[Half-Inch Stud]

I, (and you) would do well to copy(get a copy) of Mahoney's Ported iron Intake !! My 4234 iron awaits the recipe!

[jhein]

That sounds like a cool motor. I would go with a slightly bigger cam.

I waited almost a year trying to get Crower SS enduro rockers but had to give up and went with Comp Cams Aluminum.

[Jim Moshier]

This really does sound like a cool motor project looking forward to the results! Nice flowing heads don't need a bigger cam. JMO...... run what ya brung!

Jim

[25stevem]

HYWSTR455 this was like 5 years back and they where likely sitting around waiting for the heads to show up for 6 months to close to a year.

So the question then becomes, how does that one tell a improved set from the older ones?

[Bruce Meyer]

Originally Posted by Formulajones

I was one that did homework on the ram air setup. Dad bought his 69 Goat new and been racing it since the 80's. The car has always run it's best times with those scoops functional and the factory air cleaner setup in place. Had numerous 455's in the car during that period.

More recently in fact I've modified the setup with a Glasstek hood and molded in an air box using a L88 style drop base to seal the hood to only fresh outside air, still uses the GTO scoops. Basically it now mimics how the 68 style was setup. The car now has a 571ci. engine.
Now with a Sniper installed I can datalog. IAT's are the most telling. Pumping gas and sitting still getting heat soaked the IAT's are already 130 degrees after 5 minutes. Pulling out of the station and within a mile of cruising 30-40 mph the IAT's drop to within a couple degrees of outside ambient temps. You can actually watch the IAT's go up at a stop light, and come back down when the car starts moving.
At the track where the car traps 128 mph, during the datalog the IAT's are dropping throughout the pass and actually getting about 20 degrees below ambient temps at those speeds.

The setup works very well.

Either way I like the build. I like the 96 heads on the 68 GTO idea, and how I would have built it. Iron intake would be more correct for 68 but I much rather prefer the aluminum version with the separate heat crossover. I've been running it for a few years now on mine and was a big improvement over heat soak while still keeping the divorce choke functional.
Not a fan of the rockers as mentioned. I only use Harland Sharp or Crower steel rockers on my builds anymore. Otherwise a nice combo of parts that's going to be a blast to drive.

I put a 68 ran air setup on my 69 and went quicker by a tenth. That's around 10 HP. I used the 68 setup because its much simpler than the 69. I would like to see what one of those scoops flow on a flow bench. I bet each one flows well over 400 cfm.

[Skip Fix]

Crower SS are the best I have found bar none. HS are OK I have both on motors. And some Norris SS-not sure if they are still around.

[Formulajones]

Originally Posted by Bruce Meyer

I put a 68 ran air setup on my 69 and went quicker by a tenth. That's around 10 HP. I used the 68 setup because its much simpler than the 69. I would like to see what one of those scoops flow on a flow bench. I bet each one flows well over 400 cfm.

Interesting question, I don't know. They seem to flow enough to support dads car fine with the 571 in it.

He ran the 69 setup up until he decided to install a Glasstek replica hood. No more flappers in the scoops. So I cut the scoops open, molded in an air box and use an L88 base, so it basically functions like the 68 version, and works excellent on his car.

[jhein]

I still vote for a bigger cam. The RAII motors were designed to work with a 041 cam and a 400 cid, no? So if you have ported heads and 64 more cid I'd think it would be begging for a bigger cam.

[Verdoro 68]

The heads aren’t ported, just gasket matched.

This cam is probably a little on the conservative side, but seemed like a good match to the rest of the combo. I’m probably not going to change it, but curious what you’d run.

[25stevem]

The 68 Ram air system did not yet have the provision to open and close the hood scoope’s as in the 69 and 70 system.

Without those flaps and the bar they mount to acting like a throttle blade and cutting down on flow there’s no doubt that the 68 system passed more air.

The statement of 400 cfm worth is pushing it judging by the amount of square inches of opening my eye see’s on my 70s hood!

