Roger's Precision Engines

Forgot to post this, oops. The engine air supply fan for the dyno finally gave up, and with all the other new parts on the dyno, a new box fan seems appropriate. The ceiling vent above the dyno room doors goes to the duct work with the fan inside it. Air from inside the shop is moved through the duct into a large hose above the engine on the dyno. There is a large fl**ge at the end of the hose that sits on top of the air flow bonnet, which is on top of the carburetor. There are holes around the perimeter of the fl**ge. This allows air to pass through the duct work and keep the hose and duct from getting heat soaked. This is pretty much what Superflow has in their cell blueprints. So the box fan is not forcing air into the engine. It is merely supplying the engine with clean air under neutral pressure instead of hot dirty air from inside the test cell.

The water brake and starter assembly are back together and reinstalled. The original water supply pump is now the return pump that is triggered by a float switch in the tank under the water brake. There is a much bigger 3-phase motor and pump that is now being used as a supply pump. A 500-gallon fiberglass tank has now replaced the old rusted metal tank. It has 450 gallons of water with 50 gallons of green antifreeze concentrate added to it, so no more heatingstrips, insulation, or corrosion. Should have an engine running on it tomorrow afternoon. Hopefully, it all works well.

SOLD

We built this Ford 300 6 cylinder for a customer 5 years ago. He died the day that he was coming to pick it up, and his family didn't want it. It really needs a new home. It came out of an early 90s F150 efi truck. We bored and honed it, balanced rotating assembly, mild comp hydraulic camshaft, valve job, and air injection ports have been plugged. I'm asking $2200 for it, and you can keep the motor feet. Contact the shop if you are interested.

Seasons Greetings!
The shop will be closed from Christmas day through New Year's day so our staff can spend some time with their families and friends. We will return next year on January 2nd, 2024. Thanks for your support throughout the year.
Have a very Merry Christmas and a Happy New Year from Roger's Precision Engines!

I was attempting to fix a minor water leak on my dyno, and it turned into a bigger water leak, and that turned into a full dyno disassembly including replacing a bunch of corroded parts and new bearings throughout. I guess 30+ years of water in an aluminum tank will do that. Here's some pictures of the old parts and their new replacements.

Last time this was taken down was 20ish years ago when Wally Duncan was alive and running the place.

We should be all back together and running again soon, hopefully.

Remember, Racecars need engines!

Here are the dyno results on the mild 462. It idles with 14" of vacuum with a slight lope. We put dome pistons, a different hydraulic flat tappet camshaft, and an RPM air gap intake on it. No port work on the Oval Port heads or extra magic pooky stuff on this one. It's going in a chevelle with a 4 speed muncie and should be fun with all that low speed torque. And runs on pump gas.

Something different for us, we are building a mild big block Chevy for a customer who has used us for many years going back to Wally in the 80s. It's a .040" over 454 with .200" dome pistons and 049 oval port heads. It's running a small Erson hydraulic flat tappet camshaft and RPM air gap intake manifold. Upgraded to 3/8" pushrods and roller tip rockers. Should have it on the dyno soon to break in the camshaft.

May 1st through 5th the front counter will be closed due to a lack of staff. There will be limited phone service too. Everything will be back to normal on May 8th.

Something a little different today. Ford 427W with a 8-71 Hampton supercharger and two AED 750 blower carbs.

Warren Wright welded the V-band conversion fl**ges onto the bigger exhaust housings. Since these are divided housings going on open fl**ges I decided to sandwich a divided fl**ge between the turbos and fl**ges. I rounded the center divider one one side of each fl**ge, hopefully this will make the transition smoother. Need to get some longer bolts and wait for the dyno to free up.

I ran my LS3 with the turbos all hooked up. Everything functions and doesn't leak but the turbine housings I was trying are too small and making tremendous heat from the headers. And the oil temperature was about 50°f hotter, over 200°f vs barely 150°f. Most of the color in the headers was from idling and light load during warm up. I have the wastegates dialed all the way down to 5 psi while I figure this thing out. I tried loading the engine for a light dyno run and around 40% throttle it had 5 psi boost and exhaust was blowing out the wastegate dumps like a backpack blower, every hanging on the walls was moving around. So I backed off throttle to 35ish% and 4 psi to close the wastegates. It made had 530 ft-lbs for a long ways and over 500 hp...at just under 40% throttle. Remember it made 499hp/490ft-lbs at 100% throttle naturally aspirated. I didn't think to print out that test, oops. The engine has to come off the dyno so we can run a few customers' engines.

I'm going back to the original exhaust turbine housings with 1.35 a/r ratio and found a weld on fl**ge that fills in the goofy grove and makes it a 3" v-band, which I conveniently have downpipes already made in. I'm not trying to make lots of boost (10 to 15 psi is plenty for this build) so I think the more open housings will work better for low boost and won't be dumping out the wastegates frequently. And hopefully less heat build up in the engine compartment of Swampthing.

