Hey all! I recently bought an 89 Lx 347 stroker car that my buddy built 10 years ago. I've had my eye on the car for years and finally got it for 4K but the issue is after he built it the car seems to intermittently smoke/burn oil and has a rattle/tap noise from the top end and he literally was so frustrated that he never even tried to break it in and parked it. I've attached a mod list and I'm considering buying a stock low mileage 302 and just swapping all of the aftermarket parts to it but I'm wondering if the x303 cam and dart heads will work on a stock 302 as far as valve clearance? Any help would be great!!!
New To The Site And Need Some Help!
- Thread starter Cody Tigges
- Start date
-
Sponsors (?)
Hey Cody, welcome to Stangnet.
So you're saying that the engine has very low mileage on the rebuild? You might consider fixing it yourself.
Most, if not all parts would swap over. Can't say positively about the ptv clearance. You would want to check that if you swapped to a new block anyhow.
I'll move your thread to the '79-'95 General Talk subforum. That's where us fox guys hang out. We have some serious gearheads here that'll be able to help you out no matter which way you decide to go.
I'm a paint and body guy if you ever need help in that area.
It's good to have you with us.
So you're saying that the engine has very low mileage on the rebuild? You might consider fixing it yourself.
Most, if not all parts would swap over. Can't say positively about the ptv clearance. You would want to check that if you swapped to a new block anyhow.
I'll move your thread to the '79-'95 General Talk subforum. That's where us fox guys hang out. We have some serious gearheads here that'll be able to help you out no matter which way you decide to go.
I'm a paint and body guy if you ever need help in that area.
It's good to have you with us.
Good morning.
Let's start with the basics to see if that engine is healthy, no reason to assume the worst. Let's do a compression test followed by a leakdown test, these will tell us how much life is left in the current setup. You will need to either buy or rent a compression/leakdown tester from a local auto parts store, many of them will have this available for rent. The leakdown test will require compressed air do you have a compressor?
If you can't find the quick and dirty on "how to" from Google I'm sure one of us can do a quick writeup for you.
Oh and Welcome to
Let's start with the basics to see if that engine is healthy, no reason to assume the worst. Let's do a compression test followed by a leakdown test, these will tell us how much life is left in the current setup. You will need to either buy or rent a compression/leakdown tester from a local auto parts store, many of them will have this available for rent. The leakdown test will require compressed air do you have a compressor?
If you can't find the quick and dirty on "how to" from Google I'm sure one of us can do a quick writeup for you.
Oh and Welcome to
Only use a compression tester with a screw in adapter for the spark plug hole. The other type leaks too much to get an accurate reading. Your local auto parts store may have a compression tester to rent. If you do mechanic work on your own car on a regular basis, it would be a good tool to add to your collection.
With the engine warmed up, remove all spark plugs and prop the throttle wide open with a plastic screwdriver handle between the throttle butterfly and the throttle housing. Crank the engine until it the gage reading stops increasing. On a cold engine, it will be hard to tell what's good & what's not. Some of the recent posts have numbers ranging from 140-170 PSI. If the compression is low, squirt some oil in the cylinder and do it again – if it comes up, the rings are worn. There should be no more than 10% difference between cylinders. Use a blow down leak test (puts compressed air inside cylinders) on cylinders that have more than 10% difference.
I generally use a big screwdriver handle stuck in the TB between the butterfly and the TB to prop the throttle open. The plastic is soft enough that it won't damage anything and won't get sucked down the intake either.
A battery charger (not the trickle type) is a good thing to have if you haven't driven the car lately or if you have any doubts about the battery's health. Connect it up while you are cranking the engine and it will help keep the starter cranking at a consistent speed from the first cylinder tested to the last cylinder.
With the engine warmed up, remove all spark plugs and prop the throttle wide open with a plastic screwdriver handle between the throttle butterfly and the throttle housing. Crank the engine until it the gage reading stops increasing. On a cold engine, it will be hard to tell what's good & what's not. Some of the recent posts have numbers ranging from 140-170 PSI. If the compression is low, squirt some oil in the cylinder and do it again – if it comes up, the rings are worn. There should be no more than 10% difference between cylinders. Use a blow down leak test (puts compressed air inside cylinders) on cylinders that have more than 10% difference.
