My 427 SOHC Build..... Finally the time has come!

[jayb]

I would be rather circumspect about the cam card.  For quite some time Comp Cams had inaccurate cam cards for their SOHC cams.  Racedyne may be the same way.  This is probably a little disheartening, because as engine builders we rely on information from the manufacturers to be correct.  But believe me, I've been through this more than once and the SOHC is a whole different animal; you can't necessarily rely on anything printed about it.  I would really suggest that you measure the cams.  The guy at Racedyne is correct, the stock cams do have long ramps.  But as soon as the lash is taken up, you are off the ramp and the valve is starting to open.  That seat to seat number is definitely going to be bigger than 254 if those cams are close to the stock ones...

[cobracammer]

I found this with a little digging on the internet.  Does this look more like a 427 SOHC factory cam?

                                      Intake               Exhaust
Opening at .100 valve        22 BTC               58 BBC

Closing at .100 valve         40 ABC                4 ATC

Duration                           328                    328

Overlap                                       112

Valve lift-zero lash                                      .565

lash cold                           .015                    .025

Rocker ratio: Minimum 1.227 Maximum 1.307

[jayb]

Yes, those look like the factory cam specs.

[cobracammer]

Wow. they seem way off.  I will check when I get home.  I would hate to have to buy new cams.... these were $1,095.00 and they were the first part I purchased back in 2010  :0(

[cobracammer]

So I guess its not that far off..... question is

33ccs is more like it for the piston dome volume; that is a believable number.  Next, I would suggest you call Racedyne and ask about the seat to seat duration number, because that is certainly not correct either.  You could measure the seat to seat duration as well, if you have some V-blocks and a dial indicator with a point on the end.  Also, despite what Pond's website says, I'd call Robert as well and ask about the deck height, or better yet measure it.  I don't think I'd deck the block if I were you; you will end up cutting off the tops of the sleeves that way, then if you ever have to replace one of the sleeves the new one will be higher than the others, and you'll have to deck the block again. 

I'm guessing that your combination will work, but your original question was will it run on pump gas, and until you've got the compression ratio and cam nailed down, it will be hard to say for sure...

OK...  The cam card says:

Installed Timing:  0
Intake Lift:  432                Exhaust Lift:  432
Intake Duration:  258       Exhaust Duration:  258
Intake Opens:  21 BTDC    Exhaust Opens: 57 BBDC
Intake Close:  57 ABDC    Exhaust Closes:  21 ATDC

LCA: 108
Overlap: 42

Now just to get some additional info, I emailed the techs at CompCams.  They wrote back with this:

"The stock specs were around 255 duration at .050 with ..565 lift on a 112 LSA"

So knowing this Jay, will my setup work?

[jayb]

It looks like the specs on the cam card for duration are actually for duration at .050".  So, if that is the case those cams should be fine - Jay

[cobracammer]

OK, so given the deck height at 10.170 (Still awaiting word from Pond on that), and using a compression ratio calculator, I get :  11.26: 1

I have attached a screen shot of the calculation.  Is this correct?  and if so (Because it sounds freaking awesome) will that run on 92 octane?  LOL

[jayb]

I get the same numbers for static compression.  How well the engine will run on pump fuel is better predicted by the dynamic compression ratio.  In order to figure that, you need the real seat to seat timing for the cam.  And I'm afraid I don't know what that is for the factory SOHC cams.  My guess, though, is that it is around 300 degrees, which would leave you with a DCR of around 8:1.  That is plenty low to run pump premium; in fact, you could probably use even more compression and still run pump fuel easily, if my guess on the seat to seat duration is correct.

I hate to be repetitive, but you really need to measure those cams to know for sure.  Do you have a dial indicator?

[cobracammer]

Hey Jay,

I do not have a dial indicator yet.  I am placing a comprehensive order at Jegs to get all the lube, sealant, tools, etc. for the build.  I have a dial indicator as well as a magnetic base for it as well.  I will let you know when it comes in.

Thanks again!

[cobracammer]

OK!!!  I found this while doing a little research.  This seems to be the blueprinting specifications for a 427 SOHC (I just posted the specific pages, but I have the whole manual).  Are these specs accurate for this build?  This lists all the bearing and journal clearances...  This would make life a little easier during assembly...  Wasn't sure because im sure Aluminum acts completely different than Iron when heated?

[cobracammer]

Ok. Block and crank are at the Machine Shop!  Was a little bit scary dropping off the "Babies" with someone I don't really know  LOL
I got a chance to speak with the owner of the race engine shop that is doing the machine work.  He stated that although Aluminum race blocks are really expensive, they are not machined really all that well.  He is going to Bore the block out to the required 4.250" (I forgot to bring the head gaskets for the Boring process), He will balance the crankshaft, line hone the block and install the cam journal bearings.  It will be 2 weeks before I get them back, but its perfect as I just ordered all needed tools, lubes and etc. from Jegs in order to make this build seamless.

Pictures on the Engine stand ready for assembly next!

BTW, can anyone take a look at my previous entry (picture) and tell me if all of those specifications will work for blueprinting during assembly?  I got them from the old 60's 427 SOHC service and Maintenance manual?

[cobracammer]

OK Mr. Pond from Robert Pond Motorsports got back to me in regards to the Main Journal Bearing clearance.  He states that on his aluminum SOHC blocks, he recommends a clearance of between 0.0025 and 0.003.  The original specs for the SOHC were between 0.002 to 0.003, so I don't see much difference there due to the block being aluminum instead of Iron. 

[cobracammer]

Progress!  Got my shipment from Modern Driveline Yesterday.  Those guys are awesome.  Got my T56 XL with Ford FE Bellhousing and a custom bellhousing spacer made by Tremec so that it will all mount seamlessly on a Ford FE Engine (CAMMER!)..Twin disc racing clutch, everything down to the knob supplied by Modern Driveline.  Should slip right into the existing shifter boot on the Saleen. 
Bringing the Head gaskets to the Machine shop tomorrow so Tim at Mustang Racing Performance can start my machine work on the block and crank.... If all works out as it's supposed to, I will have it all back Next Saturday.

Also got my shipment from Jegs with indicators, gauges, lubes, degree wheels, everything!  Now that I have a dial indicator, I should be able to accurately measure the cam lobes.  Jay, when you have a second, can you tell me how I can go about double checking those with the dial indicator?

More to come.... stay tuned!

[cobracammer]

Stopped by the machine shop today..... little hiccup.  They do not have the torque plate measuring 4.250" for the FE engine and had to order it.  Says it is going to be a few more weeks.... :0(  Anyway, said he would go ahead and balance the crank while he is waiting....

And in another small world, I was explaining to this gentleman what the block was going to be used for... SOHC, and how I got the heads cnc'd in Arkansas by Keith Craft.  At this point he stops me to tell me that he is friends and partners with Keith Crafts old partner???  How small is this world?  Said the guys name was Bill Koontz (Prob. spelling it wrong).... but just goes to show you how small the FE world really is....

Purchased Gray VHT paint for the rear end housing and Black VHT for the 3rd member.... will be painting it and putting up pictures this weekend.

[jayb]

He probably meant Jim Kuntz.  Kuntz and Craft partnered for a while, and then split up and now run different shops.