New Motor Build

[NEILZVETTE]

The MMR motor started to smoke some. Hoped it was just a bad turbo seal...nope. Motor is out and hope to get away with just a re-ring but expect the pistons may need replacing maybe as this car had seen 20lbs often over the last 20K miles. It was down on compresion on a few of the cylinders but ran good otherwise. For background MMR 8.5comp 4.6, On3 Masterpower 70mm @ 15lbs , no cats straight pipes. 3.55 gears with 5 speed.It also has 80lb injectors and GT500 fuel pumps. It looks like the stock intake has had the butterflies removed.

Plan is Stainless Rings this time, bump compression up to 9 to1 and port heads. Any other suggestions? Thinking XE253 cams springs, mild port work and Ford Racing Intake? I'm all ears guys I have played with LS motors but this is my first mod motor! Also have a line on some XE 253 cams..thoughts?

 

[4.6fan]

how much power were you making with that setup?

 

[ford20]

Who will be rebuilding the motor?

 

[BruceH]

The MMR motor started to smoke some. Hoped it was just a bad turbo seal...nope. Motor is out and hope to get away with just a re-ring but expect the pistons may need replacing maybe as this car had seen 20lbs often over the last 20K miles. It was down on compresion on a few of the cylinders but ran good otherwise. For background MMR 8.5comp 4.6, On3 Masterpower 70mm @ 15lbs , no cats straight pipes. 3.55 gears with 5 speed.It also has 80lb injectors and GT500 fuel pumps. It looks like the stock intake has had the butterflies removed.

Plan is Stainless Rings this time, bump compression up to 9 to1 and port heads. Any other suggestions? Thinking XE253 cams springs, mild port work and Ford Racing Intake? I'm all ears guys I have played with LS motors but this is my first mod motor! Also have a line on some XE 253 cams..thoughts?

I take it you bought this already modified? What is the part number to the cams you are looking at, 127xxx?

There is a vendor for comp turbos on this site, it might be time to put a billet wheel turbo on as long as everything is apart.

 

[JoshK]

I have a set of 9.5:1 custom pistons for sale.

 

[NEILZVETTE]

Yea the MMR 800 that KrisR installed lasted 20k miles. Still ran well just would smoke from time to time. I think it put down low 600hp and around 700tq at 20lbs on E85 at one time. I was running 93 octane and 15lbs while I had it. I would have guessed about 550hp at that point. It wasn't being babied shit just happens in boosted applications. Popped a ring on a turbo LS1 Vette a couple of years ago too.Figure a couple of rings got smoked as a few cylinders were low on compression. I was very happy with the power on stock cams as it spooled very quickly. But with a .68 housing it choked it off on top end. Figure if I can score some used cams that will work well with turbo may pick them up also. Considered uping compression ratio some so I would not need to run the turbo so hard or just getting a bigger a/r housing.
I'm in central Illinois so not a lot of Mod Motor shops here. Going to have a local shop do the work,I am getting too old to crawl around cars anymore. Hoping the MMR supplied block is still standard bore and that the h beams and such are ok. Anyone have thoughts on stainless rings or Hellfire?

 

[NEILZVETTE]

Seems that they are getting greatnumbers out of higher compression Coyotee/Boss motors with turbos?

 

[warpig12354]

Seems that they are getting greatnumbers out of higher compression Coyotee/Boss motors with turbos?

Yes.

 

[NEILZVETTE]

Thoughts on Compresiion Ratio and Hellfire rings vs Modmax Stainless rings. Would rather not have to do this process again anytime soon?

 

[retfr8flyr]

I just rebuilt mine with Manley -6.5cc dish pistons and Hellfire rings. I'm waiting to see how it does but my builder highly recommended the Hellfire rings and I wanted to go back to higher compression. These mod motors love compression, my old combination with -17cc dish pistons was very doggy when not in boost.


Earl

 

[Saleen S281]

Any updates?

 

[NEILZVETTE]

Not, yet engine has been at the shop for about a month now and hoping to get an update soon. It has a Spec +2 in it now with 15K miles on it a planned on replacing the disc as we have it apart. Anyone have a suggestion as to putting the 3+ in or maybe a disc from another manufacture, I was not impressed with 1-2 shifts with the +2 although my understanding is these cars have a lot of twist in the driveline and it's common under hard acceleration. It has aftermarket motor mounts and thought of going to solid motor mount as that helped in big block Camaro I had once.

 

[tjm73]

Yea the MMR 800 that KrisR installed lasted 20k miles.

I'd be pretty pissed if I bought a "built" motor and it only lasted 20K.

 

[Juiced 66]

^^ me too

 

[Scuba-Matt]

OK I'll say it, MMR sucks.

 

[NEILZVETTE]

Ok it's not going back to MMR.

 

[rcm90]

What compression did you end up with and what rings did you use?

 

[GT E UPP]

Not, yet engine has been at the shop for about a month now and hoping to get an update soon. It has a Spec +2 in it now with 15K miles on it a planned on replacing the disc as we have it apart. Anyone have a suggestion as to putting the 3+ in or maybe a disc from another manufacture, I was not impressed with 1-2 shifts with the +2 although my understanding is these cars have a lot of twist in the driveline and it's common under hard acceleration. It has aftermarket motor mounts and thought of going to solid motor mount as that helped in big block Camaro I had once.

You may want to consider a Spec Super Twin Disk clutch with the aluminun flywheel. This one has treated me very well...

 

[NEILZVETTE]

Update-Machine shop opened it up today and found ALL of the ring lands on passenger bank were broken. They didn't mention condition of the cylinder walls yet! Suggestions on pistons and compression ratio this time?