Airbur's 427W Build Thread

[nvrstuk]

Dang, it must be nice to finally be able to put the timing chain assbly on!! What compression ratio are you hunting for? Looks like 26cc or close to it, dish pistons. I'll pm you my 4R70W shifter pics, not sure I can figure out how to post pics on the forum!

[airbur]

10.63:1 on the compression. The pistons are very close to the deck height though so may need a larger head gasket.

They are 22cc dish pistons.

[nvrstuk]

Stock heads
C90E-D 1969-1974 351W, 60.4cc chambers, 1.84/1.54 valves
C9OE-B 1969-1974 351W, 60.4cc chambers, 1.84/1.54 valves


10.59:1 is what I came up with guessing on your deck clearance

4.030" bore x 4.170"
.040" compr head gasket
4.050" gasket vol.
22cc dish
stock C90E head

[airbur]

Haven't had a chance to run the #s but I am going with 185/58 AFRs, 2.02/1.6.

[airbur]

Here's what I come up with....

[Booger]

Isn't the head gasket thickness and head gasket bore switched in that screen shot?

[airbur]

Isn't the head gasket thickness and head gasket bore switched in that screen shot?

Hmm...you may be right....switching them comes out to 10.49:1...but I know that isn't correct....need to do some more figuring. I haven't chosen the gasket yet.

[ZOSO]

A premium only motor huh?

[airbur]

yep....that was expected.

[nvrstuk]

Do you have the 58 cc heads already? Comp or emissions legal? The 185 comp heads flow within 6 cfm or so of the 205's and for our application (according to AFR techs) they will still have the same port velocity at low-mid range rpm for max torque. I'm planning on going with the #1383's. You can mill .006" for every cc on that head to dial in your compression ratio.

lot's of options...they just all take away from and

back to the shop...

[airbur]

Do you have the 58 cc heads already? Comp or emissions legal? The 185 comp heads flow within 6 cfm or so of the 205's and for our application (according to AFR techs) they will still have the same port velocity at low-mid range rpm for max torque. I'm planning on going with the #1383's. You can mill .006" for every cc on that head to dial in your compression ratio.

lot's of options...they just all take away from and

back to the shop...

Nope, haven't bought them yet. No emissions necessary so will be comp version. That's good info though. When I did my calculations with the 205s....something wasn't right.

[airbur]

So I did some figuring, and with my current 58cc heads here's the new calculation. I also did it with those larger heads and the compression dropped to 9.26....how would that affect power?

http://www.gtsparkplugs.com/CompRatioCalc.html



I ordered the timing cover and water pump today.

[airbur]

20% off the order plus a $50 gift card:)

http://shop.advanceautoparts.com/webapp ... nt=general



http://shop.advanceautoparts.com/webapp ... nt=general

[nvrstuk]

Dang purdy looking...Exploder front dress?

I did some head milling figures and if you cut the 72cc heads to 64 then you'd drop to 9.95:1 compr. I haven't talked to the AFR tech guys about milling that much off, but taking them to 66cc wasn't an issue. They'll mill them at their factory for $100

Not sure I'd bump up the compressed gasket thickness much. It will really affect your quench if you get too high. That will also affect your cyl burn and timing, etc.
You don't lose much hp by reducing your CR. Performance Trends Engine Analyzer thinks when raising the compression ratio from 9 to 10, it thinks that HP will increase by appr 3.8% and torque improve by 2%. If I was going for ET's, that'd be one thing.

Just my .02, but try to get the compr ratio down to a number you can run on pump gas anyway. With all the power you'll have under the hood, you aren't going to notice 18HP difference! : )

[airbur]

Thanks for the info. I thought I had this figured out....but I don't. Found a great article on compression and pump gas....

http://www.popularhotrodding.com/engine ... ewall.html

Pretty technical but just how I like it.

When you say that AFR will mill the heads for $100 at their factory....does that mean you would send them in to AFR? Or would you buy them direct? Their prices are horrendous compared to the dealers (summit etc).

Just found a bit more info...from the AFR catalog on the #1383s.....(http://www.airflowresearch.com/27-31.pdf)

Angle Mill (10cc Maximum Optional Mill)-----------------------------------.008” per cc
Flat Mill (4cc Maximum Optional Mill)--------------------------------------.006” per cc

So that tells me we could get-er down to 62cc with an angle mill. At 63cc, that puts me at 10.03:1....I still need to recheck piston to deck height.