[jhein]

Well, your combo seems very similar to mine. Similar cid. You have unported RAII heads and I have unported Edelbrock D-port heads. You're 9.5 CR and I'm 10. Both 1.5 rockers. So I'd pick the cam I have which is the Comp Cams/Butler custom grind 236/242 520/540 on 112 lsa.

And since I'm not an expert at all, I based that on what people here have posted, and Butler's advice, and of course my engine builder.

But, it still depends on what you want. Like when I was putting together my combo, lots of people suggested 1.65 rockers. That would definitely get me more power but by my estimation, I'm already going to have a little more than I really need for my purpose. Anything more would be total overkill. It still may be overkill. But I decided that I'd rather have a little more than I need than a little less.

The Dyno will tell the tale very soon.

[Bruce Meyer]

Originally Posted by Formulajones

Interesting question, I don't know. They seem to flow enough to support dads car fine with the 571 in it.

He ran the 69 setup up until he decided to install a Glasstek replica hood. No more flappers in the scoops. So I cut the scoops open, molded in an air box and use an L88 base, so it basically functions like the 68 version, and works excellent on his car.

We can figure out how much they are flowing for your fathers cars needs. We can use a formula to find out how much HP he is making by knowing the ET. and weight of the car. Dyno #,s will work too if you have them. Once we know that we can calculate how much CFM is needed to make that HP and finally put this nonsense of the scoops being too small to rest.

[Formulajones]

Originally Posted by Bruce Meyer

We can figure out how much they are flowing for your fathers cars needs. We can use a formula to find out how much HP he is making by knowing the ET. and weight of the car. Dyno #,s will work too if you have them. Once we know that we can calculate how much CFM is needed to make that HP and finally put this nonsense of the scoops being too small to rest.

I can send you the info via pm if you wish. You're welcome to take that and plug it into any formula and see what it comes up with.

[Verdoro 68]

The extra clearance King main bearings (MB5511XPSTDX) got here today, and I had the day off, so I spent the afternoon in the garage prepping the block and fiddling with the crank clearance.

The first thing I did was carefully clearance the block for the stroker crank counterweight. Tin Indian says they go for about .080, so that's what I did.





After that, I cleaned the block and went back to fitting the crank. The King bearings loosened things up exactly as advertised. I'm now on the tight side of the spec Butler provided for bearings 1-4, but the rear main cap seems to have much more clearance at .0034. I'm using ARP's torque recommendation for the studs w/ ultra torque lube - 110 ft/lbs on 1-4 and 140 ft/lbs on #5.

1: .0025
2: .0025
3: .0024
4: .0024
5: .0034

I double checked all the mains with plastigage, and they came out to within the ballpark I measured. The rear main looked a closer to .030 with the plastigage, but I trust my mic and the dial bore over it.

I put the Clevite back in and measured at .0015 - as it did the first time. I swapped shells back and forth and remeasured several times and got the same results. As a last resort, I measured the thickness of the shells and the King is .001 thinner than the Clevite (.0974 vs. .0984), that's probably where the .002 difference came from.

So I guess the question is, do I get a standard King set to see if I can get the #5 journal in line with the rest or roll with a looser journal?

With the mains all torqued down, the crank spins easily when you grab it by the snout. It's not a "two finger" spin like Cliff mentioned in an old post, but it takes very little effort. I couldn't even get the in-lbs it took to spin it to register on my digital torque wrench. No indication of tight spots from a few spins around.

Originally Posted by jhein

Well, your combo seems very similar to mine. Similar cid. You have unported RAII heads and I have unported Edelbrock D-port heads. You're 9.5 CR and I'm 10. Both 1.5 rockers. So I'd pick the cam I have which is the Comp Cams/Butler custom grind 236/242 520/540 on 112 lsa.

And since I'm not an expert at all, I based that on what people here have posted, and Butler's advice, and of course my engine builder.

