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464 Ram Air II Build
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Figured I'd kick off a thread for my build now that I've got most of the parts in my posession. Maybe it will help some folks in the future.
The backstory is in this thread. I pulled my engine in January looking to do a top end swap to some Ram Air II heads, RA IV repro intake and a roller cam. I found that all my bearings and crank were trashed from an incident early in the engine's life where the valve spring retainers ate the valve stem seals. So, I decided to build my dream engine - something that looks stockish but catches the eye of a Pontiac die hard when I open the hood of my plain jane '68. The rest of the car has a bunch of other stock looking tweaks for handling and drivability to go with the theme. I've done plenty of cam and head swaps over the years, but this will be the first time I've assembled an entire engine from ground up. I spent the last 9 months doing homework and rounding up the tools and parts required for this build. Here's what's the bottom end looks like:
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It's going in my '68 GTO, which I've owned since '91. The rest of the drivetrain is a rebuilt '68 TH400, 13" Continental stall, 2.5" Pypes stainless exhaust, 3.55 posi. https://forums.maxperformanceinc.com...1&d=1662070049 https://forums.maxperformanceinc.com...1&d=1662070061 https://forums.maxperformanceinc.com...1&d=1662070071 https://forums.maxperformanceinc.com...1&d=1662070078 https://forums.maxperformanceinc.com...1&d=1660954370 https://forums.maxperformanceinc.com...1&d=1635523975 https://forums.maxperformanceinc.com...1&d=1662071510 https://forums.maxperformanceinc.com...1&d=1651621992 |
COOL BUILD!
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A suggestion I have would be to deburr the lifter valley and pop for the added bucks for a lifter valley brace.
Yes, I know your not running a solid lifter race roller, but the tall hydro lifters still add more stress to the thin stock lifter bores , so why take a chance on loosing a nice block! One other thing I might note is the high exh to intake ratio those RAII heads have. The exh side of those heads on those heads flow right up there with what the intake ports flow, like 200 cfm@.550 lift, and that’s not even there peak flow either! If you ever step up to running headers on the motor You should change over to a single pattern cam other wise the headers will be a bit of a waste by over scavenging the motor and making jetting the motor right a good bit of a mess! |
So much goodness here. :)
But ditch the PRW rockers for something better like Harland Sharp aluminum or Crower Enduro stainless. |
So awesome but curious why you went with RAII heads (someone could use for a resto) as opposed to alluminum edelbrock? You can do what you want not giving you a hard time but curious.
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I'm starting off by checking the oil clearance on the rods and mains.
The Butler-supplied Clevite/Mahle CB-743HN bearings measured surprisingly consistent giving me .0019-.0020 clearance across the board. Consensus is that's good. The mains aren't going to be quite as easy. The dial bore indicator was showing only about .0015 clearance which is not enough. It takes substantial effort to spin it by hand too. I reached out to Butler, their suggestion was to forgo the Clevite MS-496P bearings they sent with the kit and try a set of King .001 extra clearance bearings, so I have those on the way. If those don't work out, I suspect I'm in for a trip to the machine shop. Quote:
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Good luck to you on your build. Sounds like a great build. I agree with B-man on the rockers. Cliff and someone else on the forum have had problems with PRW's.
Always glad to see another "68 getting a nice build. |
Very nice combo in the making.
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I`m running Road Paver without a brace. Has been past 6000 rpm`s many times.
Get the thickest one piece pushrods you can find. Smith Brothers comes to mind. Check length! I believe a lot of problems on this board could be the wrong length pushrods, especially running any roller cam. For example, mine came out to 8.900. So, way shorter than stock. |
I think a valley brace is overkill for that little cam.Tom
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The build I always wanted to do. Ended up with 7F6 heads.
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The RAII heads are what makes this engine a dream come true.
