engines out

[alloydave]

well i finally got pissed off with the falcon not running properly . Ever since
i had the problem with the dizzy drive i had a feeling i wasnt getting the full performance from my engine ,the bits i have in it i just thought it should go better.Anyway i ripped it the head off for a start ,as i suspected
its all choked up with carbon ,not bad for 150km driving :x .The bores look good with all crosshatching still evident ,the tops of the pistons were
easily cleaned with a rag and some petrol .I checked all the lifters and they still look like they came out of the box .This brings me to the camshaft that looks goods from what i can see ,but that comes out in the weekend .Checking the wear on the cam drive ,on rocking the engine you
can get about 5-10 degrees of movement of the crank without seeing the rotor arm moving .So my conclusion is that the cam gear has worn that much the timing is wayout or maybee the timing chain has stretched hence making the valve timing late ........=rich black mess .What do you fine gentlemen think from this basic diagnostic dillema.
i also had a problem of it wanting to pink alot ,it was running 98 octane ,but i think it had a dose of 96 at some stage.It runs about 10.5:1
comp ratio ,do you think that would have contributed to the BLACK MESS!!

cheers dave

 

[addo]

Interesting and not-so-good news, mate. Guess you've got more time now than in a few months, though. Carbon - what about excess fuel from the 4-barrel that wouldn't run right? Once it's there, that could promote the knocking.

You were running the Rollmaster timing set, weren't you? I wonder if somehow a piece of dizzy gear got stuck in the teeth... Or if it stretched before it broke the gear?

Was this the same engine where you had all the other dizzy issues like blown coil? If so, then again, a feeble spark might have been leaving residue in the chambers.

What a bugger.

 

[alloydave]

GIDDAY ADDO, yep the engines had all of those factors the dodgy carb ,the dodgy dizzy which probably all had there part to play with the problems .But no stress i just got some free gaskets from my mate at
NZ GASKETS ,got some new rings on the way and got a crow cam on the way from aussie p/n #14892 .Anyone out there using this cam ,how does it go ?

cheers dave

 

[Anonymous]

Hi,

I am using the crow 14770 and find it great, i would just make sure you have enouph valve to piston clearance if you have shaved a bit off the head. I had to use a decompression plate to give a little more clearance and i think the 892 has about the same valve lift.

Cheers

Simon

 

[addo]

Same nominal lift of 510 thou for both. I have been considering the 770 grind as a starting point for the precrossflows. As for the difference between your two cams, , I think the 892 trades a little power for greater tractability over the RPM bandwidth.

Cheers, Adam.

 

[alloydave]

just a quick update on my progress.The engine in bits now and i have found that the dud dissy drive has worn the cam a fair bit ,theres about 60-70thou play in the gear vs the cam. i have taken all my pistons out and cleaned them all ,they look brand new .I checked the bearings and the crank and there in perfect condition ,but i will change them anyway.Got the the new cam on the way and the new rings should be here soon .Im getting a reconditioner mate to check the bore ,it doesnt look to be glazed at all but i will get it check just in case.
Im also going to cc my chambers ,i dont know how much the guy took of the head when i had the porting done .The pistons im running have a comp ratio of 9.8 :1 @80cc ive got no idea on the cylinder head cc but i know the pistons have a 8cc bowl and sit flush with the top of the block ,so i think my comp ratio could be way up from where i was thinking.

cheers dave

 

[Anonymous]

Ive got a latter model EFI dizzy in my 250 2V and it has a bit of free play in it. My mate, GS pack has same engine with elect dizzy, he told me recently that his has enough play to make it impossible to keep in tune.
What compression are you running 9:8 that sounds high (maybe too close to bordeline I think, maybe right on it?). Ive got 9.0 comp 15cc dish I think and a smaller standard 2V chamber. Are you getting the same cam, its a good idea to get a new dizzy gear drive with it (Crow have them)

 

[addo]

Tim, the guys I have been dealing with for dizzies reckon there's 40 thou difference in the shaft sizes - that explains the free play! I just had one modded: 530 thou shaft and new bush onto XE dizzy. You then need a Crow DG-2A (I think). It will now fit snug into XT-XB.