I generally use a big screwdriver handle stuck in the TB between the butterfly and the TB to prop the throttle open. The plastic is soft enough that it won't damage anything and won't get sucked down the intake either.
A battery charger (not the trickle type) is a good thing to have if you haven't driven the car lately or if you have any doubts about the battery's health. Connect it up while you are cranking the engine and it will help keep the starter cranking at a consistent speed from the first cylinder tested to the last cylinder.
Attachments
Hey all thanks for the replies!!! I should have been a little more specific but wasn't quite sure how to make a post when I made this yesterday. The car has less the 150 miles on it since rebuild but it sat for 10 years. So far I have replaced the spark plugs, done a compression test (all good), drained fuel tank and replaced with 91, checked timing, changed all fluids, checked my intake to make sure pcv wasn't sucking oil, etc. I also pulled the valve covers are re-torqued my rockers. Only thing I haven't done is a leak down test (I'm an auto tech and have full use of a shop so I have any tool at my disposal) I did pull the plugs again though and they appear to be black and oil soaked so I'm thinking maybe he put the rings in wrong?
It will take some time and miles for the rings to seat. Avoid synthetic oil during the break in process and use the lubricant recommended by the builder or ring manufacturer. If your compression test was good, then the odds of the rings being installed incorrectly are small.
A blow down test as I described will give more accurate results on the state of the sealing of the rings. See my post above on how to build your own blow down tester.
A blow down test as I described will give more accurate results on the state of the sealing of the rings. See my post above on how to build your own blow down tester.
Seems like you've gotten some good advice so far with your cylinder issues. I have a couple comments about some other things that seem out of whack or a concern.
1) Proper cylinder heads for a 347 stroker would be too much for a little 302 to swap over to.
2) 93' Cobra computer and injectors? I think they had 24# injectors which would be way too small for your combo, you'd need 42# injectors IMO
3) Hopefully you have at least a 255lph fuel pump and you replaced the fuel filter and fuel pump sock while changing out the gas.
3) Get an oil filler cap and remove the "breather" filter from the valve cover. That setup is for boosted applications.
1) Proper cylinder heads for a 347 stroker would be too much for a little 302 to swap over to.
2) 93' Cobra computer and injectors? I think they had 24# injectors which would be way too small for your combo, you'd need 42# injectors IMO
3) Hopefully you have at least a 255lph fuel pump and you replaced the fuel filter and fuel pump sock while changing out the gas.
3) Get an oil filler cap and remove the "breather" filter from the valve cover. That setup is for boosted applications.
One other thing ...that intake manifold is crap. They are a fire hazard and don't perform well among other issues. Swap that out to either an Edelbrock rpm II or a Holley Systemax.
42 Lb. injectors ? Don't just spit things out, do the math...
Fuel injector sizing & injector photos
Revised 26-Dec-2014 to add statement about figures are for flywheel HP and not rear wheel HP
Injector HP ratings: this flywheel HP, not rear wheel HP.
Divide flow rating by.5 and multiply the result by the number of injectors. This uses a 100% duty cycle. These ratings are for naturally aspirated engines at the flywheel.
Example:
19/.5 = 38, 38 x 8 = 304 HP
24/.5 = 48, 48 x 8 = 384 HP
30/.5 = 60, 60 x 8 = 480 HP
36/.5 = 72, 72 x 8 = 576 HP
42/.5 = 84, 84 x 8 = 672 HP
The preferred duty cycle is about 85% maximum, so for a safety factor multiply the final figure times .85.
19/.5 = 38, 38 x 8 = 304 HP x .85 = 258 HP
24/.5 = 48, 48 x 8 = 384 HP x .85 = 326 HP
30/.5 = 60, 60 x 8 = 480 HP x .85 = 408 HP
36/.5 = 72, 72 x 8 = 576 HP x .85 = 490 HP
42/.5 = 84, 84 x 8 = 672 HP x .85 = 571 HP
Remember that the above ratings are at 39 PSI. Increasing the pressure will effectively increase the flow rating. Example: a 19 lb injector will flow 24 lbs at 63 PSI, and a 24 lb injector will flow 30 lbs at 63 PSI.
