434ci, MMS 265 heads, Super Victor intake, MMS solid roller cam - dyno results
 

Hello all,

I just finished a rebuild of my engine with Tony's MMS heads / cam / intake. Sharing the results here for anyone looking to do a similar build of LS7 heads with a single-plane.

Some background. I have a Pro-Touring Firebird that I use for autocross and track days. I've had the engine running for several years based on TFS LS3 heads and a Victor Jr. intake ported by Frankenstein Racing Heads (now Frankenstein Engine Dynamics). I've gone through a couple of iterations of the engine due to some issues related to oil flow/control, but it's been a capable engine for me, making 570-ish rwhp and 500 ft-lb of torque.

I have followed Tony's work for many years and have always wanted to try one of his packages for myself. This past spring I took my car apart to address some suspension issues, and I wanted to also address yet another oil control issue inside of the motor. Since it was going to be apart, I again considered moving from the LS3 platform to an LS7 platform. My hesitation in the past had been that there wasn't a good intake option for me, as I want to keep my function shaker hood of the Trans Am. The GMPP intake isn't known for being a very good performer, and the Mast intakes are too tall (or so I thought, more on that later).

Last year Edelbrock release a Super Victor intake for the LS7. After some research (more than I care to admit), I determined that it should fit my car just barely. I decided to buy one and take a chance, and that's what I got in touch with Tony. Since I wasn't completely certain of the measurements, nor how good it would be compared to the GMPP, I ordered both and sent them to Tony to take a look. He immediately told me the GMPP wasn't a good option and I would be better served to stick with what I had. But the Super Victor seems like a good platform for him to work with.

At that point, I ordered a set of his MMS 265 LS7 heads, his Yella Terra rockers, a cam which he speced, and scheduled him to port my Super Victor. I'll post the full specs of the engine below...

- LS9 block sleeved by RED and bored to 4.155"
- Wiseco 8cc pistons (target around 12:1 compression)
- Callies Compstar 6.125" rods
- Callies DragonSlayer 4.000" stroke crank (with 2.000" rod journals)
- Comp Cams solid roller cam with Tony's lobes (252/266, ~0.710" lift, 114 LS)
- Crower Solid Roller lifters
- Trend pushrods, custom length
- MMS 265 heads, 2.205" hollow intake, 1.615" hollow exhaust, PAC 1208 springs & retainers, 64cc chambers
- Yella Terra LS7 adjustable rockers
- Ported Edelbrock Super Victor intake and -8AN fuel rails
- Accel 1550 cfm 4150 throttle body
- Dailey 3-stage LS7 dry sump pump and pan
- Holley Tall valve covers
- Factory LS coils, MSD wires
- Holley HP-EFI ECU

Attachment 718156

The machine work and assembly was done by H-Squared Racing down in Houston. Halston did the previous build last year, so I took it back to him when I wanted to do this freshen / upgrade. When he took the engine apart, everything inside looked great which was a relief. The concern I had was that my fuel pressure was not continuing to rise with RPM when the engine was heat soaked (track day at COTA). About halfway through a session, it would stall at 40psi. As soon as it cooled down, it would have full pressure again. So I never lost pressure, but something inside of the engine was growing and allowing pressure loss.

We decided to look at a few areas during the rebuild. One was the lifters. The factory block has a rather large oil channel to feed the lifters. If the block was growing in this area, it certainly could be bleeding off a lot of oil. Another thing I found in researching was that the cam bearings could be allowing oil bleed when hot. So we looked to address these areas amongst others. I had Halston bush the lifter bores with Jesel bushings. This would limit the size of the oil channel as well as give us a more consistent bore size for the lifters, allowing him to hone them to a specific size.

We learned the hard way that pressing in these bushings can be problematic though. The shop has done this many times on other blocks, but the casting in the 5.3L blocks (what I previously was using) wasn't nearly as strong in the lifter bores. Unfortunately 2 of the 16 bores cracked when the bushings were installed to Jesel's specs. After a few attempts at fixing them failed, we decided to replace the block. Halston was able to source a damaged LS9 block which needed sleeves, and that worked perfectly since I was running a sleeved block anyway. A trip to RED and we had our new block. I'm happy about this change, as I think the LS9 block is a better overall block for my application anyway (better breathing between bays).

We decided when we started this build that we would dyno the engine before I took it back to make sure everything was where it should be. It was wrapped up a couple of weeks ago, so we scheduled the dyno session at the School of Automotive Machinists (SAM) in Houston for last week. On Wednesday, we had our day.

We ran into a few snafus during our dyno session that prevented us from getting as many iterations as we had planned / hoped, but we were able to do what we needed to. We ran the engine for a while on the breakin oil to ensure all was good there. No leaks, solid oil pressure, etc. We got it good and hot, and then we checked the rocker lash. Right at 0.010 to 0.011" as planned.

