Factory Five Racing Forum banner
1 - 14 of 14 Posts

·
Registered
Joined
·
848 Posts
Discussion Starter · #1 ·
Sorta confused and in need of some help with breathers and/or PCV on the engine for my Mk4.

Engine is installed but not yet fired ...

5 Liter engine sourced from an '89 Mustang GT is a recently complete rebuild ... bored 0.030 over (now 306 cu), including the following:
- Edlebrock Performer RPM aluminum heads,
- Comp Cam 35-510-8 (Hydraulic Roller Tappet, Advertised Duration 258/266, Lift .533/.544)
- MSD "Atomic" EFI (tbi-style system)
- MSD "Ready-to-Run" distributor and wires

Valve covers came from a Forum member - and i don't recall if there's any internal baffling in the covers or not :(
PS valve cover has an approx. 1 1/4 inch hole (with "ears") and the DS has an approx. 1 1/4 inch tube (w/o the grommet and 1 inch with the grommet.

Couple of pictures are attached. (Note: both sides are normally taped over to keep dust, debris and etc out of the valve cover, but were uncovered for pictures)

All that being said ... do I need suitable (and "cosmetically pleasing") breathers on each valve cover
OR
do I need a PCV valve with lines running to either the air cleaner housing or the base of the efi unit (i.e. base of the "carb") on one side and a simple breather or ?? on the other. "Atomic" instructions from MSD do not mention breathers nor PCV.

Help with what's needed ... and well as specific parts suggestions :) ... will be greatly appreciated.

Many thanks

Lynn
 

Attachments

·
Charter Member
Joined
·
6,164 Posts
the normal way is a pcv plumbed to the base of the carb/efi unit and a breather on the other side.
You can put a breather on both sides but this can cause oil residue in the engine compartment. It might not happen during street driving. I have to plumb both of my breathers into a vented catch can. I get a lot of oil residue in the can after only one weekend at the track.
 

·
Registered
Joined
·
1,182 Posts
Free bump for the topic.

My stock '93 motor had an oil filler cap in one valve cover plumbed to the upper intake, nothing in the other valve cover, and the PCV comes from the rear of the lower intake manifold.

I've been wondering if I needed better breathing, too so I'm watching with interest.
 

·
Not a waxer
Joined
·
12,092 Posts
Here are some visuals for you Lynn. As Trevor said the PCV goes in one side and is plumbed to the base of the carb or throttle body. You can see it here forward of the Cobra logo with the hose going towards the front then looping back to the carb base:



The breather can be an open element type but I prefer a sealed unit with a port so that a hose can be routed to the filtered side of the air cleaner base. This way the engine is ingesting "clean" air. You can see the hose running from the breather to air cleaner here (nevermind the lables; I put those on there for someone else in another topic):



It doesn't matter which side of the engine has the PCV or breather.

VERY IMPORTANT
The valve cover has to be baffled below the PCV port. Ford Racing M-6582-A and M-6582-F302 covers are baffled; M-6000-C302 is not. You should be able to easily see the sheet metal baffle through the hole. If not baffled you'll see all the way through to the head. If they aren't baffled oil mist and splash off of the rockers will be flung directly at the PCV and drawn through which will lead to excessive oil consumption and smoke.

DARKPT,
That is the OEM setup for an EFI 5.0. In addition to the PCV running to the underside of the upper intake you should have filtered breather air coming through a hose that runs from a nipple on the top of the throttle body to the oil fill tube on the RH valve cover.

Cheers,
Jeff
 

·
Registered
Joined
·
1,182 Posts
Thanks, Jeff. I do have the line from the oil filler to the throttle body nipple.

I guess I was just wondering if the PCV from the valve cover is a superior setup to the stock Fox setup where the PCV plugs into the rear of the lower intake manifold.

Dan
 

·
Registered
Joined
·
219 Posts
The advice I got from Fortes, who built my 393 stroker, was this:

One of the valve covers should have a breather with branch port (1/2"?) off the side. Run the hose from the port to the base of the air cleaner (filtered air). The other valve cover needs a port connected directly to the base of the carb with a PCV inline. The idea is that under vacuum the PVC draws air from the crankcase but the air it draws comes through the other valve cover which is tied into the clean side of the airfilter.

I had the same "cobra" valve covers with the dog ear'd holes for the oil fill. Had trouble finding the proper breathers for it and bought some TrickFlow aluminum covers which had no holes. Drilled them for what I needed and used the grommets supplied with the PCV and breather to make a nice fit.

Can't say enough about the service I got from Mike an his engine builder Jesse. If you haven't been there the engine building shop is an old walkin cooler which is spotless. Their attention to detail is not like anything I have ever seen.

Car is at the body shop now but during a quick go kart I accidently/unexpectantly left a posi strip in my quiet neighborhood. I guess the folks around here should just understand it is a sign of whats to come.
 

·
Registered
Joined
·
848 Posts
Discussion Starter · #8 ·
Here are some visuals for you Lynn. As Trevor said the PCV goes in one side and is plumbed to the base of the carb or throttle body. You can see it here forward of the Cobra logo with the hose going towards the front then looping back to the carb base:



The breather can be an open element type but I prefer a sealed unit with a port so that a hose can be routed to the filtered side of the air cleaner base. This way the engine is ingesting "clean" air. You can see the hose running from the breather to air cleaner here (nevermind the lables; I put those on there for someone else in another topic):



It doesn't matter which side of the engine has the PCV or breather.