[airbur]

Ok, so here's my latest calculations. I measured the piston to deck height at lunch and came up with an average of .009...talk about "zero decking" :). With that # and including milling the heads down to 64cc.....that puts me right at 10.06:1 compression.

[Rox Crusher]

now we're talking

HP and reliability !

[nvrstuk]

You'll like these numbers a lot better! Every time you fill up!

Guys all the time talk about having to run max compression or your motor will be a dog...yeah, "a dog motor" at 9.8:1 compression only cranks out 500+ HP and 500+ft lbs of torque... : ) let me walk that dog!!! All on pump gas....nice...

[airbur]

I'm going to talk with Scott at MPG Head Service and see if he can do the AFR milling...he's local and is the one that build my cam.

http://www.mpgheads.com

Last night I went through all my research on the bolts needed for the Explorer serpentine, water pump, and timing cover. I went to Ace and they didn't have any of the odd lengths so I did up an order with Fastenal. They have everything except the one 5/16-18x3/16 bolt so I'm going to try a 1/4.

[ZOSO]

You'll like these numbers a lot better! Every time you fill up!

Guys all the time talk about having to run max compression or your motor will be a dog...yeah, "a dog motor" at 9.8:1 compression only cranks out 500+ HP and 500+ft lbs of torque... : ) let me walk that dog!!! All on pump gas....nice...

Max compression is just to make up for the wrong setup. Id rather keep compression below 9.5:1. Pump gas friendly. Its all in head cam intake setup. And that much power in a Bronco would be fun. But you start to break parts. My 460 in my 79 is around 330hp. More than enough for a wheeling rig.

[airbur]

So here is the new timing cover I got from AdvanceAuto...it's a Dorman model. Crap.....guess it's off to the junkyard again.

[airbur]

The new timing cover (ATP brand) and water pump arrived today. Both in perfect condition. Waiting on the bolts for the serpentine and also the windage tray and bolts.

http://www.amazon.com/ATP-103039-Timing ... 426&sr=8-1

[nvrstuk]

...still waiting...



: )

[Booger]

............ My 460 in my 79 is around 330hp. More than enough for a wheeling rig.

Yea but how much torque? Enough to break parts if your not careful!!

[ZOSO]

............ My 460 in my 79 is around 330hp. More than enough for a wheeling rig.

Yea but how much torque? Enough to break parts if your not careful!!

Oh about 600ft-lbs

Plus on that note of compression. If this is a wheelin rig and you get out there in a little town and running on fumes chances are you wont find premium. I ran into this with my 79 when I was having timing problems. It would always ping going down the highway. I had to run premium until I found the problem. Just something to think about also. In my builds I have been taught to keep it simple with a lot of simple/stock parts for reliability. When your out in the middle of nowhere and something goes wrong stock parts are easier to find.

[Booger]

You learn good Grasshopper.

[airbur]

............ My 460 in my 79 is around 330hp. More than enough for a wheeling rig.

Yea but how much torque? Enough to break parts if your not careful!!

Oh about 600ft-lbs

Plus on that note of compression. If this is a wheelin rig and you get out there in a little town and running on fumes chances are you wont find premium. I ran into this with my 79 when I was having timing problems. It would always ping going down the highway. I had to run premium until I found the problem. Just something to think about also. In my builds I have been taught to keep it simple with a lot of simple/stock parts for reliability. When your out in the middle of nowhere and something goes wrong stock parts are easier to find.

Some wheeling ....mostly street. Plan to carry octane booster on trail runs:)

[nvrstuk]

A full compression point drop- let's say 10:1 to 9:1 is appr 3% or so drop. At 500hp/500ftlbs torque (goal for most streetable 427 SBF stroker builders) you're not losing much for OUR uses... different story for ET's on the strip, you can't give up any of either.

An axle spline, axle eater is what he's building. I don't know if Eric's locked solid front and rear but if he is, parts will twist... :)

I'm up to 35 spline alloys with pro-nodular Strange 9" now. I've twisted everything else off...

save some $$ for upgrades :)

[airbur]

The axles are stock:) I plan to get this thing installed and then see what blows up (axle-wise). Then upgrade as necessary:)

[airbur]

Got some parts in today. Scoop, timing pointer, oil pump bolts.