First step is to mock it all up and see what she does. Cover the tip of the valve with something so you can get a mark. I usually just color it with a felt tip marker and then rotate the engine a few times to see what kind of witness mark is left. You can also tell a lot by just observing how the rocker moves across the valve tip. You'll probably have a problem with the hyd roller lifters if you are using the actual springs but they should work okay with checking springs. To see how it looks with the actual springs you might need to use a solid roller lifter.

Quote from: andyf on May 10, 2018, 10:07:23 AM

If you are handy with calculus you can figure out the location that gives you the lowest combination of load and travel. The Mid Lift setup gives the minimum travel across the valve which is fine for low load springs. But if you have high load springs, the load at full lift is much greater than it is at low lift so you might want to reduce the amount of sideways travel near full load.

Mid Lift gives you max travel at full load which might not be good for things. It takes some advanced math to figure out but you can minimize the product of load and travel by moving the shaft down. You do end up with more travel across the valve, but that extra sideways travel occurs at the beginning of the lift cycle when the rocker arm is lightly loaded.

I'd like to understand this more. What Scott's last post and his video illustrate make a ton of sense, but then if you're building something a bit more high-end and high lift, this also makes sense.

I may have to do the math and build a spreadsheet....I know you guys love my spreadsheets.

Yeah you can find the answer with a spreadsheet. Just have to iterate it a few times. The answer will be around 2/3 lift for the point where the rocker arm is perpendicular to the valve. If you have an old Chevy Power book you'll find an explanation on the low mount theory. The Chevy engineers figured this out a long time ago and it is what they recommended back in the day. I think Jesel adopted the Chevy engineering theory but I don't know for sure. You would have to ask Wayne why he did what he did.

I guess I'm just the opposite. I'll use Molnar stuff but not Crower. Crower makes great stuff but I've found that they are just too difficult to work with. Tom on the other hand is a pretty good guy to work with and he sells nice parts. I've also had great luck working with the guys at SCAT. They've done custom cranks for me that Crower turned up their nose on. Oliver is also pretty good to work with and they can build anything you need.

At my point in life I don't really care which country the part is made in since that is a pointless discussion. Where did the iron ore come from? Who did the CAD work? Which country was the inspection equipment made in? Country of origin is a meaningless concept if you dig into a few levels. Everything comes from everywhere.

I'm a lot more interested in who I'm dealing with and will they support their product after the sale. Will they work with you to get you what you need? I don't really care where the vendor sources the raw material, that is their business. Besides, how much of your original FE engine came from USA? Detroit has been sourcing parts from around the world for a long time.

I think one of the best things I ever did with the dry sump setup was to install a sight gage on the tank. In the dyno cell we set up a video camera to watch the sight gage. That tells us if the dry sump system is pulling oil from the engine or if the oil is getting trapped. If you don't have a way to watch the oil level in the tank during a pull then you don't really know what is going on. I have a buddy who took his dry sump engines to the salt and burned them down. The oil was filling up the valve covers and after a couple of miles he lost pressure. Had he run the system on a dyno with a video camera he could've saved himself a lot of time and money.

I put a window in one of my big dry sump pans just to see what happens at various vacuum levels. I've tested really large dry sump pans and super small dry sump pans just to see what the difference is. I've run dry sump with a vacuum pump and without. Lots of various stuff to test with dry sump setups and I'm sure I haven't done 1% of the testing that the NASCAR boys have.

I've been running a six stage on the SOHC in my Shelby clone for the last several years.  Three pickups in the pan, one at the back of each head, plus the pressure stage.  I was told by the dry sump folks (Peterson Fluid Systems) that this would give me plenty of crankcase vacuum.  That turned out to be BS, it will deliver some vacuum at idle but not when the engine starts running at higher engine speeds.  I was always able to get 15 inches of vacuum with my GZ Motorsports vacuum pump.  For the cost, weight, and complexity of the dry sump system, and no crankcase vacuum to speak of, I'm very disappointed in it.  I'm going back to a normal FE oil pump and pan, a vacuum pump, and an accumulator (Accusump) to ensure oiling under all conditions.

Jay, are you using the new R4 pump design? I use a 5 stage R4 pump on my race engines and I can usually pull more than 10 inches. I'd think a 6 stage would pull a little more.

Quote from: Drew Pojedinec on April 11, 2018, 10:30:43 PM

If you live near Georgia/Florida, stop by.... we'll go for a ride   even with my 525? hp 447ci engine traction makes it to where I don't think any more power would be terribly useful without prepped pavement and competition tires.

Really appreciate the offer, but I'm in Seattle.  Womp womp.

Seattle isn't too far away, I'm in the Portland area. The 700 hp Car Craft engine will be in a '63 1/2 Galaxie this summer if you want to come down and check it out. The car is getting a new fuel system at the moment and some other upgrades. Should be running by the end of summer if everything goes smooth. Sounds like it will be pretty close to what you're building. I think the owner is going with a 3.50 rear gear and he had the C6 beefed up a bit.

A solid cam, dual carb, 700 hp big block will get old on the street fairly quickly unless you have a high tolerance for noise, vibration and maintenance.  However, you can tame the beast down fairly easily by going with a smaller cam and using EFI. A hyd roller cam will give up some power but cuts down on the noise and maintenance. EFI solves a ton of annoying issues with cold start, hot start, low speed response, etc.

The 700 hp 482 that we did for Car Craft is going in a '63 1/2 Galaxie and is going to be a "run around town car". I wouldn't be surprised if the cam gets downgraded a notch or two after the owner drives it for awhile. The great thing about EFI is that you can dial the tune in. Getting 2000 cfm of carb to play nice at part throttle cruise can be a real chore........

If you don't know exactly what your tolerance level is then I'd suggest building a big engine with safe compression ratio and good heads. That will give you a nice solid foundation to work with. Then you can experiment with different cams until you find a combo that is fun to drive. Changing cams on a FE is a pain, but that is basically what you are signing up for when you take on a project like this.