Cost was $150 to do this but I supplied clean dismantled parts and they recurved it (mechanically), too. Just finished the final assembly an hour ago.

Adam.

 

[Anonymous]

Thanks for that info, invaluable. The two dizzys looked exactly the same from the gear drive up to the base from memory I remmember checking and re-checking it numerous times. Mine runs like a clock ticking with the elct dizzy no fluctuation in revs at all.
What do I need to do?

 

[addo]

40 thou - I felt so stupid! Someone who can eyeball a 5 thou wind on a head missed that? Pulled out the calipers and there, he was right, I was wrong. Check your old mechanical (points) shaft size below the gear. If it's 490 thou, you're set - if it's bigger, you're where I was...

 

[alloydave]

ITS BACK!! finally got round to getting my engine in aand out of the reconditioners .They have honed the bore (just to clean it up ) and fitted my new rings and bearings and installed and dailed in my new cam (crow 14892) .The guys replaced the cam thrust plate as this was quite worn ,i thought they checked this when i first had my engine built but i guess $hit happens.They have also given the dissy a bit more up and down play as it was apparently to tight and may have put to much thrust on the gear or something like that.It looks as if the 465 holley in its sad state was over fueling ,as my reconditioner said my old rings were very sharp on the bottom edge a classic sign of bore washing.A new timing chain was fitted just in case the old one had stretched and im fitting a standard oil pump vs the high volume as according to crow cams this will
make the problem of premature gear wear less prone to happening .
so its been and up and down year so far ,but i thinks its on the upside now.
:x :x
cheers and a merry xmas
dave

 

[xctasy]

Good news Dave!

I'm pleased you've got it sussed.

From an old post http://fordsix.com/forum/viewtopic.php?t=7015, here are the stats on your carb.

No|Number|CFM|Type-|Pri B"---|Pri V"-|VentASQ"|Signal%|Sec B"---|Sec V"--|Total V AREA|Air SPD--|PriBHP-|TotalBHP-|

14|#4160-|465|2-bbl-|1.5000--|1.0938--|1.8790-|37.1-|1.500-|1.0938--|3.759-|~297ft/sec|146|291|

David Vizard says that you take he venturi sizes in inches (1.0938"), divide them by 20, and that gives your jet sizes. In this case, 55 thou is ideal.

From some notes I posted, this is 239 cc/min or 55 thou nominal, a 56 call size jet. http://fordsix.com/forum/viewtopic.php?t=8106&start=0&postdays=0&postorder=asc&highlight=

With four of these jets (956 cc/min total, you'd get 159 to 191 hp, with 175hp the likely figure).

I did see and list your jet sizes somewhere, but my thinking is there's a 225 hp engine hiding in there, so four 62 call size jets should be best. There are common metering plates around for the secondaries which have jets about this size.

The 465 cfm carb is a stout bit of gear, and can run up to 290 hp fairly easily.

You you really think it was over jetted, or was it just a dirty needle and seat or too savage idle mixture?

 

[alloydave]

Hey X , i think the carb was slightly over jetted ,i cant remember exactly what jets a had in to start with.What we did see when it was idling was fuel dribbling off the venture boosters and pooling on the butterflies.The float level adjusting didnt effect this dribbling, after closer inspection i noted the boosters were loose in the carb so i had to take it apart and peen them so the didnt move. also had a problem with the vac sec pot ,when i buttoned of the gas the motor would rock back and smack the vac pot on the shock tower (ouch!!).So i pulled it off a stuck on the 500 2 barrel which has 69 jets and a 7.5hg p/v .I did a spark check just before i got pissed off and stripped the engine ,the coil lead sitting on the gaurd had a good 1" spark (my poor paint) but at the plug it was piss weak orange .So ive got some new leads/cap/rotor to try and ditch those custom 11mm leads .Heres a question should my coil be bolted to the block or can it be on the inner gaurd ?,i have a earth strap on the engine and another th the chassis.
cheers dave
merry xmas