|
Oil "Use" Ford 427/535 Crate
Have about 20k miles on the motor, very minor oil seeps only, all 8 plugs light tan with timing and mixture tell tales all in the right place, no smoke, but she goes though oil? Maybe a qt every couple fuel tanks which sure seems like ALOT of oil...
I had oil burners in college and besides having to feed them oil the plugs were always black and gooey...Aside from having to add oil there are NO other tell tale signs of the thing either leaking oil, bad guide seals or leaky rings? Made like 450 RWHP on the dyno... A bit mystified? Steve H SPF 1764 |
What kind of oil? Brand? Weight?
|
If the wrist pin is in the oil land, you're gonna burn oil. Built a couple big inch small block, burned like a quart every hundred miles. Never showed on the plugs. Last engine I built, 450 inch small block, I shortened the rod length 1/8 inch and moved the wrist pin down so it wasn't in the oil land. Never burned a drop of oil.
|
Oil
Quote:
|
So where does it go?
Quote:
Steve H SPF 1764 |
THe oil can only go two places. Out through the cylinders or out through a leak. Have you checked under the car for blow-by leaks? Do you have a light coating of oil and grime on the undercarraige anywhere?
|
Having the wrist pin intersecting the oil rings has absolutely nothing to do with oil consumption. If it did, then every 347 on the road would be using oil....as well as many other longer stroke engines in other engine families. It's a wives' tale and it's one that gets my goat every time I read it.
Oil consumption can come from several places and it doesn't have to be piston ring issues. Valve seals can wear out, valve guides can wear, PCV valves can go bad, intake manifold gaskets can leak. Some careful investigating will let you know where it's coming from. I'd start by pulling the carb off and seeing if there's oil laying in the plenum. If so, then it's probably something like a bad PCV valve. If you see oil on the intake valve stems, then it could be valve seals or guide wear. |
It's not in the combustion chambers...
Quote:
Need to do a real thorough chassis clean and crawl and chase this down. Thanks Steve H SPF 1764 |
Quote:
|
Quote:
Here's the thing....modern ignition systems are so efficient that they will burn the oil before it has a chance to get on the plugs or even show in the exhaust. Do you have access to a bore scope? If so, I'd snake it down the plenum and look at the valves. If the valves are clean and the plenum is clean, then the next obvious thing would be piston ring issues. I've seen issues over time with Mahle coated pistons and the rings sticking... |
Quote:
You would be shocked to see the amount of engines that not only leave my shop, but every other hipo engine builder's shop with the rings up in the wrist pin. A 347 Ford is one of the worst situations with compression height...they are sitting at a 1.090" height, with the oil rings right up in there. I know of one particular guy with over 100k miles on his 347....no oil consumption. The wrist pin intersection deal is just something that gets passed around the forums and it all stems back to a single faulty piston design from decades ago from Coast High Performance/Probe pistons. |
Could be intake manifold air leak. Squirt some carb cleaner along the sides with engine at idle. If idle changes, you are sucking air and oil in from the lifter gallery. Also check torque on intake manifold bolts, they tend to loosen. This happened to me on a 351W with FelPro black rubber intake gaskets and cork front/rear. I was using a quart of oil every 500 miles with no smoke and no obvious leaks. I reinstalled intake with Cometic gaskets and RTV front/rear and oil consumption returned to nil.
|
One more area an oil leak can occur, Wicking through the intake rocker studs. --Ask me how I know. Drove me nuts for a month. Once they were removed, dried and sealed my oily plugs and sheen in the intake runners was gone.
|
Thanks for all the ideas fellas, giving me some great things to check, Thanks
|
The intake rocker arm stud is a biggie. It will put oil in your intake ports pretty easily.
|
Brent what do you use for sealing. ARP thread sealant was terrible. I used ultra Grey which worked. Maybe I just didn’t clean the studs off good enough for the arp stuff to work but it took me twice to get them to seal
|
I use Permatex thread sealant paste.
|
intake rocker studs
Quote:
Steve H SPF1764 |
It depends on the head and how deep the rocker arm stud holes have been drilled/tapped. On a lot of heads, yes, the hole goes into the intake port.
|
Z304DA Heads
Quote:
|
| All times are GMT -7. The time now is 09:09 PM. |
Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: