DaleTx

I did this custom engine build to try something different, and see what the engine builder could do with a set of Z06 LS7 heads and the GMPP LS7 single plane intake set up with port fuel injection on a LS 427” engine. Most guys on this site are running the LS or Fast intakes on the Gen IV heads with great results (big HP, strong mid-range, and very street friendly)… there are lots of good threads here testing different cam designs for this set up.

I wanted to achieve the same thing but was willing to give up a little mid-range to have a higher RPM potential, and higher peak HP with the single plane set up. I was not looking for the biggest number on the dyno though. For this build the goal was for good “average torque” and “average HP” over the entire RPM range. I wanted the power to roll on smooth from the bottom, and have a long wide power band. I didn’t want it to hit to hard all at once. No way did I want a cam that made a big HP number but was low on torque and didn’t make power until 4K.

This project took about 12 months to build the engine; dyno test and tune the engine; test cold air intakes; test the fuel system; and install the engine in the car. I had the engine built by a professional and I did the engine and dry sump install in the car.

Final Results:
Peak HP was 672 @ 6,900 RPM. Peak torque was 566 @ 5,500 RPM. From 3,600 RPM to 7,200 RPM the average power was 542 HP, and the average torque was 526 lb-ft. The torque was 500 lb-ft starting at 3,600 RPM and was still at 500 lb-ft at 7,000 RPM!! I was happy with the results for the single plane set up. There were no big spikes or dips in the dyno graph. The power & torque were very linear. I know A.C. was prepared to try different cam grinds on this build, but I was happy with the first one he came up with

The one thing that doesn’t show on the dyno sheet is the performance from idle to 3,500 RPM. I was concerned about this and didn’t know how the engine would feel in the car. I can say now that it is strong and smooth from idle all the way up to the 7,400 RPM limiter, there are no flat spots. From 5k to 7k it is unreal power… accelerates very hard.

When I did an HPDE event last September on a two mile road course with a tight chicane, I was able to run the whole track using only 3rd and 4th gear (no over drive). The engine pulled 3rd gear from low RPM coming out of a very tight chicane with no problem (most cars shifted into 2nd on this corner). On the long straights it pulled smoothly up to 6-7K. The strong performance of the engine on the track was the true test to me.

In the end after all the testing with this combo on the dyno, we found out that the 90 degree elbow cold air intake set up killed power big time on my engine. I would say if you have a good method to get air into the intake with minimal restriction, then the single plane works great. I ended up using a cowl induction hood set up drawing the air straight into the TB. The single plane breathes really well this way and distributes incoming air very evenly to the cylinders through the 4 barrel TB. If you want the extra RPM and power on top then the single plane works well with the right combination of heads, cam, TB, and cold air intake. I run an SD tune on this set up.

Not sure what I would change if we could do more testing… maybe try a 110 LSA rather than a 112 LSA on the cam? I know there was a lot of thought put into this… the 112 LSA worked out great though. I’d be curious what the difference would be with ported L92 heads versus the ported LS7 heads?

Thanks to A.C. Nutter for designing and building this custom engine, and Bryan Nutter for the awesome tune, perfect . Also… Thanks to A.C. & Bryan for testing the different air intakes and fuel system.


Engine dyno video
https://www.youtube.com/watch?v=9vfKPg3rElM

Under hood & idle video
https://www.youtube.com/watch?v=RtK18KQ4ZN4

Short driving video
https://www.youtube.com/watch?v=qOecia2qX9g


I'm done with my build & install now. Please add to this thread with info about your LS build with a single plane intake set up (cold air intake set up, TB used, intake used, heads & cam). I’d like to find out about other set ups and results good or bad. Also... please add any information on dry sump pump set ups and oil tanks/plumbing.

DaleTx

I have not posted on here for a while since I finished the engine build thread. This past winter I replaced the old 4 speed Muncie with a new T56 Magnum transmission. Now I have the proper transmission to go with the new engine.

Last week I got the car out on the track with the new engine and trans set up. Here is a 9 minute long in car video I took out on the track with the new set up. The engine performed well and I'm happy with the results. The engine has a nice long wide powerband and pulls hard. I ran it up to about 6K on the front and back straights... about 125 mph. The peak power is at 6,900 rpm so I still had more in it... I just need to work my way up to get comfortable with the speed.

DaleTx

Here is some pictures of the engine installed







The single plane intake set up works good on the street and the track. If you have room for the single plane it is a good setup. With the single plane the mid range drops slightly, but the power on the top end is better.



One more video of the new engine on the track last Friday. I ran out of gas on the back straight on the last lap (5:18) and coasted all the way back to my parking spot in the pits!

CarlC

iTrader: (9)

You ran out of gas? Could you tell if any was left in the tank?

DaleTx

The fuel tank was completely empty. When I got back to the pits I added fuel and the car started right up. My fuel mileage with the new 427" engine was 3 mpg while out on the track. The fuel consumption was a bit of a surprise. I ran four 25 minute sessions on the track and used two full tanks of gas.

With my old engine (450 hp 350") I would use about 1-1/4 tank of gas to run four 25 minute sessions. Now I know I can't go out with anything less than 1/2 a tank of fuel. The fuel pump and controller worked fine.

LSX67RS/SS

Dale, I read through your post once again for inspiration....again thanks for the great detail....although one question, are you using a hyd roller or a solid roller. and if you're using a solid roller are you adj lash frequently?

