www.ColoradoClassicBroncos.com

Digger wrote:Your trip to Mt. Evans looked awesome.

Yes, congrats!! Glad it went well, except the body damage. But, you ain't pushin' hard enough if you have a clean body!

Viperwolf1 wrote:That's an oil drain hole.

You won't find many flat tappet cams with 114 lobe separation. You can find some that give better low end torque than the CR266 though which is probably what you want. Here is a comparison between the CR266 and Comp X4254H. It's only 111 degrees lobe separation but it give a good torque increase under 3700 rpm.

Justin 351w.jpg

I think I'm going to order this cam. Do I need to upgrade the valve springs? Currently have GT40 heads with stock springs, which I know are regarded as weak.

Dropped my third member today to see why my rear ARB was non-functional. Found a problem. Fitting was probably fairly old. Never seen an ARB with a blue plastic air hose internally. Anyone know if that's how they were set up back in the day?

Justin wrote:Dropped my third member today to see why my rear ARB was non-functional. Found a problem. Fitting was probably fairly old. Never seen an ARB with a blue plastic air hose internally. Anyone know if that's how they were set up back in the day?

Plastic - yep...That's how my ARB is setup...and my Bronco is ole school for sure.

Erik

That's some 1st Gen ARB there.

Picked up my heads from the machine shop yesterday. I'd thought they were Explorer heads, but it looks like they're actually off a Cobra or Lightning, as they were already drilled for a 351w and the casting numbers indicated that they're somewhere around 61cc. Have to give a big shout out to Western Engine, as they IDed them, steered me right on whether they should be milled down, and then did a great job for a very reasonable cost and fast turn around. These guys will be my go-to for any future engine building projects.

Early GT40s were said to have the larger head bolt holes and smaller chambers. This being said go have been the case because they were left overs/replacement parts for the Lightning line left on the shelf when the Triton motors came on line in 97.

I see your F3ZE-AA part number. Is the casting date still visible after the milling? I can almost make out a "?609" on the top of the right head.

SCORE !!!
I just had the XJ head reworks by Western 6 months ago. I really like their service/work.

Justin wrote:Picked up my heads from the machine shop yesterday. I'd thought they were Explorer heads, but it looks like they're actually off a Cobra or Lightning, as they were already drilled for a 351w and the casting numbers indicated that they're somewhere around 61cc. Have to give a big shout out to Western Engine, as they IDed them, steered me right on whether they should be milled down, and then did a great job for a very reasonable cost and fast turn around. These guys will be my go-to for any future engine building projects.

Same GT40s as Eck.

akaFrankCastle wrote:I see your F3ZE-AA part number. Is the casting date still visible after the milling? I can almost make out a "?609" on the top of the right head.

It's 6090.

Justin wrote:

akaFrankCastle wrote:I see your F3ZE-AA part number. Is the casting date still visible after the milling? I can almost make out a "?609" on the top of the right head.

It's 6090.

Yeah, I'm an idiot. That's not the casting date. It should be on top of the head, in the rocker area. Will look something like this.

Here's what I've got. The first one is 26A6.

January 26, 1996
Cast on a Friday.

June 5, 1995
Cast on a Monday.

akaFrankCastle wrote:January 26, 1996
Cast on a Friday.

June 5, 1995
Cast on a Monday.

How do the codes work? Would love to know when mine were done.

Sent from my HTC One using Tapatalk

phyler wrote:

akaFrankCastle wrote:January 26, 1996
Cast on a Friday.

June 5, 1995
Cast on a Monday.

How do the codes work? Would love to know when mine were done.

Sent from my HTC One using Tapatalk

6A26 is translated as such:
6: year within the decade
A: month of the year, A=1st letter, 1st month is January
26: day of the month

http://www.mustangtek.com/FordDecode.html

akaFrankCastle wrote:

phyler wrote:

akaFrankCastle wrote:January 26, 1996
Cast on a Friday.

June 5, 1995
Cast on a Monday.

How do the codes work? Would love to know when mine were done.

Sent from my HTC One using Tapatalk

6A26 is translated as such:
6: year within the decade
A: month of the year, A=1st letter, 1st month is January
26: day of the month

http://www.mustangtek.com/FordDecode.html

Thanks! I figured it was along those lines but wasn't exactly sure which order.

Sent from my HTC One using Tapatalk

Interesting. The date would suggest that they're not cobra or lightning type heads since they're cast after production of both ended. So why would they have already been set up with 1/2 holes for the head bolts?

I've seen quite a few early 97 Explorers that had GT40 heads with 1/2" bolt holes. I have no idea why though.

Huh, odd. Any idea on combustion chamber size?

I've heard everything from 58-66cc depending on the source. Most seem to point towards 64.

Shoot. Sounds like I need to try ccing them again to confirm it.

Finally got some time to wash and paint the block. Still needs some work with a razor blade, but it came out nice. After some reading, decided on the earlier Ford blue with cast aluminum/silver front dress and intake. Haven't decided about the timing cover or heads yet, but am leaning towards the blue. Need to get the pan and valve covers in for blasting and figure out whether I'm going to spring for a different cam, then I can start getting this thing built!

That's looking good. Can't go wrong with Ford blue.

Viperwolf1 wrote:That's an oil drain hole.

You won't find many flat tappet cams with 114 lobe separation. You can find some that give better low end torque than the CR266 though which is probably what you want. Here is a comparison between the CR266 and Comp X4254H. It's only 111 degrees lobe separation but it give a good torque increase under 3700 rpm.

Justin 351w.jpg

OK, cam decision time, as I'd like to get this engine build moved forward. Realistically, how much difference in actual use will I see with a switch to the Comp cam over the CR266 I've already got? I'm inclined to save the $150, but if it's something I'd notice I'm willing to spend the money. Any advice?

Justin wrote:

Viperwolf1 wrote:That's an oil drain hole.

You won't find many flat tappet cams with 114 lobe separation. You can find some that give better low end torque than the CR266 though which is probably what you want. Here is a comparison between the CR266 and Comp X4254H. It's only 111 degrees lobe separation but it give a good torque increase under 3700 rpm.

Justin 351w.jpg

OK, cam decision time, as I'd like to get this engine build moved forward. Realistically, how much difference in actual use will I see with a switch to the Comp cam over the CR266 I've already got? I'm inclined to save the $150, but if it's something I'd notice I'm willing to spend the money. Any advice?

If you already have the cr266 it's probably not worth the expensive to get the comp cam.

Cool, thanks. That was the way I'd been leaning

Spent some time making the house smell funny today.

Shiny!

Looking good Justin