Aftermarket aluminum heads are great, but just not the same vibe as the legendary RAII heads. The first of the round ports. :thumbup: |
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I likely won’t ever have the means to afford a real RAII car (Mattison’s old blue RAII is my dream car), so I’ll make my own. BTW, no plans for the carb or hood pan. My car has A/C so it will be plainly obvious these heads don’t belong on the car…which I kind of love. |
I remember someone doing the homework on what the hood scoops and ram air setup flows, and it's marginal at best, even for standard engine offerings. There's no shame in not running it. A 14" element with the 3" filter will out flow the ram air setup every time.
Commented on the other thread about the crank bearing clearances, will add, check main journals on crank for out of round-ness. I suspect they are good, but is worth the comment. Also make sure the parts are 75 degrees for a day before you check. I have heard mixed reviews on the PRW rockers, but believe the issues were early on in production, and were resolved. I personally would not use them, and spring for crowers, but that is just my SOP. On your build and power level, these days I wouldn't think twice about running them. Do a scrutinizing visual inspection, before & after install, and if all is good, let it rip. Nice build. It's a popular, proven combo with repeatable results. It's pretty hard to go wrong with it. I personally would do the Road Paver, but nothing wrong with the OF. Very forgiving and easy to tune, with plenty of vacuum to support whatever. Pushrod length check is SOP for every build, and not much effort to do. Check guide hole opening with it mocked up, and touch up as needed. Check intake bolt holes too, mark the center of ports is optional, but recommended. I usually use a triangular file, notch the mating flange, and do a punch mark close to the valve cover gasket rail. If you need to adjust, the intake bolt holes need to be large enough, as well as the ridge on the timing cover gasket area. . |
I tip in regards to the port match to get your heads set up to your RA4 Intake is this.
The roof of the heads need to level and match the Intake Manifold height for 1/8" passed the end of the push rod bulge . From there on back into the Intake runner the roof needs to taper back down at the same rate that the floor rises pretty much. You should use inside snap gauges for this or make a still cardboard template once you do one so that all the others are the same. While you have the grinder in hand you should cut back the push rod bulge so the width top to bottom is .960". PS. A buddy of mine had to ditch those PRW rockers also. He was lucky that they started to make noise while loading the car in the race trailer and on the first time shot at the track! |
REALLY cool build and beautiful car!!
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As long as your going for a good set of quality pushrods get them with a thicker wall section. See posts 3&4 here:
https://forums.maxperformanceinc.com...hlight=pushrod . |
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. :thumbup: |
I, (and you) would do well to copy(get a copy) of Mahoney's Ported iron Intake !! My 4234 iron awaits the recipe!
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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. |
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!
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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? |
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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.
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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. |
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.
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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. |
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! |
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. |
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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. https://forums.maxperformanceinc.com...1&d=1662163873 https://forums.maxperformanceinc.com...1&d=1662163999 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. https://forums.maxperformanceinc.com...1&d=1662163154 https://forums.maxperformanceinc.com...1&d=1662163163 https://forums.maxperformanceinc.com...1&d=1662163114 Quote:
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Vey cool, good luck getting her buttoned up!
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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. https://forums.maxperformanceinc.com...1&d=1662178884 https://forums.maxperformanceinc.com...1&d=1662178897 |
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. |
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. |
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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. |
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Check vacuum, see if it starts pulling vacuum over x RPM. My understanding is it's a flow restriction, and don't disagree that IATs would drop. I bet IATs drop even with an open element under the hood, as air starts flowing and evacuating from the underhood area, so think a comparison would be in order to determine the gains/improvements. . |
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I understand once psi starts to build with speed, they could flow more than a static 400cfm, but how much is the question. . |
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More I think about it, not sure data logging vacuum would show data required to determine if there's a restriction or not, but suspect it would be at least one data point. . |
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As an example, a ran the equivalent to the road paver in a car with PB & AC, no problems, at around 12-13" vacuum at idle. Granted, I did run a dual diaphragm 8" booster, but just to give an idea. Again, granted, that was with E-heads, but you could check, and adjust for the higher lift. . |
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Nice work by the way, and love the build!
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Always said Crowers are the only way to go, and that's all I use now. I just suck it up when comes to cost, and accept it's a cost required for a build. . |
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