MRL 416 w/Big Mouth heads

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MRL Performance

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So there has been some talk about these heads. These are the First ones I have used. The reason was to get as much air flow and port volume for what we wanted to do. The goal was to make as much power as early as possible. I think we got what we wanted, but without a back to back test its hard to tell if these heads were worth it or not.

Anyhow, here is the combo
360 stroked and poked to 416
Flat top pistons 10.8 to 1
BM heads
MRL/BAM offset roller lifters
RPM dual plane intake
FiTech EFI
MRL solid roller cam 281/285 duration(seat to seat) .620 lift
Milodon gear drive
Well, you get the idea. Torque is what we wanted. Did we get some? Ummm........... Yeah we did.

525tq at 3100rpm, yes 3100rpm. Damn. Peaked with 582tq at 4350rpm. Still making 550tq at 5500rpm.
It also made 584HP at 5800rpm. Fuel pressure was dropping as I had the pump hooked up wrong, didnt figure it out until later. Might make closer to 600hp with the right fuel pressure.

All this on pump gas, and a nice idle. It pulled 14in vacuum at 950rpm idle. 1.40 hp per ci, not to bad for a Pump gas street engine.

View attachment 1715028325

View attachment 1715028326

2017-03-13 12.29.34.png


1848.jpeg
 
What were the final flow numbers on those heads ? Valve size ? 1.6 or 1.5 rockers ? Etc....
 
While the numbers are very impressive, I'm even more impressed with the RPM's. 1.4 and peaking before 6K is quite an accomplishment. Normally an engine making 1.4 @ 6K is on it's way to 2.0 at 8k.
 
mbaird said:
What were the final flow numbers on those heads ? Valve size ? 1.6 or 1.5 rockers ? Etc....
Click to expand...
I did throw them on the bench to see what they were. Just a down and dirty flow, didnt write anything down. I know it was not off by a bunch or I would have sent them back. It was within 5% of claimed, so i didnt worry about it.
Valves were 2.08/1.60 rockers were 1.6

Im happy with what we got. This thing was cranking out a LOT of torque and holding it forever, 500tq+ at 6000rpm is a lot!
 
dynodonn said:
How much would you want for an engine like this?
Click to expand...

Not 100% sure, it was a re-do of an already existing engine. We changed the oil pan, heads, rockers, cam, lifters, pushrods and added a gear drive. It wasnt cheap, high $$ stuff. Im going to guess all done from scratch, the same way $13k+
 
I asked for 2 reasons...
1.) I got confused and thought this was a continuation of the 360 Bigmouth thread...lol
2.) Its very similar to my current build except Im using W2s and a M1 dual plane. Results are exactly what Im looking for. But Im sure you wont divulge your grind even if I use your offset lifters...lol
I will also be running a carb for now but if that EFI makes all the difference that could change..
 
That some nice numbers Mike, that torque is going to be a beast on the streets!!!

look forward to doing a build with you in the future! thanks for answering some of my questions today........... keep pumping these monsters out!!!
 
MRL Performance said:
Not 100% sure, it was a re-do of an already existing engine. We changed the oil pan, heads, rockers, cam, lifters, pushrods and added a gear drive. It wasnt cheap, high $$ stuff. Im going to guess all done from scratch, the same way $13k+
Click to expand...

$13k--------Easy. J.Rob
 
MRL Performance said:
So there has been some talk about these heads. These are the First ones I have used. The reason was to get as much air flow and port volume for what we wanted to do. The goal was to make as much power as early as possible. I think we got what we wanted, but without a back to back test its hard to tell if these heads were worth it or not.

Anyhow, here is the combo
360 stroked and poked to 416
Flat top pistons 10.8 to 1
BM heads
MRL/BAM offset roller lifters
RPM dual plane intake
FiTech EFI
MRL solid roller cam 281/285 duration(seat to seat) .620 lift
Milodon gear drive
Well, you get the idea. Torque is what we wanted. Did we get some? Ummm........... Yeah we did.

525tq at 3100rpm, yes 3100rpm. Damn. Peaked with 582tq at 4350rpm. Still making 550tq at 5500rpm.
It also made 584HP at 5800rpm. Fuel pressure was dropping as I had the pump hooked up wrong, didnt figure it out until later. Might make closer to 600hp with the right fuel pressure.

All this on pump gas, and a nice idle. It pulled 14in vacuum at 950rpm idle. 1.40 hp per ci, not to bad for a Pump gas street engine.

]
Click to expand...

Mike, What did you think of the S.S.? Did you blend the horrendous bump where the CNC transitions from the intake flange side to the valve side?

14" vacuum with this kind of power and you call this nice? I call it freakin AMAZING!

Seriously , you could have beat Kaase's 415 Cleveland @ 2015 EMC with this and pocketed an additional 12g's . Unbelievable job! J.Rob
 
This would make a dynomite street brawler, torque plus a hundred less pounds on the front (not to mention being able to run a 904),which is priceless on unprepped pavement. It could embarrass a few bigblock combos I am sure!
 
RAMM said:
Mike, What did you think of the S.S.? Did you blend the horrendous bump where the CNC transitions from the intake flange side to the valve side?

14" vacuum with this kind of power and you call this nice? I call it freakin AMAZING!

Seriously , you could have beat Kaase's 415 Cleveland @ 2015 EMC with this and pocketed an additional 12g's . Unbelievable job! J.Rob
Click to expand...

SS was a bit ... flat i guess you would call it. Yes those bumps are in every set of CNC heads I have ever dellt with. They were cleaned up before assembly and install, same on the exhaust side.

Here is a pic of the "BUMP" from another set I did a while back. Fixing this build(from another shop) and bad cam install was worth 50hp.

P1100449.JPG
 
MRL Performance said:
SS was a bit ... flat i guess you would call it. Yes those bumps are in every set of CNC heads I have ever dellt with. They were cleaned up before assembly and install, same on the exhaust side.

Here is a pic of the "BUMP" from another set I did a while back. Fixing this build(from another shop) and bad cam install was worth 50hp.

View attachment 1715028526
Click to expand...

Maybe there's hope for these heads after all. I will find out for myself soon-Crossed fingers. Thanks Mike, J.Rob
 
Stout! That thing makes great power. I am really impressed with the 14" of vacuum at 950. More than enough to run power everything on a typical street car.

I'm curious if you'd be willing to give out more cam specs? And with your solid roller lifters do you still need to make the mods to the block (blocking passenger side oil galley, driver side plug, etc)? I know this used to be a thing a few years ago. Not sure if updated lifter designs have fixed these problems. I'm looking at going solid roller myself. Probably something very similar to what you have in this.
 
Short video. At the angle I had the camera it looks like 13in on the gauge, but when looking at it straight on, it was right on 14in. At a 2500rpm road load, it was pulling around 22in.

 
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