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

[Drew Pojedinec]

Wow I'm excited for you... this is an awesome thing.
I pine for the day I can afford just a 427 block

It'll be fun seeing the people scratching their heads trying to figure out what you've got going on under the hood.

[cobracammer]

OK, in order to prep a little (and start reducing a room full of boxes into completed assemblies, I put together the rear end.  Like I mentioned before, Currie offers a ford 9" drop in replacement with all stock 2005 Mustang GT mounts welded in place already.  This is a super nice piece.  31 spline axles, Large heavy duty bearings, and even has a backing plate so stock brakes and ABS sensor can be remounted.  Now as I was able to pull each piece out of room separately, once together.... Hernia!
Ford 3rd member Posi-unit was source from Speedway Motors.  After putting the 3rd member into the Currie housing, I torqued the lock nuts down at 20 ft Lbs in a crisscross pattern.  Then a final torque or 40 ft Lbs.  I actually ordered a speedway gasket that does not need RTV to make the seal, so this was actually not a messy job at all.
31 spline axles, which were part of the Currie package, slid right into place.  I am thinking this weekend of painting the housing an aluminum color, and the 3rd member in black... to keep with the stock theme.  I will take pictures this evening and post here.  Below is a picture my Saleen who will be getting an official name once this transplant takes place (any ideas on a name would be greatly appreciated):

[mike7570]

I hope you had your Wheaties before you try to pick up a fully assembled 9"
maybe  "Hernia" is appropriate name.

I found out recently how heavy they can be.

[cjshaker]

As far as the motor mounts, all FE's were the same with the exception of the Side Oiler.  Due to the oil galley on the drivers side, the forward most bottom bolt hole had to be moved 1/4 inch from the usual FE stock location.

Funny, I have never noticed the difference before, and I've installed a few sideoiler engines using stock 390/428 motor mounts. I'd check my blocks but they are both at the machine shop and my SOG block is bagged and boxed.

Those Saleens are really nice cars! As are the Roush cars. I test drove both, but settled on my GT because I got a steal on it with 3000 miles on the odometer and extended warranty. I added a Saleen front grille, front spoiler and a Roush rear spoiler and it helped high speed stability. They are a blast to drive! I'd make sure that grocery store is at least 10-15 miles away

[cobracammer]

OK so here are 2 pictures.  One is of the Currie rear end set up (Specifically for the 2005 Saleen) and the other is what a cammer engine looks like all in boxes....  I moved everything into the garage for final assembly.

Also of note, I went ahead and ordered a bolt kit from river city bolts (found them on ebay).  I got an assortment of all Grade 8 zinc yellow bolts in fine and course threads with grade 8 zinc yellow washers.... figured it would be perfect to have these all on hand rather than to run back and forth to the hardware store.  The guarantee that every bolt I will need for assembly only cost me about $110.00..... However, the mail lady hates me as every other day I am getting something that barely I can pick up...  I smell a Christmas tip coming  :0)

[cobracammer]

Also wanted to show what the Motor mounts look like as well as why they the drivers side needs to be modified.  See below for the pictures:

[cobracammer]

Question:  I want to make sure I get the correct compression ratio of 10.8:1 (Should be able to run well on 92 octane right?)
I am not quite sure how to compute, so here is what I have:

Pistons- C.D= 1.330, Pin: .990 x 2.930, CC's: 12.9cc, Compression: 10.8:1 (That's the compression ratio they have listed for these pistons)
Block Deck Height = 10.170
Rods = 6.700"
Stroke = 4.250"
Gasket thickness = I believe this is Cosmetics 4.400 bore with a thickness of 0.080"

So the Question is.... does this work out to to be 10.8:1?  If not, does the deck height need to be cut down?  Thinner gasket?  Wanted to figure this out before I drop the block off this Saturday...... Want to get it to as close to 10.8:1 as possible

Also, when having the block honed, do you have to let the machine shop know any final measurements?  Say the spec for a Cammer (Side Oiler) needs to have a specific main bearing clearance?  (I found somewhere online that blueprinting Spec for a FE block was in the range of (0.0025" to 0.0030").

[cobracammer]

Actually got this from Diamond Pistons, but I believe they seem to be using OEM deck height of 10.155 instead of Robert Ponds Deck height of 10.170.... but still don't see where they get 10.8:1

[Barry_R]

The aluminum block will want main clearances tighter than an iron block.  Keep the line hone on the small side of spec 'cuz the aluminum will grow with heat.  The block deck height should be determined for sure before making pistons - a set for the OEM 10.17 will be potential positive of the deck in a 10.155 Pond block.  "Measure once..."