Then we changed the oil and put in the 5W30 that I will run in it, and started our tuning sessions. The second pull netted me 699 HP, and I could just see this being 1 short of the magic 700 number. I would not have been happy... :eek:

Fortunately the engine had a lot left in her. We were tuning on the Holley HP, which is great since that is what I will be running in the car. I will have a decent baseline to start from. After a few pulls, we were at 721 HP / 580 ft-lb of torque. By LS7 standards, this engine won't make the same levels of torque due to the shorter runners of the single plane intake. But it sure will carry HP on the top end. :)

Halston happened to have a 4500-base version of the Mast single-plane intake with him, so we decided to swap that onto the engine and see what it would do. This was far from an ideal situation, as we didn't have the correct intake gaskets to do so. We used an adapter set of generic gaskets which were about 1/4" thick, so we had horrible alignment from the ports from the intake to the head. I'm talking at least 1/4" off or more (with this intake you can see easily down to the valve, so it was obvious). Still, we decided to give it a try, so we bolted down a 4500 throttle body that SAM had on-hand and gave it a pull.

It was quickly obvious that the engine liked the Mast intake and larger tb. The Mast has as HUGE plenum by comparison to the Super Victor. And the runners are more even in length and tapered well. Recall that my Super Victor has about 10 hours of porting time in it as well. The plenum has been nicely blended, and the ports have been matched to the heads and tapered also as much as they will allow. So my Super Victor baseline is a more optimized baseline.

The Mast / 4500 combination was worth about 14 HP and 12 ft-lb of torque over the Edelbrock. But the really interesting thing is how well the combination carried the power at the top. We stopped all of the pulled at 7500 as that is as much as I will spin the motor in the car. But if you look at the plot below, you can see that the Mast was flat up top at that point.

One nice thing about being on an engine dyno is that we had a full 8 O2 sensors from which to take readings. There were 2 cylinders which read lean during our initial runs, so some of the tuning involved richening those up a bit with the Holley. Somewhat surprisingly, when swapping the intakes, that stayed the same. I don't think that was a fluke of the dyno, as we gained power when we corrected for this.

On the dyno and the HP EFI, we could see that we were starting to pull a vacuum in the intake at the higher RPM. We saw about 5 kPa (101 down to 96) as the RPM rose. With the Mast intake and 4500 TB, we didn't see any significant drop in the kPa.

I would have really liked to have tried a Mast 4150 intake on the engine with my TB to see what it looked like. The reason I didn't use the Mast in the first place was that I thought it was taller than it actually is. It turns out to be about 1/8" shorter than the Super Victor (for anyone who may care in the future). Given that, I would have chosen it if I had known as it is a much nicer starting point. By the time I paid to port the Super Victor, I would be around the same cost. Here is a picture of the Mast, the LS3 Victor Jr I was running, and the Super Victor I will run:

Attachment 718157

One more comment on the Super Victor while I'm thinking about it. As it came from Edelbrock, the bolt holes where you attach the fuel rails were drilled at the wrong angle. This caused the rails to see too high preventing the injector o-rings from sealing. I called Edelbrock about this but got nowhere with their customer service desk. We had to slot the holes on the fuel rails to push them further down to get a good seal on the injectors. I wish I had caught that before having the work done on the intake...

Ok, enough of my story. Here's what you all came to see: dyno results. I have overlaid 3 runs. Unfortunately the dyno operator didn't do but 1 full rpm range pull, and even that started higher than I wanted. We ran out of time to do more pulls, so I don't have something to show the low-rpm range very well. What I show below are 3 runs:

• Super Victor with 4150 TB
• Mast with 4500 TB
• Mast with 4500 TB full pull

Attachment 718155

As I said above, the Mast just carries power really well. The Super Victor does also, but you can see the effect of pulling a vacuum starting to hit around 6900 - 7000. While my car is not a drag racer, and while Tony doesn't promote his package to that world, I would think that anyone wanting to build a drag racer with a similar combination would really like the power up top this thing makes!

If anyone is curious about the car this is going into, here it is doing its thing... :)

https://imgur.com/VEybY0b.png

I run a T56 Magnum behind the engine with a Monster LT1-S clutch. The rear is a Ford 9". I will do a chassis dyno tuning session once I get the car back together. Unfortunately I will be choking the engine a bit with a set of 1 7/8" headers, but that's about as much as I can fit unfortunately. I do run true 3" dual exhaust to the rear of the car. The shaker also somewhat limits the amount of air I can pull in, although with the previous setup, I didn't see any real difference with or without the shaker installed.

