Diagnosis ?

by wunderlich_33 Wed Mar 25, 2015 11:19 am

So im having two issues with the vehicle and no one seems to be very helpful, so I figured id give the experts a go Wink

Issue #1: when I put my foot to the floor there is a power delay/bog.
Notes: the timing is perfect, the squirter in the carb was upgraded with nozzels, it has the stock 2:56 gear in the rear end. the air fuel mixture is fine and so is the idle.

Issue #2: Im getting a oil spray on my engine. Its spraying upward and hitting the bottom of the air filter on the left side of the engine, the intake is getting covered aswell and theres some spray on the valve covers.

I cannot find the source of the problem because its only when im flooring it and the car is under heavy load. if I am driving it normally and the the oil pressure stays between 53 and 63 theres no spray. but Im afraid if I try to rev it high enough to see the issue while its in park that ill blow my engine,

so .... help... please?

by Joe73 Wed Mar 25, 2015 11:28 am

Regarding issue #1. Small block or big block??

What kind of carb? Vacuum or mechanical secondaries? If vacuum, do you have colored springs to adjust?

What is perfect timing? What is the initial and the mechanical? Are you using a vacuum advance (which you should on the street)? How much vacuum advance is the can pulling? If your using a vacuum advance, is it one full or ported vacuum?

Initial timing should be around 12-16 degrees. Vacuum advance should be around 10-12 degrees and mechanical should be around 10-12 degrees. Your looking for a total advance (initial + mechanical + vacuum) of 34-38 degrees for a small block.

by thatfnthing Wed Mar 25, 2015 11:41 am

For issue #2: Do you have just breathers on the valve covers, or do you have a complete PCV system? Any visible cracks in the valve covers? And just so we're on the same page, 'left' is the driver's side of the engine, yes?

by wunderlich_33 Wed Mar 25, 2015 11:50 am

It is a small block 383 stroker bored .040
600 holly vacuum secondary
donno about the springs or the technical carb stuff ( just got the car two years ago , still learning )
I think its full vacuum.

the timing is 35 on the nose.

[img] Diagnosis ? 10685610

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yes drivers side, no cracks they were barely used

by Joe73 Wed Mar 25, 2015 12:10 pm

Does your distributor have a can on the side of it with a hose coming off the front of the can? If so, look where the hose goes to. If its on a carb port at the base of the carb then its full vacuum. If its above the base of the carb its ported vacuum.

35 degrees is a good number. But how are you getting there? What is your timing at idle with the vacuum advance disconnected and plugged if you have one? If you have a vacuum advance, is it adjustable?

You have either a timing or carb issue. Timing issues will take longer to figure out.

If you get your timing into the parameters I described you will have a nice crisp throttle response.

Since everything is running good for you, why not just buy a holley vacuum secondary spring kit? They're real cheap and color coded. Just open yours up, see what color you have and install the next "stiffer" spring.

by wunderlich_33 Wed Mar 25, 2015 12:15 pm

I will have to check it out when I get home.

yeah im not sure how im getting there, I had the car sent away to have the engine built last summer. it came back and still needed a lot.

I do believe my vaccum advance is adjustable.
ill definitely look into the spring kits.

by thatfnthing Wed Mar 25, 2015 12:22 pm

I assume the PCV valve is functioning properly. What's on the right side valve cover? A hose to the air cleaner, or just a breather? When the 'spray' happens, is the valve cover around the PCV valve wet also?

by wunderlich_33 Wed Mar 25, 2015 12:27 pm

yes it seems fine, there should be a hose to the air cleaner but we blocked it off.
the spray is more towards the rear of the engine, but I will double check the second I get the oppertunity

by Joe73 Wed Mar 25, 2015 12:32 pm

You also need to take a vacuum reading of the engine at idle. If that doesnt match the vacuum advance can (if you have one) your advance might not be coming in or leaving at the right time.

After you get the vacuum reading of the engine you need to put a hand held vacuum pump on the advace can (again if you have one like you should on a street car) and see when the can is "coming in". and by how much.

by bracketchev1221 Wed Mar 25, 2015 12:48 pm

wunderlich_33 wrote:yes it seems fine, there should be a hose to the air cleaner but we blocked it off.
the spray is more towards the rear of the engine, but I will double check the second I get the oppertunity

The hose should be open. With a PCV system, the intake manifold pulls a slight vacuum on the crankcase. Under normal conditions the PCV is the exit for air out of the engine, and the "hose" would be the vent path for air into the engine. Under hard acceleration if there is excessive crankcase pressure, the hose can let gases out of the engine as well. So you need to have some kind of breather in the place of the hose.

As far as your timing, I suggest eliminating the vacuum advance for now. A well tuned engine will "benefit" from vacuum advance, but it is not needed to run. So you should be able to make it run clean without the vacuum advance first and eliminate 1 variable. Set the initial timing in the 12-18 range, and your total at 34-36. I like as much initial as the car can handle. Sometimes starters don't agree with it when hot. After that, see if it gets better. Next will be to look at the carburetor accelerator pump. Make sure you just have the slightest amount of play between the lever and the pump arm at idle. See how it goes from there.

by thatfnthing Wed Mar 25, 2015 12:59 pm

The PCV system has two sides: a hose from the air cleaner (or breather) to one valve cover to let in fresh air, and a PCV valve and hose from the other to the carb base or manifold to suck in crankcase vapors and burn them. If you only have the suction side, there's no fresh air coming in. Further, when you put your foot in it, positive pressure builds up in the crankcase with nowhere to go, so it will force oil out anywhere it can -- weak gaskets, cracks, PCV valve seal, etc. In my case, it fired the dipstick right out of the tube. You can put a baffled breather on the other valve cover and this should alleviate most of the problem, but if you put your foot in it a lot, you'll probably want to get an oil recovery tank, as a baffled breather will only baffle so much.