But, it still depends on what you want. Like when I was putting together my combo, lots of people suggested 1.65 rockers. That would definitely get me more power but by my estimation, I'm already going to have a little more than I really need for my purpose. Anything more would be total overkill. It still may be overkill. But I decided that I'd rather have a little more than I need than a little less.

The Dyno will tell the tale very soon.

Curious how you net out here. I could probably get away with that 236/242. I kept it conservative due to the A/C and power brakes. I also had my eye on making sure the retainers would't hammer the valve spring seals with a higher lift cam, like they did on my #16s. I could be wrong, but I think you can get away with more lift on the Edelbrocks?

[will slow gto]

Vey cool, good luck getting her buttoned up!

[Verdoro 68]

I closed up shop for the day, but the #5 bearing situation was bugging me. Then, I came up with an idea test my hypothesis. I set up #5 with 1/2 a King and 1/2 a Clevite. Sure enough the clearance was at .0025 on the nose. Guess I better order a set of standard King bearings...just for #5.

I'm thinking about ordering a set of King rod bearings to keep things consistent, but the Clevites Butler sent are right on the nose for clearance, so maybe I'll let sleeping dogs lie. I do like the coating on the Kings though, it's more resilient than the Clevite coating.

[Dragncar]

Cool build.
Those rockers are known for putting metal filings in your oil.
I would not risk it with a Eagle cast crank.
Go Scat 4340 , worth every penny.

[77 TRASHCAN]

It looks to me like you on your way towards final assembly?
Do you have intentions of zero decking block (I hope!!!)
I will never build another engine without getting the quench, spot on, it can make a huge difference in octane sensitivity. Iron heads need this more than alum heads.

I agree with other, a forged crank would be my only choice. The next step up in cam selection, seemingly, has been used by man without affecting drive-abilityat all.
I'm on board withCrower or Harland Sharp rockers, both can be bought direct from their factories.

[HWYSTR455]

Originally Posted by Formulajones

I was one that did homework on the ram air setup. Dad bought his 69 Goat new and been racing it since the 80's. The car has always run it's best times with those scoops functional and the factory air cleaner setup in place. Had numerous 455's in the car during that period.

More recently in fact I've modified the setup with a Glasstek hood and molded in an air box using a L88 style drop base to seal the hood to only fresh outside air, still uses the GTO scoops. Basically it now mimics how the 68 style was setup. The car now has a 571ci. engine.
Now with a Sniper installed I can datalog. IAT's are the most telling. Pumping gas and sitting still getting heat soaked the IAT's are already 130 degrees after 5 minutes. Pulling out of the station and within a mile of cruising 30-40 mph the IAT's drop to within a couple degrees of outside ambient temps. You can actually watch the IAT's go up at a stop light, and come back down when the car starts moving.
At the track where the car traps 128 mph, during the datalog the IAT's are dropping throughout the pass and actually getting about 20 degrees below ambient temps at those speeds.

The setup works very well.

Either way I like the build. I like the 96 heads on the 68 GTO idea, and how I would have built it. Iron intake would be more correct for 68 but I much rather prefer the aluminum version with the separate heat crossover. I've been running it for a few years now on mine and was a big improvement over heat soak while still keeping the divorce choke functional.
Not a fan of the rockers as mentioned. I only use Harland Sharp or Crower steel rockers on my builds anymore. Otherwise a nice combo of parts that's going to be a blast to drive.

That's more recent than I thought and after the PRWs were corrected, maybe the were old inventory? I know many use the PRWs with no issues, but for some reason I thought the issue was related to the wheel pin? I will go back thru my notes, but that will have to be after I'm done moving, living out of boxes right now.


.

[25stevem]

If you just switched over to main studs without at least getting the main bore checked with a precision ground round checking rod or if not Aline honed then that’s why number 5 could be doing what your seeing.

Main studs pull on the blocks main Webb in a different way then do bolts!

Before you order up different bearings and if you still have the old rear main bolts, then I would install them and torque them up and see what might change with your bearing clearance.