CI/VI head setup questions


Supporter 2018
Supporter 2021
fast64ranchero:1rqpbl9u said:
Turbo choice is a EFR black series 8474. Unsure on what EFI will be used, I may start with Holley sniper to get it running.
At first I thought the 8474 would have a compressor that was too large for a 200 six operating at 7500 to 8000 rpm but I see that it is a hybrid based on the smaller 8374.
You may lose a little spool time response but the higher rpm flow is greatly improved over the 8374.
The 8474 is used by the racers pushing 900 hp and need a fast response.

Here is the 8474 map superimposed over the 8374 map.
The red line is the load line for the 200 six operating between 3500 rpm and 7500 rpm at 20lbs of boost with an engine VE of 95% trailing off to 88% with a 60% intercooler efficiency.
Notice that the engine would never be able to use the extended region of the map for the EFR 8474.
It would require the engine to operate near 10K rpm to get there.
Also consider there is less margin to the left at the surge region for the 8474 versus the 8374.

The Holley HP would be a good choice for port injection.
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Supporter 2020
Supporter 2021
I am thinking same a pmuller.A bit to big.
Make a great dyno racer, but not a great pavement racer.
Please when you are finished with the build please post up the part specs that you used and any info regarding them.
You are doing a fabulous (y) job.


Supporter 2018
Supporter 2021
I just updated post #41.
I'm very interested in this project.
AFAIK it will be the first time the aluminum head will have been set up properly with the right length valves, valve springs and port work to run the 200 to it's limit.
This also includes the aftermarket rods.

x2 on a job being well done!


Active member
Supporter 2019
Supporter 2018
After a couple of months of isolation, have you been able to make any more progress on this? I'm building a very similar engine for the roadster pickup I'm building... Would love to see some encouragement! :D :beer:


Well-known member
Sorry guys, Haven't been on in a while and, well, Life has changed. The engine should be in my "new project" 65 FB Mustang this month, and should be interesting.