96" with SE MCR heads

[DoubleZ]

Ok so I've asked about doing a 96"w/ heads and cams before and was advised I'd be better off doing 107 and stock heads.   But I found a set of brand new SE mcr heads for a great price and decided I think it would be cool to build a bitchen 96" so that's what I'm doing.

Got questions on what cams would be best.  Seems like most say these heads are 78cc. According to big boyz that puts a 96" at 10.3 compression. I'd like to use S&S 585   Open to there's though if that's a bad choice. Maybe redshift 577 or fueling 574?  I'm looking for mid to upper rpm range cams. 

Harley makes it seem like these heads are a strait bolt on so I assume valve to piston clearance won't be an issue.  Anybody have any real world experience with that?

Also heads are machines for releases.  Do I have to use the Harley ones? Or will s&s ones work the same?

Thanks

[baker]

The SE MCR heads you are talking about have a 76cc chamber, they were discontinued after 2011 and sold for $950 new, if you can get a new set cheap I'd jump on it. Be careful of the TDC lift on your cam choice with those heads, the higher TDC and longer overlap of the redshift cam would make me measure valve to valve clearence and valve pocket clearence if I were using those heads.

[DoubleZ]

The SE MCR heads you are talking about have a 76cc chamber, they were discontinued after 2011 and sold for $950 new, if you can get a new set cheap I'd jump on it. Be careful of the TDC lift on your cam choice with those heads, the higher TDC and longer overlap of the redshift cam would make me measure valve to valve clearence and valve pocket clearence if I were using those heads.

Thanks I already found a set way cheaper than that and pulled the trigger the other day. 
I hear what ur saying about the TDC lift but really don't know how much is too much.  Is there some range I should be looking for?

[redmtrckl]

Moco has piston set specifically made for those heads, correct dome shape and valve reliefs.

[DoubleZ]

Moco has piston set specifically made for those heads, correct dome shape and valve reliefs.

I think your thinking of the 103 pistons.  im looking at the 2011 SE catalog now and there is no aftermarket piston for stock bore listed.   although it does specifically state that those heads on a 96" makes 10.3 compression with original equipment pistons.  which is why i feel these should be safe to bolt on a stock 96"

[redmtrckl]

Right, they are for 103 bore. Also you will probably need to clearance the rocker boxes for those valve springs since they are not beehive springs. Stock pistons will have to be flycut for those big 2.12 intakes.

[DoubleZ]

Right, they are for 103 bore.  :chop:Also you will probably need to clearance the rocker boxes for those valve springs since they are not beehive springs. Stock pistons will have to be flycut for those big 2.12 intakes.

SE MCR head have 1.9 intake and 1.62 exhaust.  Heads are milled .060 form stock.   Info stolen from a post by wfolarry on another forum. 
Thanks for the info on the rocker boxes.  Was curious if I'd have to do that

[redmtrckl]

I was thinking of the MVA heads. I have used the old SE heads with the 1.9 intakes and had to increase the valve reliefs for SE251 cams. Anything over .510 lift would be suspect with the stock pistons. Clay it up to be sure.
My old 95" with those heads made 112hp with Wild Things tc4 cams and a Fatcat and 45 Mikuni. I used them on a 107 and got 110/122 with just a bit of clean up in the ports and valve job, same exhaust and carb. 

[DoubleZ]

ok so im going to use a .040 headgasket, which should put me at about 10.1 and run a ss570 cam.   im hoping with this i shouldnt run into any valve to piston clearance issues.   

where do i get s&s non-ez start cams?    all i can find are ez starts.  these heads are drilled for releases so i dont need both.

[Admiral Akbar]

I have a set.. PM me.. 07 up- non easy start..

Max

[Pilgrim]

This post may be accused of  pollution from a previous thread of mine dealing with work on MCR heads, but here goes . . .

To those who remember the previous s**tstorm over my post back in Dec: the guy has fixed a faulty flow bench. You were all correct; the numbers were bad.

After repair of the flow bench my MCR heads, out of the box, showed that at low to medium lift, from about .250 to .400, they flowed about 7 CFM less than a stock 96" head. At .600 (which more lift than my SE 259 cam has) they only flowed about 10% better than the OEM 96" head.

In the process of working the MCRs over the heads were found to have a substantial core shift in the intake port.

Pilgrim

. 

[Clayster]

FWIW, I've read 'on the Internet' that the MCR heads are simply stock heads that were decked to raise compression and have manual compression releases (MCR) added. 

[bigpete1]

FWIW, I've read 'on the Internet' that the MCR heads are simply stock heads that were decked to raise compression and have manual compression releases (MCR) added.

you are incorrect on this .the compressor heads are what you are thinking of with your post .thanks pete

[DoubleZ]

Would there be any real benefit to having my throttle body bored out with this build?   I'm not sure if its really necessary but if its good for maybe another 5 hp/tq I might look into it.

[redmtrckl]

Would there be any real benefit to having my throttle body bored out with this build?   I'm not sure if its really necessary but if its good for maybe another 5 hp/tq I might look into it.

Maybe, but for air flow comparison a 45mm Mik. carb will give a 107 all it needs. TB is a different animal I know as it is not dependent on map signal to get the gas jets flowing. Would probably help HP until the heads quit flowing.