VERY IMPORTANT
The valve cover has to be baffled below the PCV port. Ford Racing M-6582-A and M-6582-F302 covers are baffled; M-6000-C302 is not. You should be able to easily see the sheet metal baffle through the hole. If not baffled you'll see all the way through to the head. If they aren't baffled oil mist and splash off of the rockers will be flung directly at the PCV and drawn through which will lead to excessive oil consumption and smoke.


Cheers,
Jeff
Visuals are very helpful. Thanks for posting them Jeff.

The "look" prersented by what you've pictured is pretty much what I'd like to achieve - along of course with the correct functionality.

We're away for the Holidays right now so I can't pop out to the shop a take a look, but from memory my PS valve cover is non-baffled (I could easily see the rocker arms thru the dog-eared hole) and my assumption (possibly in error) is that the DS (with the tube) would thus also be non-baffled.

If both covers are non-baffled, installing a pcv in either side would therefore lead to the excessive oil consumption/smoke that you mentioned - which is clearly not desireable.

Short of replacing the valve covers with baffled units, are there other options for PCV installation? I don't recall seeing a port/opening on the intake manifold that might support a PCV.

Thanks again

Lynn
 

·
Registered
Joined
·
848 Posts
Discussion Starter · #9 ·
No baffles in the valve covers ...

OK - so I pulled the valve covers and there's no inside baffles anymore ... operative word being "anymore".

The "threaded for screws" mounting pedestals and what appear to be pedestals with "locating" pins are there - but no baffles. Pic's I took of the inside of the VC's are in the camera which is out in the shop and I can post them later as an edit if they'd be helpful.

The VC's were purchased from a Forum member months ago and I frankly don't recall if the baffles were in the VC when I received them or not, and my engine guy says he didn't remove the baffles when he installed the VC's.

So - I'm heading to see my auto parts guy to see if he can help with 1) suitable grommets with baffles (e.g. Mr Gasket 6375) and breathers/PCV set up and so on to replicate what are showing in Jeff's pictures.

BUT - I thought I'd also check to see if anyone on the Forum has seen (or heard of) replacement baffles being available ...perhaps from a Ford dealer or ??

I'm NOT optimistic replacement baffles will be available - but figured it doesn't hurt to ask ... :balloon:

Thanks

Lynn
 

·
Not a waxer
Joined
·
12,092 Posts
Lynn,
I suspect that the same casting is used for both types of covers, hence the mounting bosses on the underside. It would be pretty simple to bend up your own baffles from sheet aluminum (this is what I did with my Trick Flow covers). No complex science to it; just clear the rockers and deflect mist/spray away from the PCV.

Good luck,
Jeff
 

·
Registered
Joined
·
848 Posts
Discussion Starter · #11 ·
After posting my last note, I did a bit of searching via Google, and was also going to look at the idea of making my own as you suggested using some thin aluminum sheet and screws etc. Seems like others have done it and sit doesn't seem to difficult.

If successful, I'll try to remember to post up some before and after pic's in case they're useful for others.

Thanks

Lynn
 

·
Registered
Joined
·
848 Posts
Discussion Starter · #12 ·
Jeff - sending you a PM

Thanks

Lynn
 

·
Registered
Joined
·
848 Posts
Discussion Starter · #13 ·
Still fretting over breathers and baffles ...

And possibly (probably?) making a mountain out of the proverbial molehill. :(

I took a stab at some DIY baffles to retrofit into the valve cover and I think the 1st one looks "reasonable".

Attached pictures show:
1st - inside of valve cover showing "pedestals" that appear to have formerly had a baffle atached.
2nd - my 1st try at a DIY baffle ... made of 0.008 tin (aluminum would likely have been better but it's all I could find on short notice)
3rd - "side view" of the installed baffle showing clearance to inside top of valve cover ... which approx. 5/16ths inch.
4th - installed rocker arms which I am "told" are stock ratio 1.6 rockers and that (hopefully) should NOT strike the baffle and go "tick-tick-tick" or similar/worse when the engine is running. Rule end is resting on the VC gasket mating surface of the head

Not sure how to properly measure head, valve cover and rockers to see if I got the clearance needed ... at least not without going to the 'put in a wad of clay and turn the engine over with a wrench' technique, which I'm hoping to avoid ... at least for now.

IF I decide to keep the DIY baffles, I'll be sure to use some lock-tite on the screws to keep them from falling out and into the engine where they could cause a lot of mischief. :evil:

Any thoughts on the baffles and esp. their probable clearance - one way or the other - will be greatly appreciated.

And before anyone asks, I REALLY like the cosmetics of my valve covers and would prefer NOT changing to a different style cover. Also, I cannot find them in a "tall" configuration. I am also concerned that adding "spacers" or doubled up gaskets to the valve covers for more clearance would also give the potential for oil leaks ... :(

As always - thanks for any constructive and helpful comments/guidance

Lynn
 

Attachments

1 - 14 of 14 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top