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Just thought I would share the build results of one of my customers (Jack Turpin).
It was basically a 416 shortblock which I sent him in a crate.....he installed the cam and built the rest of the engine with parts that I spec'ed and provided for him of course.
The typical cast of characters for a Mamo Motorsports stroker recipe are in play here
MMS 235 heads (not the NFI version)
MMS Pro 10mm Ultralite rocker arms
Johnson short travel lifters with axle oiling
Ported FAST 102 intake and NW 102 ETC TB (C5 application)
Custom MMS spec'ed cam (fairly aggressive 247 / 252 on a 113 LSA)
11.75 CR (93 octane build)
Drum-roll for final results!!
Reeeally flat power and TQ curve.....makes over 550 RWHP from 5800 - 6700 RPM.....that's very impressive for mid sized stroker with a medium sized cylinder head. Jack says its insane to drive.....it will actually break the tires loose in 3rd after its hooked as the engine gets into its sweet spot.....like a turbo coming in.
Honest dyno.....this is the same car/customer that I helped a couple of years ago with a max effort stock displacement build (346 CID in a 99' C5) and Mamofied AFR 215's at the time (my new MMS heads weren't out yet of course).
With an electric WP, Mamofied lightweight RPS clutch and all the trimmings (only a 227/231 cam), the car put down 487/419 TQ....in fact knowing how stingy this dyno was on TQ I was really pleased it cleared 500 RWTQ with the new combo
His 346 was pretty sexy also....same car....same dyno....same tuner
A complete write-up on both builds can be found here....the new 416 build is in the back of this thread
Keep in mind guys.....I didn't personally build this engine. I sent him an assembled shortblock in a crate (race prepped block with a balanced rotating assy fitted and installed in it) and all the rest of the parts were sent separately (cam, heads, valvetrain bits, induction etc.). Jack handled the build himself with the help of a former GM mechanic close by and had a local shop handle the tune when the car was ready (JHR Performance).
Wish I was closer.....would love to drive it! (Jack is still afraid to really give it all the reigns!!).....maybe now with slightly warmer tarmac temps it will hook a little more!
Cheers,
Tony
PS.....Forgot to mention this combo only has 1.75 headers....clearly too small for optimal results. With a larger header the power curve would have been even loftier. I bet a 1.875 header would have been worth 8-10 on this engine easily. Hell I saw a gain of 8 RWHP on my former 383 and that motor didn't have a head nearly as good as my new MMS 235.....the head on Jacks car is 20 CFM better than the head I ran on my 83'
Thanks for the write up Tony! The car is a blast to drive....power and torque to spare. Coming home from the tune doing 70-75mph interstate driving the car averaged 24mpg too. No blower, no nitrous just some Mamo massaged Chevy LS horsepower. Hard to beat.
Hmmmm.....guess you haven't followed many of the MMS cylinder head threads. Let me clarify....they are AFR castings that were digitized with my latest and greatest port designs.....they have custom seat work and unique cuts on the valves etc. You can look at them as an AFR V3 (after all, I designed the V1 and the V2) or an MMS V1.....same thing.....LOL. Basically my new MMS cathedral heads all start life as a 190 cc AFR porter's casting to directly answer you question I guess.
Originally Posted by Rise of the Phoenix
Do you think the TSP 2" headers would be too much for this build?
Not sure....really depends on alot of other factors concerning the actual header and collector design, primary tube length etc. Assuming the fit and finish and design is good I would imagine it would be worth some power on a build like this....its basically a 650 (or close) HP engine at the flywheel.....your getting into 2" header territory but you might give up more on the bottom than you get upstairs....that would be my only concern.
Originally Posted by Zmg00camaross
Nice results! What's a $ amount to build that girl?
You know what they say......if you have to ask
While I wouldn't call this "girl" a supermodel, my guess is if you don't spend four digits on her at Xmas time, that well might dry up if you get my meaning....LOL
Seriously though, lets not make any bones about the fact its an optimized build with the right components....a long way from a budget build but no money was wasted. All the power and TQ Jack paid for is there, but you don't fall on these type of results slamming some parts together and cutting a few corners....not even with respected name brand parts. You have to have a really good combination.....its not just about spending money
I know all to well on the means. I just have a 6.2 I am getting ready to disassembly and just researching. I am more drag track orentated. No doubt nice results, just looking at your heads or some TFS. But seen similar power out of 364 ci. But of course apples to oranges because of port, compression, fuel etc.
