I rolled the engine over this afternoon, and I can see the number D90E6110 AA cast into the backs of the pistons.

Can't find much on Google, other than what is linked below:

YEAR -- PART # -- Material/Type -- Weight (g)
79-84 -- D9OE-6110-AA -- Sand-Cast Aluminum/Four Valve-Relief Eyebrows -- 470

https://www.stangnet.com/mustang-for...erence.621796/

Just FYI really, nothing more.

 

He definitely does not want to deck that block. It's already thinner there than all other castings. The heads can be milled .040 without running into intake fitment issues, that'll get the chambers to around 60 ccs. Doing so will get it to just shy of 9 to 1

 

Are you saying just that year which I think is highly unlikely or just the mid eighties blocks or ? Or generally speaking about newer '85ish and up roller blocks? I get that the 5.0 blocks ('85ish and up) were the lightest, thinnest blocks. But looking at his lifter valley this isn't a roller block.

 

The HO firing order is easier on the crank and bearings but that's not a hugh deal on anything but an all out racing motor. That 31-230-3 grind sacrifices some peak HP for a little more lowend torque... it's down to 275hp and peak TQ is about the same but there is about 20lb/ft more at 2000rpm.

 

The E0AE block is the thinnest lightest of all 302/5.0 blocks. (120 lbs)This is the block used from 1980 to 1984. The 85 Roller block was 2 lbs heavier, due to the added iron to raise the lifter bores to fit the roller lifters. The 86-up blocks got another 4 lbs added to the decks to stiffen them, apparently the 1980-85's had sealing issues. The pre 1980 blocks all weighed in at 136 lbs. This included the Mex blocks. I have personally weighed a 69, a 72, 2-78's and all weighed in at 136 lbs. One of the two 78's had the same thick main caps like the Mex and 289 Hi-po blocks. The casting suffix for that block was A3A. The other was 3A and had the regular small caps.
'

 

Oh wow, thanks for that info. I had never heard that about the early eighties blocks.

 

Gentlemen,

Thank you for all the replies and information. It is all very helpful.

Rem

 

Good to know Conanski, thanks. This thing will mostly just be for cruising around with once in a while, so the peak HP probably isn't a big deal. Even if I can't feel the extra 20lb/ft of TQ at 2000, it's probably a better option it than the extra 20 HP at 5000 RPM.

Considering the stock specs were something like 133HP and 250lb/ft torque, it should work and feel much better @ 275 HP and 335 lb/ft torque.

Thanks again.
Rem

 

Get Ford's "The official 5.0 Manual" published by Ford Racing. The block weights are in there along with lots of other specs for the 1980-up 5.0's along with some info for the earlier 302's. The D8VE- A3A blocks with the thick main caps I've run across on my own. I've had others come up with these blocks too on a few forums after seeing me mention them. The bunch I weighed (bare) were some I got with a bunch of Bronco parts and stripped down to scrap and sell the usable parts. Just out of curiosity, I weighed those 4-5 blocks to see how they compared to the Mex block weights. The only thing special about the Mex blocks was the main caps, they're otherwise the same as far as weights as the rest of the early, pre 1980 blocks.

 

This one below linked on Amazon?


I purchased two SBF books, and they're decent enough for casual reading, but kind of a generic overall, and focused mainly on 1980-older stuff.

Does the Official 5.0 manual make any reference to what the CC volume is of the 4x valve reliefs in my flat-top pistons?

I've found varying info online. I've read that the pistons in the 87-93 5.0 engines, with the slight dished section in addition to the valve reliefs was 5cc, but I also came across info stating they were 5.5 cc, and 6cc. I found other comments that the true flat top pistons with 4 valve reliefs were 4.6cc, and 3cc.

 

Yea, that's the one. No mention of the relief volume, but just looking at the ones you posted, I'd say 3 cc's. The aftermarket reliefs are larger and spec out around 4-5 ccs. That's the volume I use in calculations. Then add 1 cc for the area around the piston to the wall and down to the top ring. Your volume for the .014 down the hole would be around 2-3 ccs based on a .046 head gasket volume of 9 ccs. So for yours I'd say 3+3+1+9+64= 80 ccs, then add that to 617.8 for the swept volume, then divide the result by 80ccs to get 8.72, which is close to the 8.8 you or Conanski mentioned. Mill your heads .040 that will get you a little over 9 to 1. I would not deck on that block at all more than necessary to get the surface cleaned up. I have a couple of friends that run dirt track cars and they avoid those blocks at all costs because of the thin decks that result in gasket sealing issues.

 

Thanks for the info, much appreciated. I've read that, with the GT40 heads, approximately every 0.007" machined off equals 1cc. Does that sound about right?

According to my math, 0.007" in a 4" bore equals 1.44 CC, but the area of the chamber is only about 2/3 of that, so the 1 cc per 7 thou seems correct...at least in the approximate sense.

 

The correct volume per amount milled is listed in that book. I don't have my copy with me to look it up right now. But If my memory is correct, that's about right. A .040 cut would get the chambers to 60 ccs. I milled the Canfield heads on my 331 .060 and that reduced them from 64 ccs to 57 ccs. Of course the chambers are different than the GT40 heads. That book had the most complete info on the 1979-up 5.0's of any book I've run across

 

As for the other books on the older Ford engines, you really have to buy and read all of them to find the mistakes in them. And there are a few mistakes. The Ford racing book may have some too, but I've yet to see anything obvious in it. It may be written by the author, but the info I assume was sanctioned by Ford looking at it's title.

 

These are the two that I have now:



They've been very helpful, but they're just kind of a generic read on the basics. There are some good details, and a few pages of specs here and there, but I found a couple mistakes myself. They really are aimed more at the pre-roller block era SBF's, and more specifically at the 1970's stuff. I'm not complaining...as a new guy with this stuff, they were good reading to get up to speed on the basics.

Thanks for all the replies/help. Much appreciated.

I'll report back with details after this thing is assembled and tested.