The V8 Owners Forum -

Tony, now you have eliminated the stem seals and will be moving onto the rings, but on what evidence? I looked back over the last three pages, but cant find anything posted regarding leak down test results.

Sorry to harp back, but with the massive suction developed on overrun by your big engine it would be a shame to overlook the distinct possibility of that unregulated suction really is the cause.

# On the original 3.5 flappers, the overun valve took care of this anyway. It was a clever device in several ways.

# On later 3.5's with cutoff valve/relay the suction was unregulated but the problem was not experienced either.

# A 4.6 has 30% volume increase over the 3.5's and tho' I'm not certain about the science I'd wager that the suction is a squared function of that increase. If true, that is a massive 70%.

Again, as explained

ramon alban wrote: Tony, I thought I'd explained that massive overrun vacuum (and maybe even lots more on your arrangement) sucks oil upward if there is (scraper) ring/bore damage, so the oil passing though the hot engine/exhaust is only partially burned giving a typical blue smoke, indicative of little or no actual (black) oil burning.

# Re-thinking my above statement its entirely possible to visualise with ZERO ring/bore damage on a brand new home built engine with little or no carbon sealing in the ring grooves, the suction I am banging-on about (perhaps as much as 70% over normal) is sufficient suck oil up thro thro a gnats arze let alone a perfectly good but brand new engine.

# So what to do? Got to be worthwhile trying to measure that vacuum on overrun and seeing just what you are dealing with. God know how tho'?

# Alternatively fitting a vacuum release valve somewhere on the plenum side or one of its pipes, plumbed back into the air rail - if there is one, or the input tunnel.

# By artificially limiting the vacuum on overrun you could save a whole bunch of fruitless rebuilding.

I bet you're really pleased I dropped by to cheer you up?

i know what your saying above mate,
BUT

our concern is why is it only two plugs fouling with oil~?
thus why no matter what happens we are removing the engine to inspect these two cylinders as its strange its only on two cylinders and not all 8,

also regarding previous posts regarding my sump and windage tray,
have had a few mails from guys running 4.6 and 5.0 v8's using sd1 sump which has been modded to clear the crank throw and also the sd1 windage tray like me,
and they have had no oil probs like im seeing.

thev8kid wrote:our concern is why is it only two plugs fouling with oil?

OK, sorry, I missed that in my review of the notes - 10 pages now - phew!

Good luck with the rebuild.

Ramon

right now have the parts, (cheers Pel for collecting them from RS for me mate),
Met Pel at a service station in Bicester, Oxon today to exchange a package for some cash,
I recon the garage attendant thought dodgy dealings were going on



just to make sure every thing is right this time,
what should the ring gaps be? incase i got this wrong, which if i had surely all 8 would be playing up
is it just the top or top and second that needs doing?

and the plan is to run a charger at a later date so will the gaps need to be different???

hi Tony
It should be written on that bit of paper in with the rings but I am running 18 thou first and second rings and 22 thou on the oil control pack, .0045 X cylinder bore, so on your 3.7"s about 16.5 thou is correct
I would run 22 to 25 on the oil control pack, I wouldn't change much from that for running boost, maybe run 18 thou on the top ring but keep the second at 16.5.
Bset regards
Mike

cheers mike,
all written down and noted mate

Tony, have my ringgaps just as oem specifiet.
Meaning I did not have to file the rings RS suplied me. (where within oem specs after measuring).
Only have some blowby after 5000rpm which seems to be normal for a blown engine.(PCV system fully functional with 2ltr catchcan within the PCV lines).

I suggest to replace all rings and hone all cilinders to be shure if you have a set of 8 ringsets now.
Please give your engine a proper break-in this time. Want to race you at the comming up Classic Ford show mate

JP. wrote:Tony, have my ringgaps just as oem specifiet.
Meaning I did not have to file the rings RS suplied me. (where within oem specs after measuring).
Only have some blowby after 5000rpm which seems to be normal for a blown engine.(PCV system fully functional with 2ltr catchcan within the PCV lines).

I suggest to replace all rings and hone all cilinders to be shure if you have a set of 8 ringsets now.
Please give your engine a proper break-in this time. Want to race you at the comming up Classic Ford show mate

your on mate,
i will be running no gas or charger for that show so its as is,
unless me and perry can do a bit of testing before and run a hit as much as we can before needing any retard,

well this time tomorrow,
the engine should be out, stripped and possibly half way back together,
will let you all know if i find something on cylinders 4 and 8 when heads are removed, and when pistons are removed,

today is a no go,
the car refusses to start,
dumps loads of fuel in and thats it coughs a few times then wont do anything else., killed two sets plugs trying to start it, its now left in the garage till i can find out why she wont start,
it drove fine last weekend,

just been looking over the datalog,
and it showing bugger all kpa while cranking, and when its just sat idle not cranking,
its showing 14-15kpa then 14.8kpa while cranking,
map sensor died? or more ecu board probs???

its confirmed,
the map sensor has died,
its now removed from the board, and a new one order should be here by the weekend, so fingers crossed it runs again, and this weekend the engine work can comence again

HI every one.
we have found the problem,
and im tempted to say fuckit alnd sell the car,
and not bother with the v8's anymore,
after putting 3k into the car last year as well as the new engine,
i will be off the road again this year due to either a rod or pin failure and this is whats causing the oil burning issue as its chewed the liner on cylinders 4 and 8 not the sump or baffle or breathers like others sugested,
im sat here now wondering weather to laugh or cry, im gutted





the worrying thing is, there were no knocks or bangs when running, ran smooth as a nut and reved up crisp still,

Ouch- Tony you have my condolences, what pins and pistons have you got in there?

Cheers TC,
4.0 pistons,
4.6 rods,
stock fittment pins