I know all to well on the means. I just have a 6.2 I am getting ready to disassembly and just researching. I am more drag track orentated. No doubt nice results, just looking at your heads or some TFS. But seen similar power out of 364 ci. But of course apples to oranges because of port, compression, fuel etc.
I would like to see that 364 dyno actually.....I have been following Tech for a decade+ and even low 400 CID engines reaching 550 RWHP are not easy to come by assuming we are talking the typical pump gas HR, FAST 102 type of set-up that produces a really broad power and torque curve (aka a really good street engine).
And there is no way a smaller engine would pull down these types of torque numbers also.....not to mention we all know the dyno itself is the largest variable of all when comparing data. Knowing this number came from the same car and dyno that a really stout 346 only managed 419 RWTQ and still carried well enough to punch 487 HP tells me this dyno is accurate if not a bit on the stingy side. Most of my better 346 combos make 425-430 RWTQ at the same power. Hell my 346 made 435 RWTQ a decade ago but less power (475 ish) with less head and a slightly smaller cam.
Point is Im confident the dyno Jack rolled on isnt giving away numbers....its hard to compare engine combinations with any sort of accuracy unless your testing on the same equipment but regardless, this is a hard running LS3 bore based combo.....no question about it and the 15K someone previously posted is right in the ballpark if your tackling the build yourself with the parts I would provide. Sounds like alot of money till you actually crunch the numbers to build a complete stroker engine on paper....its more than most people realize with the exception of those that have built one already or really carefully examined the costs involved to build one right with the better parts that produce more power and offer higher levels of reliability.
Lets face it, if it were relatively inexpensive, everyone would have one parked under their hood!
I was thinking 15k, the engine I was talking about is LS3 370. And was on a engine dyno single plane high compression deal. Like sayed it's not apples to oranges. Just in the process of researching for my build that's it all.
Jack
What size is your exhaust after the headers?
I am betting 2 1/2"
Reson I ask is because I have a 99 C5 also, with a
Mamo Top-End build in process as well. Nick @ ARH
Told me that 2 1/2" exhaust would reduce HP by
at least 20-30 @ 650+ FWHP compared to a full 3"" Exhaust
at the cost of increased noise as well.
Not that you need any more power LOL, just curious.
Congrats Again on your results!
Jack
What size is your exhaust after the headers?
I am betting 2 1/2"
Reson I ask is because I have a 99 C5 also, with a
Mamo Top-End build in process as well. Nick @ ARH
Told me that 2 1/2" exhaust would reduce HP by
at least 20-30 @ 650+ FWHP compared to a full 3"" Exhaust
at the cost of increased noise as well.
Not that you need any more power LOL, just curious.
Congrats Again on your results!
Navy, others....
Jack texted me to let me know its actually a 1.875 header in his C5 now (and naturally a 3" main system). I didn't realize Jack had purchased larger headers during the course of the build after the 346 came out of the car.
I think 1 .875 with an "X" pipe and 3" main (necking down to 2.5 as it approaches the catback) is actually the ideal all around size system for this size engine at this power level. While a 2" might be worth a few up top I think it would hurt the TQ under 4500.
Just wanted to clarify for everyone what Jack is running
Will he be taking it to the track? Would like to see trap speeds. Should be awesome due to the 5th generation corvette being so light. Saw a lot of stock ZO6s being around 3030 lbs.
Will he be taking it to the track? Would like to see trap speeds. Should be awesome due to the 5th generation corvette being so light. Saw a lot of stock ZO6s being around 3030 lbs.
Im not sure.....he really needs a dedicated drag set-up if he did or it would be a useless endeavor anyway. Im pretty sure he has plans to but likely has to get a few things handled before he attempts it.
I'm not sure if its a Z06 btw.....it may be just a conventional C5 but either way this kind of power even in a 3400 lb car is a ton of fun!
I'm sure Jack will chime in at some point with his plans to hit the local strip or not.....he has the right driveline.....just needs serious rubber (ET Streets or Hoosiers etc.) to be able to put all the torque to the ground right out of the hole.
02-25-2016, 03:19 AM
416 LS3 Stroker with MMS 235 cathedral results! 
15k 