Round 2 of turbo dynoing when more parts show up!

I'll give you some back story on the twin turbo project. This is going to be long. Lol.

Back in the late 90's I thought it would be cool to have twin turbos on my Frankenstein square body truck nicknamed Swampthing. I already had a 454 LS6 Big block and had aquired two Air Research T04B V-trim turbos. I ended up acquiring a B&M 420 Megablower and Superchiller and installing that in a boat.

Fast forward a couple decades and technology has advanced a lot. After selling the 413 Small block from Swampthing it needed a replacement and a recently aquired used LS3 all aluminum Gen 4 Small block seemed like a great idea. And I could resurrect my twin turbo plan. If you have been following the LS3 build than you already know what's been done to it.

I found cheap twin turbo headers and T4 elbows and wastegates and blow off valves online. The turbos had to have the turbine housings changed from divided 1.35 a/r ratio with odd downpipe attachment to open .68 a/r ratio with 4-bolt downpipe fl**ges. Injectors have been changed to Siemens Deka 80lbs, if that's not enough I have SEP 150lbs. I have a 2.5" in, 4" out intercooler...but it turns out to be 3.5" out...of course I already bought hoses. Oops.

The stock coil pack location doesn't work with the budget headers, I guess you get what you pay for. Lol. So coil brackets, wiring harness extensions, plug wires with 90° boots, wastegate & blow off valve hoses/fitttings, and intercooler hoses/clamps have been ordered.

Hopefully running with turbos Monday and I don't melt it down while tuning. Feel free to ask questions...??

Making progress with the turbo plumbing. Still a ways go.

I'm done with naturally aspirated tuning on my LS3. Tried timing from 22° to 30° and air/fuel ratio from 12.2:1 to 13.0:1. It made best power with 28° timing and 12.8:1 air/fuel ratio:
491 ft-lbs @ 4500
499 hp @ 6200
I think if you left the compression at 10.5:1 instead of lowering it to 9:1 like I did and with a similar camshaft it would be in the 520 to 540 hp and torque range. Which would be plenty but NOOOO...I had to go with twin turbos for some reason. Lol

Next to figure out turbo plumbing.

I got the stock LS3 intake and injectors installed on my LS3 and Holley Terminator X Max to operate it. The long runner efi intake was about 50 ft-lbs better from 4100 to 4600 rpm. And the peaks moved down around 500 rpm. It also gave up 20 hp above peak horsepower. I'm posting a video of it making a pull. Also have a video of it idling through the dyno mufflers, it has a slight lope, which I'm not disappointed about. Lol

I had installed the super big Melling 10355HV on the LS3 because of more bearing clearance, piston squirters, and 2 turbo oil feeds. Turns out that pump is 53% bigger than the LS6 pump and is for VVT & DOD applications. I had the yellow spring in the HV pump and installed the black spring and 2 shims in the LS6 pump. I also installed the ATI damper for my front drive kit. I ended up with 75 to 80 psi making a pull and around 50 psi idling @ 1000 rpm.

501 hp @ 6600 rpm.
455 ft-lbs @ 5000 rpm.

Now switching to EFI.

Made a couple dyno hits on the LS3 tonight but quit early due to excessive oil pressure, around 120 psi! Oops! But it did make:
452 ft-lbs @ 4800 & 5100 rpm.
494 hp @ 6200 & 6300 rpm.
I'll get the oil psi addressed before the beating continues.

Close to start up on the LS3 for my K10. Should have carburetor power numbers soon. Then on to Holley Terminator X EFI.

NHRA rulebooks from 1965 & 2022. They've added a couple more rules...

Corvette LS3 accessory drive kit installed. Need to add vent line return and temp sender to waterpump. Mock up the headers & turbos next.

I've been out sick for the last week and finally got back to work today. Stock valve covers and coil packs bolted in place. Going to start with carb intake to get a baseline and make sure everything mechanical is fine. Then switching to stock LS3 intake and injectors. Using Holley Terminator X Max and try tuning it n/a. After that it's time to start plumbing for twins!

The LS3 that we installed the oil squirters on is coming together. It has dished JE pistons for 9.3 to 1 compression and a Summit LS camshaft (SUM-8720). It's a small camshaft but this is going in a heavy street vehicle without a high stall converter. Also replaced the stock oil pan baffle with an Improved Racing trapdoor baffle for better oil control. Also had Warren Wright weld in oil return bungs.

Do you need piston squirters for your boosted LS project? We've got you covered! Installed though the mains which keeps them away from the rotating assembly and helps keep your pistons cool.

We now have L, XL, 2XL, & 3XL t-shirts in stock!
$20 each.

We got in an order of 2XL and 3XL t-shirts. Those of you that asked for them, here they are!