Independant flow testing on PRC 237 heads (with intake as well)
Independant flow testing on PRC 237 heads (with intake as well) I bought these heads used, bolted them on to my 418 and made 546 rwhp with it falling off at 6,800 due to valve float. Took it to the track and saw the same issue (ran numbers in sig). Pulled the heads off and sent them to TEA for LS3 valves and new guides. When doing the valve job the blended the chamber where they had to cut in to the seat sinking the valve ever so slightly.
Once back I sent them and my intake to a local guy to port the Super Vic. Once ported he flowed one of the center 4 ports and then attached the intake. Exhausts he flowed with and with out a 1 7/8 OD pipe (1 3/4 ID).
Lift -- No Intake -- With Intake -- No Pipe -- With Pipe
.100 ---- 70.5 -------- 70.5 ------- 57 -------- NA (or same, did not put numbers)
.200 ---- 145.7 ------- 145.7 ------ 121 ------ NA (or same, did not put numbers)
.300 ---- 218 --------- 218 -------- 176.8 ----- 186.5
.400 ---- 272.7 ------- 272.7 ------ 211 ------- 232.5
.500 ---- 313 --------- 307 -------- 224 ------- 247
.550 ---- 328.5 ------- NA --------- 228.5 ----- 253
.600 ---- 343.8 ------- 330.5 ------ 231.5 ----- 254
.650 ---- 354.8 ------- 332 -------- 232 ------- 261
.700 ---- 365 --------- 337 -------- 234.5 ----- 264
From .200 to .500 flow is 1-4% less than TSP advertises, but that could be many reasons the flow bench, a different valve job etc. .600 and .650 we saw better then advertised results (2.9% @ .600 and 4.7% at .650)
I thought I would see more loss with the intake. 0% to .400 and 2% @ .500 growing to 8% at .700.
Just thought I would share the results.
Once back I sent them and my intake to a local guy to port the Super Vic. Once ported he flowed one of the center 4 ports and then attached the intake. Exhausts he flowed with and with out a 1 7/8 OD pipe (1 3/4 ID).
Lift -- No Intake -- With Intake -- No Pipe -- With Pipe
.100 ---- 70.5 -------- 70.5 ------- 57 -------- NA (or same, did not put numbers)
.200 ---- 145.7 ------- 145.7 ------ 121 ------ NA (or same, did not put numbers)
.300 ---- 218 --------- 218 -------- 176.8 ----- 186.5
.400 ---- 272.7 ------- 272.7 ------ 211 ------- 232.5
.500 ---- 313 --------- 307 -------- 224 ------- 247
.550 ---- 328.5 ------- NA --------- 228.5 ----- 253
.600 ---- 343.8 ------- 330.5 ------ 231.5 ----- 254
.650 ---- 354.8 ------- 332 -------- 232 ------- 261
.700 ---- 365 --------- 337 -------- 234.5 ----- 264
From .200 to .500 flow is 1-4% less than TSP advertises, but that could be many reasons the flow bench, a different valve job etc. .600 and .650 we saw better then advertised results (2.9% @ .600 and 4.7% at .650)
I thought I would see more loss with the intake. 0% to .400 and 2% @ .500 growing to 8% at .700.
Just thought I would share the results.
Last edited by LIL SS; Apr 24, 2013 at 12:21 PM.
Am I happy with the heads? Yes.
Should I have bought them new with powder metal guides and LS3 valves from the get go? Yes
I am hoping with the changes made I can spin it to the 7,400 I want.
With the additional changes below, I am hoping to get closer to 600rwhp which will ultimately help me get closer to my 9.9x NA and 8.9x N20 goals.
Ported reducer for TB (4500 to 4150)
Massaged N20 plate
Ported intake
Vacuum pump
Mezeire EWP
Have a set of 1.8 Yella Terra to try
Should I have bought them new with powder metal guides and LS3 valves from the get go? Yes
I am hoping with the changes made I can spin it to the 7,400 I want.
With the additional changes below, I am hoping to get closer to 600rwhp which will ultimately help me get closer to my 9.9x NA and 8.9x N20 goals.
Ported reducer for TB (4500 to 4150)
Massaged N20 plate
Ported intake
Vacuum pump
Mezeire EWP
Have a set of 1.8 Yella Terra to try
Staging Lane
Joined: Jul 2009
Posts: 85
Likes: 0
Are you going to throw all those additional mods on at one time, or do them a little at a time to see where the most gains come from? Just wondering. I have been kicking around the idea of getting a GZ vac pump for my build as well.
Be interesting to see how much the EWP free's up in your build. Didn't do much for me in terms of gains on my old 347. I thought it ran cooler though LOL.
Be interesting to see how much the EWP free's up in your build. Didn't do much for me in terms of gains on my old 347. I thought it ran cooler though LOL.
Those look very nice! If you are interested in comparing flow #'s to a set of of TF235's that have been extensively modified I can post that up.
The heads are back on the car & running, no dyno numbers as of yet to report.
The heads are back on the car & running, no dyno numbers as of yet to report.
Sinister, depending on time, I will dyno with mechanical pump, stock 1.7 rockers, belt off cvacuum pump then add 1 component at a time. I did not go with a GZ, I have a morosso 4 vain.
CTD, I don't mind, but you might want to start a new thread so others can easily find it for reference in the future.
CTD, I don't mind, but you might want to start a new thread so others can easily find it for reference in the future.
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