low pressure as the fitting in the front of the plenum has a 0.090 orfice and should be able to handle normal blow by.
We put a rag into the front fill tube and into the rear breather and both were blown out along with oil and foam. Everything is perfect below 5200

Duke:
From your experience is the HP in line with this engine or should it have a higher output? I was looking at some early Chevrolet dyo plots and the shap does not look anything like the HP and Torque shapes I have seen.

[Duke W.]

Re: 65 FI oil pressure problem

Thanks for the detailed rundown. You did a good job. If you can post actual head flow data that would be great as flow is critical to how much power can be achieved.

A few years ago Dave McDufford rebuilt his '65 L-79 to my SHP recommendations. This included pocket porting/port matching the heads with multiangle valve seats IAW generally accepted methods that have been in publication for over 30 years and the LT-1 cam. Everything else was OE or OE equivalent. The measured CR averaged 10.35:1 in a narrow range with a .026" composition gasket. It operates detonation free on premium unleaded with a "normal" spark advance map.

He spent two days testing his engine on a lab dyno (including sorting out a number of carb and ignition problems.) The engine was tested with both a set of admittedly shabby looking dyno headers and the OE 2.5" manifolds with the front OE pipe section, both with large exhaust pipes as required to route exhaust gas out of the dyno cell and no mufflers. No fan was installed and an electric water pump was used. The tests were conducted with high octane leaded race gas to preclude any possibility of detonation.

The headers improved peak torque by about 6 percent, but yielded less than 2 percent more top end power. Installed in the car the difference would likely be less because even the modest estimated 3 psi max exhaust pressure of the 2.5" exhaust system will negate much of the favorable wave dynamics generated by the headers.

The following are his best peak numbers. Observed data was corrected to standard sea level conditions, so the presented data is equivalent to SAE gross. The best power runs were done with 41 degrees total spark advance.

With OE manifolds 338 lb-ft @ 4400, 356 HP @ 6400
With headers 358 lb-ft @ 4500, 362 HP @ 6500

80 percent peak torque with manifolds was achieved at 1600 and did not increase significantly until 2500 with a steep rise between 3000 and 4000. This torque characteristic is typical of SHP engines. Another virtually identically configured engine on a chassis dyno achieved 80 percent peak torque at 2100 and 90 percent at 2500. I can't explain the difference.

Dave's original 461 heads flowed very nicely after rework with 236/191 CFM at 0.5" lift, 28" H2O depression. (The actual flow test was done at 25", but I converted the data to 28" since this is a more common test depression.)

IMO the limiting factor of Dave's engine is the 327 SHP manifold. I would expect FI to make more power on the same long block, but less low end torque. Your power is similar, but the torque peak is sooner, which is why I am very interested in the low end torque and would like to see the torque values at the lowest speed tested and hope it was no less than 2000. Simulations indicated virtually no difference in peak power between the 30-30 and LT-1 cams, but the LT-1 cam showed better low end torque. The objective was 80 percent at no more than 2000. Engine ****yser 3.0 was quite accurate in its top end power prediction, but predicted peak torque with manifolds was the same as observed with headers. The good news was that actual measured torque at 2000 was about 20 percent higher than EA predicted and even higher than the 1500 prediction.

Dave's test was done on an inertia dyno at 300 revs/sec/sec acceleration, so the engine did not spend much time at very high revs, and I don't recall that he reported any oil ingestion problems.

What kind of dyno was used for your tests - steady state or inertia. As long as you don't run sustained revs above 5000 in normal use I don't think oil ingestion will be a problem with the engine in the car.

I know Dave is around, and now that we can post attachments to the board, maybe he can dig up his composite dyno sheet and post it.

Also, based on various dyno test data I have in the file from various sources the true SAE gross HP of these SHP/FI engines with as-built heads is in the range of 300-330 HP. The head rework is what gets them in the ballpark of the advertised gross HP rating. Torque was also overrated by about ten percent. Head work has little effect on peak torque, but headers improve peak torque - at least in a dyno cell with no mufflers

Duke

PS. Well that's interesting! Apparently the Board has an electronic sensor that replaced the A-n-a-l of Engine A-n-a-l-y-z-e-r with ****

Come on! That's just stupid!