by wunderlich_33 Wed Mar 25, 2015 2:09 pm

This is awesome guys, thank you so much for all the help.
ill see what I can do and let everyone know how it goes, but don't let that stop the ideas.

by fishhead Wed Mar 25, 2015 3:05 pm

Definitely no expert here but the fitting that plumbs into the back of your engine block for your oil pressure gauge comes to mind,especially if you have the nylon tube feeder thats prone to cracking.The intake manifold gasket in the rear can sometimes not seal good during installation.There's the distributor gasket to think about.I had a leaky valve cover gasket once that was actually hard to spot because of the fan blowing oil every direction so I just had to park it and start with a clean motor and plenty of bright light to find the source of it.All my experience is with pre-80's chevy smallblocks.

by 77mali Wed Mar 25, 2015 5:25 pm

As mentioned, double check your valve cover gaskets & make sure they are properly aligned & that your center bolts are not over torqued. When they are, they have a tendency to spit out some oil up top. If there is a big enough gap between any portion of the valve cover & gasket oil will spray out there as well.

Check your Vac lines including the lines for the transmission that connect to the intake manifold. If they're not secured properly or are damaged they could also be the source of your lag issue.

by dynchel Wed Mar 25, 2015 7:04 pm

I had oil blow by from using a auto zone pcv breather. Apparently it was ineffective at venting the crank case. A oil cap breather on one side and a normal pcv on the other fixed it.

by wunderlich_33 Thu Mar 26, 2015 8:10 am

Its amazing that stuff as tiny as a breather cap can cause issues.

the guy who built my engine was a spaz. I didn't know it before hand but definitely found out along the way.
he told me it was fine to have it blocked off like that. when he hooked up the tranny he never put a gasket in the detent cable, he didn't have a throttle braket so he told me it was okay to run the car without the dentent without issues, he zip-tied all my ingintion wires together, put the distributor in on the wrong tooth but instead of redoing it adjusted the wire positions so they were proper, among 50 other things.....
worst...... upon installation of the engine he dropped the damn thing from the cherry picker 4 inches away from my cars fender and bent my crankshaft and split my balancer in half.`
it was 6 months of this crap...

by Joe73 Thu Mar 26, 2015 8:16 am

Wire positions do not matter. As long as you set #1 where you want it and you follkw the firing order.

by wunderlich_33 Thu Mar 26, 2015 3:45 pm

well I went out and got the baffled breather like a few suggested and then im gonna adjust the air mixture again, maybe im leaning out.......

sadly there really isn't a set science to these cars, but then again the tinkering is half the fun ^^ ( up to a certain point of course, then you just start getting mad lol)

by pila Thu Mar 26, 2015 5:48 pm

Don't get mad......get even ! Fix it ! Very Happy

by wunderlich_33 Thu Mar 26, 2015 6:16 pm

thatfnthing wrote:The PCV system has two sides: a hose from the air cleaner (or breather) to one valve cover to let in fresh air, and a PCV valve and hose from the other to the carb base or manifold to suck in crankcase vapors and burn them. If you only have the suction side, there's no fresh air coming in. Further, when you put your foot in it, positive pressure builds up in the crankcase with nowhere to go, so it will force oil out anywhere it can -- weak gaskets, cracks, PCV valve seal, etc. In my case, it fired the dipstick right out of the tube. You can put a baffled breather on the other valve cover and this should alleviate most of the problem, but if you put your foot in it a lot, you'll probably want to get an oil recovery tank, as a baffled breather will only baffle so much.

I want you to know that you sir are a beautiful human being. lmfao.
first thing i did ( was the simplest and cheapest solution to try ) was go out and buy a baffled breather and installed it... and i went out, found a stretch, and put my foot down.... No More Bog!!!!
or if there is any its hardly noticeable. amazing how one cheap little part solves a huge issue.
that little bugger gets hot though found that out quick. lol
but thank you so much.

and thank you to everyone else that contributed , highly appreciated.

by bracketchev1221 Thu Mar 26, 2015 8:18 pm

Glad it worked out and it was simple.

by 77mali Thu Mar 26, 2015 8:44 pm

bracketchev1221 wrote:Glad it worked out and it was simple.

x2!

by thatfnthing Fri Mar 27, 2015 5:54 pm

Ray actually beat me to it, but I'm glad it worked for you! And if that guy was that big of a goof, I'd go back and double check everything he touched. He clearly didn't seem too particular about his work. Suspect

by wunderlich_33 Fri Mar 27, 2015 8:15 pm

thatfnthing wrote:Ray actually beat me to it, but I'm glad it worked for you! And if that guy was that big of a goof, I'd go back and double check everything he touched. He clearly didn't seem too particular about his work.

damn you guys even know each other by first names on here. lol.

i went back and looked and i did miss his message some how, but in any case thank you both.
like ive said, its frustrating playing with things and brain storming with mechanics and and being left scratching your head.

yeah he was something, i went over to work on it with him a few times and i saw why he kept asking for extensions, he would work for 10 min then run off for 20 come back, check what he did, put some tools away, run off again. he wasnt very focused. in 4 hours he did about 40 min work. and i had paid him in advance to start building it over winter so spring would be just n install and he said build and install would take only 2 weeks.
6 months later and all the car shows over i didnt give him a choice and worked under the hood for 3 days straight outside in the rain to finally bring her home and have been fixing things since.

but glad to have my baby back, and now that she wants to really go on take off i have to fix my traction issue by shoving a posi rear end in her.

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