MMS LS7 heads ERL 427 swapping to HPR 468
 

<<< Updated …. swapping to a HPR 468 short block see below

Working with Tony Mamo for my last set of ported heads (AFR 205s) turned out well both on the dyno and strip so going back for his current offering really wasn't a difficult decision to make. The goal is 550 - 600 rwhp NA

For his LS7 offering, Tony starts with Trick Flow Specialties 260cc square port cylinder heads for the LS7. Once his magic is worked the heads are reborn as Mamo Motorsports (MMS) 265cc LS7 heads with the following flow numbers.


Lift Intake Exhaust
.200 160 123
.300 232 181
.400 300 226
.500 351 247
.600 387 260
.650 396 265
.700 404 268
.750 410 271

Tony combines his heads with a well thought out package to optimize and compliment them.

Assembled MMS ported 265CC ls7 Cylinder Heads milled to 61cc
PAC 650 springs and Ti retainers
Hollow valve upgrade
Manton custom length Pushrods ( 3/8 x .095 wall)
Yella Terra MMS LS7 Ultralight Shaft rockers 1.85 ratio (These are custom made for Tony by Yella Terra)
234/248 .601 .606 116+4 Custom Cam (234/248 .637 .643 116+4 at 1.85 rocker ratio)
MMS ported LSA oil pump
Johnson .058 limited travel lifters with AOL (Axel wheel dedicated oiling)
MSD Atomic Airforce Intake Manifold for LS7 103 mm (also ported by Tony)


In addition to this, so far, I'm adding the following:

Holley EFI Billet 105mm LS Throttle Body W/Low RPM Taper and Cable Drive
JP Performance Upper Sprocket ... to tighten up the timing chain
LS7 GM fuel rails
ATI Super Damper Harmonic Series Harmonic Balancer, 10% underdrive
... probably more once we get to the fuel system


The rest of the build include the following items already on the car

ERL Performance 427 LS2 Dry-Sleeve Short Block

• Wiseco Professional Series Pistons (K446x125) and rings
• Compstar crankshaft and rods
• ACL main and rod bearings
• Clevite cam bearings

Kooks 1 7/8 Headers with Calico Coatings + catted midpipes
Kooks Street Screamer Dual exit 3 inch catback
Svede OTRCAI
Lingenfelter High Flow fuel Pump
Braided Fuel Lines
ARP Harmonic Balancer Bolt
Katech Belt tensioner
MSD LS1 Blaster Coils
Racetronic 42 lb flow matched injectors
Moroso Ultra 40 Race Ignition Wires
AMW Catch Can
Moroso Catch Can
Meziere Electric Water Pump
Mishimoto Radiator and Hoses
160 Degree Thermostat
Mocal 19 row Oil Cooler Fan Combo
Improved Racing cooler adapter
Improved Racing thermostat
Aeroquip -6AN Fittings
Easton Aeroquip Starlite Racing hose
Auto-meter Oil Temperature and Oil Pressure gauges
Steel Braided Transmission Lines
Rossler Terminator III Transmission with additional upgraded billet parts
Precision Industries Vigilante Converter (3600 triple disk)
Derale Atomic Cool Transmission Cooler Fan Combo
Quick Time RM-9034 Bellhousing
Meziere Billet flexplate
Drive Shaft Shop Carbon Fiber Driveshaft
Drive Shaft Shop 1000 rwhp stub to hub axles
BMR Drive Shaft Loop
Diff Technics 3.73 gears
Harrop Diff cover
Optima Red Top Battery
Baer Front 13 inch Big Brake System
Baer Rear 13 inch Big Brake System
Porterfield Brake Pads


Now as to where we currently are with the build:

• the heads are on,
• cam has been degreed in,
• oil pump and timing set installed,
• Rockers on and adjusted
• Valve covers back on

A couple more things...

The head gasket used is a Cometic .036 on a 4.160 bore, that with the heads milled to 61cc plus the existing 18 CCR pistons will give me around a 11:1 CR

Tony was given the zero lash figures for all 16 valves to order the custom length Manton push rods.

If all goes according to plan we should tune and dyno sometime next month.

Great parts selection! Is this going into a GTO?
What are Design/Performance Goals?
I like the Conservative Cam Specs, should drive
Very well on the street.
(Are the lift #s calculated with 1.85 RR Ratio?)

You will be closer to 600 than 550.

Yes my 2004 GTO
I've run 10.95 with the AFR 205s on the 427 block so my goal is to break the best GTO FL NA time listed on LS1GTO.com which is I think a 10.5x. But of course the deeper I can get into the10s the better lol
No that's not factoring in the 1.85 ratio into the cam specs ... it's 234/248 .637 .643 116+4 with that

I like what your doing here, as I am wrapping up a 434” Mamo build right now with his ls7 heads. I have to ask however, why the piston choice? Were you doing forced induction before, or planning to do so in the future?
My heads are cut to 62cc and with my -8 cc pistons, I’m at 12.42:1
I’m gonna start a build thread soon...

Frankly I didn't know that ERL had put those in. I ordered a NA motor from them. Now I know why I fell short of the 500 rwhp mark I was shooting for. ... and we know why they are out of business.

Should be a killer set-up!

I'm gonna state the obvious.....you'll hit your HP goals. :burn:

Looking forward to seeing results!

KW

Look forward to seeing this. Nice.

What did it dyno before? Should be very interesting to see before and after results.

In my sig ...

490.16 rwhp 479.01 rwtq

That's a really mild cam

Yes....., Yes it is.

Well it's what Tony dialed up. We'll see the results and take it from there if need be. The cam with my 205's was a FlowTech Induction MAX-AIR 16 V3 HR16 +3 custom cam by Ed Curtis 231 235 .651 .651

Wow...Tony usually goes all out with camshaft numbers. I had to pull back on him some, because mine is a driver only, and I’m still WAY more camshaft than you have here. I’ve had conversations with other customers of Tony’s, and they all say the same thing...of course I’m talking with guys going solid roller.
Nothing wrong with what your doing here at all! Can’t wait to see numbers!

Your Cam will be fine.

BigHammer went giant,from ~22* Overlap to almost 32* Overlap
In his existing 388" Combo.
That will be an interesting comparison to his current results,
Especially streetability, Huge Tuning Challenge IMO.

Sounds like Tony M knows where to go easy on the cam when need be.. but that's why he is who he is....

Since almost everyone goes to a Nick William 102mm TB with these heads I decided to throw my tuner a little curve ball and go with the Holley EFI Billet 105mm LS Throttle Body W/Low RPM Taper. He said he wasn't scared with seeing what the 105 would do. lol The tuner is Erik Johnson at Back Street Performance in Medina, Ohio. Back Street has always done all the work on this car for me plus they have experience with Tony's LS7 heads from other builds.

I figure the 105 and 95 Holley are that size to make up for the taper. Basically they flow the same as the straight 102 and 92. I don't like the weaker spring on the hard idle, so I ordered stiffer ones from McMaster. Also don't have any luck with the plastic plunger IAC.

Erik is the man.