outhouse

Mamo goes into the value of porting these heads for stock engines and his opinion is night and day different to matts, I trust Mamo who also has backed up his test with dyno runs.



Matt does not have the experience with this manifold, if that is his suggestion. He is leaving half the gains on the table by your numbers alone.


My experience is not unique and its not just the collective knowledge from other users.


While they will not back out, under heat and compression from the manifold to head bolts the clamshell allen bolts factually get loose enough to almost lose contact with the washer, meaning they will be very loose.


Every last one of mine which were tightened overtight took 2-4 revolutions more to get tight after breaking in for a few hours.


Even the manifold to head allen bolts get loose after a few days, then again after a few weeks.


This manifold requires attention after being bolted on. EVEN after retightening the manifold to head bolts 3 different times [2 hours, 2 days and then again after 2 weeks] after 8-10 weeks they were all VERY loose again and needed to be retightened.


Just telling you how it is with nothing to gain or loose here, just trying to help.


Do yourself a favor here if you have a few days run time in, go out and back out a clamshell bolt one turn to break it free from loktite, then see how many revolutions it turns back in, ill bet you lunch it is no where near tight at 1 revolution you loosened it.


Now the top and bottom 3 bolts in the middle are fine, its only the outer clamshell bolts and manifold to head bolts that get loose.

outhouse

Porting the MSD and a mild cam will be a decision you will never regret.


Mine is an outside daily driving car that drives 100% stock if not better then stock with a 100HP gain over stock, with what you have done you will be about 120 -140 with mild cam and porting with perfect street manners. Cam and tune dependent. Choice is critical here.


Matter of fact I used to get smell out of mine before the cam and mods when hitting 7k. Now never.

keeso6z

That sucks! Thanks for the input. I better check them.

outhouse

All I ask


And I hope I'm proven wrong here.


But don't get caught a few months later, After the 2 week tightening, I checked again 2 weeks later and they were tight so I drove it a few months and noticed a slight change in idle, and sure enough all the manifold to head bolts were all very loose again.


My guess is the manifold material contracts quite a bit with heat cycles leaving loose bolts.


One guy reported having to do his manifold to head bolts monthly.

Tech

"Completely ridiculous and absurd not to [port an MSD]." Made me think of this...

outhouse

Its not absurd or ridiculous, its just leaving some really easy free HP gains on the table for a few hours work.


The casting errors on these intakes vary greatly from one to another. So porting could literally double OP's HP gains.


Look at the pic I already posted showing how bad some of the casting can be, I had 4 ports that bad mismatched against the rest. No way I could run that without some dremel love. I spent over 4 hours on mine, and at least NOW they are all even.

MTPZ06

Cam Motion has a very mild "Stage 2" as well... http://store.cammotion.com/ls7-427ci

If I ever do a cam, it'll be a mild/baby cam from Kip at Cam Motion; but it may actually be a custom grind...unless he felt his stage 2 met my needs.

nuke61

I think there's no doubt that it's a must do if it's your own labor, but a question about whether it's worth it to pay someone else several hundred dollars to do it.

MTPZ06

Yes, but MSD is better than FAST pretty much everywhere on the LS7.

nosno

quoted from outhouse-
"Do yourself a favor here if you have a few days run time in, go out and back out a clamshell bolt one turn to break it free from loktite, then see how many revolutions it turns back in, ill bet you lunch it is no where near tight at 1 revolution you loosened it.


Now the top and bottom 3 bolts in the middle are fine, its only the outer clamshell bolts and manifold to head bolts that get loose"

Does anyone have a pic of the bolts that need to be checked? My car isn't by me so was just curious if these bolts are obvious or not, thanks

outhouse

The intake manifold has many short allen bolts that hold the two halves together, these are the clamshell bolts I speak of. They are the ones on the outside




Then you have 10 long allen bolts that actually hold the intake to the head. These are the ones towards the inside.

outhouse

Double the HP for what $300 from most vendors who will port?


He spent what 2k + after install, purchase, tune ?


Lets say the 102 gained him 8HP


That's means he spent 2k on intake install for 10hp as he only gained 18 total with the 102.


Many people are reporting 25-35 HP from a ported MSD, so TO ME adding a possible 15HP from porting makes sense. But YES I do everything myself when possible or intellectually advantages.

nuke61

I completely agree, and especially with not doing a cam too.

keeso6z

Outhouse, are you figures of 25-35rwhp on cammed cars? I believe they are. But it should make more power with a stock cam. Kind of bummed I didn't get it done, but I don't know how much it would have cost. They told me the same thing about the MSD and the intake - it wouldn't be worth it without a cam. I proved them wrong on that. John's statement was they were smoke and mirrors. After reading a lot on the Forum, that wasn't the case. There was one thread about a stock Camaro SS picking up 20rwhp with this combo.

outhouse

I believe Mamo has his dynod to a stock engine

outhouse

The gains are all over the board as Mamo states, this is due to the different amount of casting flaws.


Again I had 4 flaws similar to the pic I posted, imagine if you had 6 or more.


Real world you received 10 HP, this tells me you left that much on the table at minimum.


One guy reported over 40HP with a cam and the addition of a 102 like you 515 rwhp to 562 rwhp, I'm being conservative. Just so you know my tuner who is great and builds great motors claimed all the MSDs he did were right around 10 as well, but not one was ported. This was on cammed cars.

RamAir972003

To be honest nothing against mamo but the fast is just as good in mid range where the peak power on the msd is better....if Tony had a fast that he used to do as well I'm not seeing that much more in peak all around the msd is better but gaining 40hp with just an intake that means the heads are not doing there job or the tune was ****. Just cam alone in ls7 you get 40 50 wheel sometimes depends on day.
.either way Darrin Morgan is porting mine can't wait to see what I get....Or if Tony can start doing the Holley mid intake I would love to see those results....

nuke61

Baseline was 525 whp, so it's not stock, but not a high HP N/A car either. Same day, no change to the tune. +18 hp.

injfuel

Was this using the stock throttle body with both intakes ?

nuke61

I don't know, I just saw this on YouTube while looking at car videos.