Dyno Results: MMS LS7 heads ERL 427 build has begun
03-31-2019, 01:11 PM
#81
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.
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.
04-04-2019, 07:18 AM
#85
TECH Enthusiast
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
04-22-2019, 08:42 PM
#86
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.
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.
05-08-2019, 04:50 PM
#93
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07-23-2019, 05:00 PM
#99
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Still conservative IMO, and a very wide split. On that 468 motor, i'd be thinking 252/266
Last edited by Darth_V8r; 07-23-2019 at 05:10 PM.
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07-23-2019, 05:39 PM
#100
ModSquad
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Agreed. I’m running a solid 254/268 .720ish” lift in a 434” and honestly it’s very drivable. Will be even more drivable once I find time to get Darth to do some street tuning for me. But really drives well, no kidding.