[jayb]

10.17 is the stock FE deck height.  The Shelby block is 10.15" for deck height, and I thought that the Pond block was 10.15" also.  Like Barry says, you should measure to be sure, or call Pond to find out.  At least mock up the crank, a rod and a piston, and see where you are relative to the deck.

Using your numbers, deck of the piston is (4.25/2) + 6.700 + 1.33 = 10.155.  This means that your pistons will be at zero deck if the block deck is 10.155.

Chamber volume on the SOHC heads is 120cc.  I'm not sure if Cometic makes an SOHC head gasket with .080" thickness; I supposed it could be custom ordered, but most of them are .040" thick.  Again, you should measure the thickness. 

So, putting all that together, and assuming a 10.155 deck height, and a .040" thick head gasket, I get a compression ratio of 9.5:1.  Way, way too low for ANY SOHC engine.

Are you sure about the piston dome volume of 12.9cc?  That is really, really low for an SOHC piston.  Most of them come in around 35-38 cc.  Also, the cam specs you listed in the original post of 258/258 seat to seat can't possibly be correct.  That is way, way too low for duration.  That might be duration at .050", but not seat to seat.  If that is the case, do you have the seat to seat duration numbers?

I think you need to start measuring and checking things before you get too far along on this build.  A lot of the specifications you are putting out just don't add up, and you need to be sure about all that stuff before you assemble the engine.

[cobracammer]

Hi Jay,

Yea it was starting to worry me.  I am cutting and pasting these numbers directly off of the websites in which I purchased.

Robert Pond Block:
"Our SOHC Ford blocks are manufactured in both
 aluminum and cast iron. The specifics are the
 same as our wedge block, except they weigh 2 to 3
 pounds more due to no lifter provisions and have a
 deck height of 10.170 instead of 10.155. Also, there are
 no oil passages in the lifter valley area. However,
 there is an oil return hole in the back of the block
 that is unique to the SOHC head."

From Pistons (Diamond):

• Designed to fit OEM 427 S.O.H.C. Hemi engines
• Made from 2618 alloy for street/strip use
• Compression ratios calculated at 0.011” to 0.015” bore depth with 10.170” deck height
• Premium 8620 material wrist pins
• Gasket volume: 10.1cc’s
• Top ring down dimension: 0.480”
• Standard ring package: 1/16” x 1/16” x 3/16”
• Valve relief depth: 0.301” intake and 0.142” exhaust

Bore    Stroke       Rod          C.D.       Weight        PIN                   CC's        Compression Ratio (98cc) 
4.250    4.250     6.700      1.330      call          .990 x 2.930      12.9cc                  10.8 to 1


Racedyne (Cams spec card):

Cam Specs

Factory:

Lift;  Intake .433  Exhaust .430

Duration, seat to seat;  Intake258  Exhaust  258

Lobe Separation; 108



OK so (Please catch me if I am wrong) the Robert Pond block has a deck height of 10.170".  The Piston's I ordered from Diamond say that "Compression ratios calculated at 0.011” to 0.015” bore depth with 10.170” deck height"  (so it seems these pistons were made with the assumption that the deck height was 10.170"

And the cam specs are a cut and past from Racedynes website.  Please tell me what's wrong here.  From what I see, it would seem that the deck should NOT be milled down to 10.155 (Due to the pistons ordered?)
 

[cobracammer]

Got nervous and called Diamond Pistons....  They said they were unsure what the 12.9cc's are listed on their catalog, but the Piston Dome volume is 33cc's!

I worked it out with him on the phone and he said that if the Block is currently at 10.170 deck height, it works out to 10.6:1 compression ratio (given that Jay was correct that the head gasket thickness is 0.040"

If I deck the block 0.008, it comes in right at 10.8 : 1 compression ratio.... Does this sound correct?  :0)

[jayb]

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...

[cobracammer]

Hey Jay,

I contacted racedyne, and I received this:

"They are correct but the OEM grind has long ramps.  They run quite well on anything even close to stock."

If I remember correctly, this gentleman outsources these cams...  I have the actual cam card at home that I will pull out tonight and double check.  I had the heads completed by Keith Craft (Springs, retainers, valves, etc) and he asked for a copy of the cam card so he knew what we were working with.... and he didn't remark.

My guess is that the website is incorrect (as you said) and that the cam card prob. has better (more accurate information).

I also have word out to Robert Pond to make sure the deck height is 10.170"

I can't thank you and everyone enough for assisting me through this.  I am sure I am not the smartest guy making this my first engine assembly, but I'm DYING to get this engine running!   

Ill post again tonight when I have my cam card (Possible that I can just scan it and post the picture)

[cobracammer]

BTW, Thank you Barry.  I have been reading your book I purchased a few months ago. Very well put together.  Thanks again