[Clem Z.]

Re: 65 FI oil pressure problem

if the windage tray is not designed to operate with the oil pan you are using the oil may not be draining back into the pan fast enough and getting caught in the rotating assy causing the foaming. the pan and the tray MUST have been designed to operate together.

[Larry L.]

Re: 65 FI oil pressure problem

Unfortunately we were a little late turning on the "start data collection" button and the reading started at 3700.

We ran the stock water pump with stock pulleys and idler.

The initial advance was 19 deg and was limited to 38 deg by stock distributor. With this compression ratio any more advance and you are in danger of blowing head gaskets.

We ran 100 Octane low lead Av Gas (100 octane lean and 115 octane rich).

The pan is a factory 5 Qt and the windage tray came with the engine and is a stock windage tray. All of the components were checked for size and fit before assembly. A retired doctor I know had a spare bore scope - I was able to look inside the assembly threw the oil pan drain plug to make sure we had proper clearances. The thing I was concerned about was the pump bypass to pan wall clearance. With the high volume pump it almost touched we removed the pan while on engine was on the stand and cut the pump cover back so we had about a 1/4 in between end of pump and pan wall. The standard pump was just measured and it was pretty close to modified high volume pump size.
If you ever install a high volume pump look out for this one.
The windage tray fit the pan pretty well. Its hard to judge distance with only one eye.

I have the plots done and will put them on company web site - you can down load them and view them as a .pdf file. The files are just too big. This way we have all the detail.

One thing that was interesting was the torque was almost flat from 3,700 to 6,000 and only fell off to 288 at 6,500.

The dyno pulls were long as we were looking for trends or steady state data and not fast transient data. Such as real EGT. They had a lot more scatter than it should. The TC calibration should be complete in a few days and I will correct the data and post it. This is a good way to compare nozzle flow rates or look for other fuel/air distribution problems.

I don't think I am going spend years on the restoration of the 65 Nasau Blue Coupe and go out and redline it wihen the restoration is done.

You never know -
What happoned on the way the last MVC Judging meet was a hoot. It 6:30 AM and two of us stopped at a trffice light just before the homeless shelter. My 66 350 /327 and a 63 340/327. There were a lot of people headed over for the free vittles. We looked around and no cruisers in sight. The light changed and we were near redline in 3rd. before we shut it down. With the top down you could hear the homeless shouting, cheering, jumping up and down.

So much for old hardware.

[Duke W.]

Re: 65 FI oil pressure problem

Be sure to come back and give us the link to the website.

Improving head flow is why the torque curve stays fairly flat past the peak. The engine nearly identical to Dave's that was tested on a chassis dyno to 7250 showed a very mild torque drop past the peak and a very flat power curve from 5500-7000 even though it was tested on a hot day with no external fan and the clutch fan was "locked and screaming", which was probably costing 15 HP at the flywheel.

There was a little more rolloff beyond 7000 then it really started to drop at 7200, which was either the heads being choked or the beginning of false valve motion, or some combination of both.

Just to remind everyone, again, if you ever do a dyno test - lab, chassis, whatever, start at least one pull at 1500 unless it's a racing engine that is never asked to run below 3000.

Duke

[Larry L.]

Re: 65 FI oil pressure problem

1965 FI Dyno Plots and video of dyo runs are now available.
Point your brouser to:

http://www.micro-controls.com/Corvettes/Y65/

The .pdf is the 3 plots showing HP Torque etc.
2nd plot is volumetric effencey, 3rd is EGT before we finished calibration and has a lot of data scater.
.*.sg2 is movie of dyno runs.
While you are at it is you step back a directory to Y66 you can see my 57, first 66, and current 41K mile 66 roadster orig paint etc. I have owned the car for 39 years.