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Dyno Results: MMS LS7 heads ERL 427 build has begun

 
Old 03-31-2019, 01:11 PM
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It's a bit unusual you spent all that money with your original build and produced a low torque figure. Usually these heads produce a ton of torque.
If you are aiming for a NA engine why use dish pistons?
You are better off with flat tops.
Cam choice was also very mild for such a size engine and so was compression.
You are leaving power on the table for no good reason.
I must admit though, that flat torque curve is amazing with hardly any drop off even near the red line.
This is one benefit of wide split cams too. They do wonders for power and torque after peak.
Cam Specs are ok but you need more IVC timing and overlap.
IVC needs to be at 52 and maybe open the exhaust a little earlier at 65 or 66
So something like a 242/256 114 LSA +3 would give you more of what you want, will also rev higher and still drive decent.
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Old 04-01-2019, 09:00 AM
  #82  
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Originally Posted by bortous View Post
If you are aiming for a NA engine why use dish pistons?
You are better off with flat tops.
The heads have relatively small chambers. A flat top with valve reliefs would result in too high of a compression ratio for pump gasoline, so a dish is pretty common with that much displacement.
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Old 04-01-2019, 03:44 PM
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Originally Posted by KCS View Post
The heads have relatively small chambers. A flat top with valve reliefs would result in too high of a compression ratio for pump gasoline, so a dish is pretty common with that much displacement.
This^^^ but for the ERL block -18 was way too much dish.
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Old 04-03-2019, 03:22 PM
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There isn't a lot of room for a big dish with a piston this short. Are they reverse dome of spherical?
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Old 04-04-2019, 07:18 AM
  #85  
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I run a 454 with 72 cc head and have the -3 dome/dish and it is like 11.8 to 1 compression (.051 gasket). So his engine is 3% bigger he would be just about 12.1 compression (assuming 72 cc head) so I could see with a 61 cc head he would need a good size dish.

Last edited by Double06; 04-04-2019 at 07:19 AM. Reason: adding stuff
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Old 04-22-2019, 08:42 PM
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A little progress report.

Old block is out and new one waiting to go in.




but first the transmission is header back to Rossler for a little refresh and to put it back on the computer. It's been running old school since I originally got it.



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Old 04-23-2019, 07:40 AM
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Welcome to the 468 brotherhood !!!!

Mine hits the engine dyno next month before I re-install into the car.
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Old 04-23-2019, 08:39 AM
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Nice build. In for results
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Old 04-23-2019, 12:59 PM
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Originally Posted by fnbadaz06 View Post
Mine hits the engine dyno next month before I re-install into the car.
Wishful thinking....it'll hit the dyno when I say it hits the dyno lol
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Old 04-23-2019, 01:52 PM
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Originally Posted by John B View Post
Wishful thinking....it'll hit the dyno when I say it hits the dyno lol
LOL ....... I'll delay it best I can
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Old 04-23-2019, 06:27 PM
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Originally Posted by fnbadaz06 View Post
LOL ....... I'll delay it best I can
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Old 05-08-2019, 10:26 AM
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Originally Posted by John B View Post
I see someone else chose to hit the rollers earlier this week.......... without me

Post those numbers and video up, John B !!!!!!!
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Old 05-08-2019, 04:50 PM
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Originally Posted by fnbadaz06 View Post
I see someone else chose to hit the rollers earlier this week.......... without me

Post those numbers and video up, John B !!!!!!!
What??? Yeah John B post up something!!
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Old 05-08-2019, 04:57 PM
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Originally Posted by Che70velle View Post
What??? Yeah John B post up something!!
It's up!
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Old 05-08-2019, 07:43 PM
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And badass....
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