See http://users.erols.com/srweiss/calcpchg.htm to get the calculators used in these examples.
Here's the duty cycle explanation. Duty cycle is how much of the time the intake is open the injectors are turned on. The 85% figure means that for 85% of the time the intake valve is open, the injectors are spraying. The idea is that you want some percentage of the duty cycle left over so that you have some room to grow the process.
If you are at 100% and you need more fuel, all you can do is turn up the fuel pressure. That means the whole fuel curve from idle to WOT is affected. Maybe you are already too rich at idle, and turning up the fuel pressure makes it worse. If you had some injector duty cycle left to play with, a custom tune could use that where it is needed. That would not over richen the whole range from idle to WOT.
If you did turn up the fuel pressure, you might be able to change the injector duty cycle to get the air/fuel mixture ratio you want since the injectors will have extra fuel delivery capability.
With larger than stock injectors or higher that stock fuel pressure, you will need an aftermarket MAF that matches the injector size. The MAF “lies” to the computer to get a fuel delivery schedule that meets the engine’s needs and isn’t too rich or too lean. The best strategy is an aftermarket MAF and a custom tune to insure the best air/fuel ratio over all the RPM range.
Don't forget to increase the fuel pump size when you increase injector size or significantly increase the fuel pressure
Diagram courtesy of Tmoss & Stang&2birds
See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/ Everyone should bookmark this site.
Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif
Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif
Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif
Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg
HVAC vacuum diagram
http://www.veryuseful.com/mustang/tech/engine/images/Mustang_AC_heat_vacuum_controls.gif
TFI module differences & pinout
http://www.veryuseful.com/mustang/tech/engine/images/TFI_5.0_comparison.gif
Fuse box layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif
Last edited:
I appreciate all of the replies and thanks for all of the information! To address some of the above questions yes I changed the fuel filter and sock when draining and replacing the fuel and yes I changed the oil as well. I'm not sure what fuel pump is in the vehicle currently but I'll text the buddy I bought it from and ask! Just out of curiousity what is wrong with the intake that makes it a fire hazard? Oh and the vehicle does have a larger maf sensor housing and an aftermarket maf sensor. I do plan on having it dyno tuned I just didn't want to pay for a tune if I have to change the entire layout of the engine
as someone who takes carb cars and converts them to EFI (along with building and tuning standalone ECU systems) I don't understand why you would do that. You would do well to ignore anyone who gives you advice on facebook. if it is using oil now it will use just as much oil with a carb on it.
lets start over, [assuming you have done the appropriate testing and things checked out ok.] when you were setting the rocker arms what was your method?? with pedestal mount you will need to be sure the pushrods are in fact long enough to get the recommended preload. with stud mount you want to set the rockers to preload, my method is to set them just until i can turn the pushrod by hand with resistance.
the Intake manifold uses a set of BBK fuel rails, the fittings they supply along with the pushlok style hose is prone to leaking when not installed correctly. this is a known issue with the manifold, a simple fix will be to go through the system and check the connections and replace with an style fittings and hose.
If the meter and injectors are on the car now we can help further with closeup pics of the items, we need part numbers to get the relevant specs on them.
Lastly does the car run now? if so does it run well? besides the valvetrain noise what other issue does it have (assuming it is valve train).
lets start over, [assuming you have done the appropriate testing and things checked out ok.] when you were setting the rocker arms what was your method?? with pedestal mount you will need to be sure the pushrods are in fact long enough to get the recommended preload. with stud mount you want to set the rockers to preload, my method is to set them just until i can turn the pushrod by hand with resistance.
the Intake manifold uses a set of BBK fuel rails, the fittings they supply along with the pushlok style hose is prone to leaking when not installed correctly. this is a known issue with the manifold, a simple fix will be to go through the system and check the connections and replace with an style fittings and hose.
If the meter and injectors are on the car now we can help further with closeup pics of the items, we need part numbers to get the relevant specs on them.
Lastly does the car run now? if so does it run well? besides the valvetrain noise what other issue does it have (assuming it is valve train).
Take that intake off to make sure there are no issues with gasket fitment, install a different intake and put the pcv back in.
Make a list of things we have suggested and go over them one by one,
Make a list of things we have suggested and go over them one by one,