DaleTx

Thanks... I am using a hydraulic roller on this build and it has worked out great. Also, I am running light weight valve train including titanium intake valves. The engine was run up to 7,400 rpm on the engine dyno, and the valve train was stable with the hydraulic roller set up.

I have run solid rollers in the past but they do require quite a bit more maintenance. When I ran the solid roller I would check the lash about 2-3 times per season.

Jimbo1367

So what rockers, lifters and cam lobes did you use?

thanks,
Jim

DaleTx

Hey Jim, The rockers are T&D shaft rockers 1.8 ratio. Ill try to find out more info about the cam and lifters that Nutter used. I've been running the engine hard for about a year now with no issues.

Jimbo1367

DaleTx,
Thanks. Bad *** car.

redlineit

X2.

Mikelly

Wanted to chime in and let you know that because of this thread, I actually bought a drysump pump and drive system from Nutter Racing. I was on the fence but AC worked with me on my questions and was a great guy to deal with. Mine is going on a 403 Stroker LS3 in a 1975 Datsun 280Z track car.

Mike

DaleTx

Hey Mike that's great... AC is a good guy, and has lot's of experience with the dry sump systems. Post up some pictures of your Datsun 280Z track car project here. I would like to see pictures of the car and the dry sump set up if you have them.





Update on my engine build:
Recently I had a failure of my timing chain tensioner (LS3 style). I caught the problem before having any catastrophic failure. I have since replaced the LS3 style "tensioner" with the LS2/LS7 style "dampener".


Here are some pictures of the failed part







I'm not sure how long I ran my engine with the broken tensioner. This last summer I ran the car at several HPDE events. If you watch the youtube video I posted (testing the LS engine part 1) you can actually hear the sound of the broken tensioner parts sliding back and forth and clinking on the side of the oil pan when I go into the corners!

Since having the failure I have done some research and found out some other guys have had the same problem. Evidently the tensioners do not hold up very well on engine builds using larger lift cams. If you are running a larger lift cam with more aggressive lift, then I would recommend going with the LS2/LS7 style timing chain "dampener". From what I have read, that is the fix.

Here is a picture of the LS2/LS7 style "dampener"


My engine builder replaced the "tensioner"with the "dampener" and also replaced the timing chain. The car is back together now and running good. I am lucky that I did not break a timing chain. Just an FYI for the guys on here.

67SS509

iTrader: (25)

Glad you shared this build. Great stuff! My LS7 is almost identical to yours right down to the intake and throttle body. Only difference is I have a 400hp direct port and compression is 12:1.

Couldn't find where you stated lift on your cam? Mine is 64X/65X with about the same duration as yours and 112LSA. My best RWHP NA thru a locked converter was 556. Have you ever had yours on a chassie dyno?

redefined

Great motor build and awesome looking car. Sexy engine bay!

I'm still new to the V8 world so here is my question. Why stick to a Carb and not go fuel injection?

Exidous

iTrader: (11)

It is FI. It's a single plane intake and throttle body.

DaleTx

Talked to Nutter today and he said the valve lift is .667". What lift are you running? I have not run the car on a chassis dyno... just the engine dyno.

Thanks... Like Exidous said... the engine is FI. I'm running a FAST 4 barrel TB, and single plane intake with port fuel injection.

Hey Jim... I know this is an old question.... but I talked to Nutter today and he said the rockers are T&D 1.8 ratio... the lifters were LS7, and the valve lift was .667". However... the the lobe type, and duration was confidential. I know he put a lot of time in designing the cam so I respect that. He said the custom cam used in my 427 is available for sale through his shop.





I made a new air filter base to utilize the cowl induction hood... wanted to draw in cold air from outside the engine compartment.


IAT sensor in the rear


Found a better sealing material recently




The engine ran fine when I pulled the hot air from under the hood... but runs a bit better drawing in outside air with the cowl induction set up.

LSX67RS/SS

Dale, looks great but we're expecting nothing else from you at this point....what did you start with when building the base? I'm looking to do something very similar but was wondering what options are out there.

thanks again....

Jimbo1367

Dale,
Tanks for the reply. I can respect the designer doesn't want to give his R&D away. Thanks for asking. Have you ever considered checking for the infamous LS7 bad valve guides ? You may not get this IF*** it's a byproduct to OEM rockers.


thanks
Jim

DaleTx

No problem... I purchased a bare LS2 block that had been freshly sleeved and machined with a 4.125” bore (Nutter had a program going where he was selling sleeved LS blocks on ebay). Then, the engine was built from scratch at his shop. The LS7 heads were purchased from GM in the raw form, and then machined complete; valve guides, CNC porting, etc.

All the machine work and assembly was done under one roof. Through this build method I was able to choose all the parts based on my budget. I had several meetings with the engine builder to talk about parts... and make choices. I spent the extra $’s for forged internals, shaft rockers, and light weight valve train (titanium intake valves) and a dry sump oiling system since I planned to track the car a lot.

I used a LS1 ECM, LS1 sensors, and had a custom wiring harness made to fit my set up. This was the first engine I have had built from scratch… and it was a fun process and worked out well. The final tune was done on the engine dyno. I highly recommend doing the engine break-in and tune on an engine dyno if possible.

Good luck with your engine build...

Thanks Jim. On the valve guide question…. my guides are good, and I’ve had no issues with excessive wear. I’ve got several thousand street miles, and six track days with no problem.

I have read that some guys are having problems with excessive wear on the valve guides. When I asked the engine builder, he said it just comes down to proper machining and set up on the heads.