I find it fun and interesting to compare my combination to others running the same heads and similar cams. My choice to run the single-plane intake definitely changes the characteristics of the powerband. When I run autocross or track days at COTA, I spend a lot of time above 5000 rpm. But I also street drive this car to/from events as far away as Dallas so far (~3.5 hours). It will take some tuning to get this combination road ready, but that is part of the fun of building these cars. :)

Nice Bryan with good testing comparisons and results. I'd think the Super Vic 4500 with Tony's porting would add up to be ruffly closer to the Mast. 4500 does add more Hp. Again nice results!

the only downside is that motor would run cost wise about the same as a 60,000 mile c6z. hmmm decisions decisions......

I agree... When I bought the GMPP and the Super Victor 4150, I also had a 4500 Super Victor on order to ship to Tony. It was backordered longer so I cancelled it. But the reality is that no one makes a 4500 TB which is short enough for me to fit my shaker. The Accel TB which I have is the shortest I've ever found (except the Scorpion which is no longer available) at 1 9/16". All of the 4500 TB are 2" or taller (with the 2" version not having an IAC which is a no go for me). I know it sounds crazy, but I'm really pushing my luck already with the Accel, I just can't go taller at this point.

I'm not complaining about my combination, it will make plenty of power for my needs, but I know there is more available if I were to ever try to step it up.

WRONG! I have the Accufab 4500 that flows 2128 CFM with (TPS and IAC). It measures 1 and 15/16. We as Texas brethren don't leave Nothing on the table. I would say you could send it back but you've had to do the fuel rails to make it work. I sent back a Vic Jr. a yr and half after purchase for the Super Vic along time ago.

https://accufabracing.com/throttle-b...-throttle-body

Bryan this is awesome! Have you contacted Tony yet? I don’t think he will be surprised, but I think your the first to try his LS7 heads and a single plane. Crazy how it holds flat up top...That car is gonna be a rocket!

Well that is interesting... When I spoke to them, I am certain they told me their 4500 TB was taller than that. You are measure from the bottom of the surface where it sits on the intake to the lip where the air cleaner sits, correct?

The 4500-2 TB which they sell that does not have the IAC is 2". I will have to call them again. The last thing I really need to do is to make a change at this point... :bash:

I have. As you would imagine, he's pretty busy, but he said he would take a look and chime in soon. I do think I'm the first single-plane combination using his heads, that was something we discussed way back when we started this project.

I'll be relying on the rev limiter a lot more now than I was before! :-)

Looking good! You are gonna love it.

Yeap I measured from the bottom to the top brother. And the - #2 4500 doesn't come with IAC but the one I posted does a small difference in cost. $50 difference. $599 vs $649

This IS not the # 2 4500
https://accufabracing.com/throttle-b...-throttle-body

This is the #2 without IAC
https://accufabracing.com/throttle-b...-throttle-body

I'm thinking I may sell my 5.3 block after confirming what me and Darth already figured out. Was even higher than him or I thought. So no need to build bigger I'm thinking. Little engine with a big stick for cam.

Again great build!

Bryan,
The engine and car are sick!!!

Bryan,
Congrats on outstanding results and progress!
Dan

Thanx guys!

Killer numbers! That is what I would expect from that combo and for only 12:1 compression that is great.

I have a 441 (4.190" bore/4" stroke), AllPro LS7 heads/single plane/intake/AccuFab4500, 13:1 compression with Jesel everything, Cammotion solid 252/260 .714" road race cam I just need to find a car for ;) Sold my LS7 RX-7. I'm hoping for similar power 750hp+ from it.

Too bad you sold the RX7. I always liked those cars, I just don't fit in them well. ;)

It will be really interesting to compare your build to mine. You will have more intake capability with the 4500 than my 4150, a bit more compression (13:1 vs. my 11.9:1), and a few more CI all with a similar cam.

I'm working to get the engine ready to drop back into the car. I spent the last 2 days getting the bellhousing aligned. That's now done, so next step is back into the car...

That'd be a great engine for my '95 Impala.

I'll come by next weekend and you can drop it in. :)

KW

Did you do any mods to the T56 Magnum? Meaning oil pump on the gears etc?

What oiling system are you running?

I'm running LS7 crank and Ti rods in my setup with lightweight RaceTec road race pistons. I feel for staying n/a that is all I would need.

95 SS impala was a badass car in its day. Had a friend who had one and he loved it like a son

No mods to the T56. I have considered a pump / cooler, but so far it's tolerated my autocross and track day activities. I don't do any road course sessions longer than 25 minutes, so perhaps that is why. Similarly, I haven't done anything to the differential gears yet either. I will only do that if I start running into problems.

I run a Dailey 3-stage dry sump pan and pump. I use a C&R radiator with water-to-oil cooling and a custom made oil tank (3.2G total tank capacity, I run about 12 quarts of oil in the whole system).

You will certainly have a lighter weight rotating assembly than I do. What flywheel / clutch will you run? I have a Monster LT1-S which I'm really happy with. I didn't go for the lightened flywheel option. I discussed it with them, but for the street driving I do and the fact that I do still care about having a reasonable idle, it wasn't worth the small improvement it might offer...