TRS TA Performance Cylinder heads

mgbloke · Post by **mgbloke** » Fri Jan 31, 2014 5:55 pm

Not managed to do much lately!
Been doing some mild porting and smoothing of casting marks.
Lloyd Specialist Developments in Warminster have offered to flow test my old self ported stage 3 heads v self ported Merlin heads v TA TRS heads.
Back to back on the same flow bench should make some interesting results.

Once my rear coil over suspension with mumford link is finished I will carry on with the engine.
As I will be spending a few quid on a stronger rear axle I have eaten in to my engine budget. All I will be doing engine wise is to fit The TA heads with new custom Forged pistons to get the CR up to about 11:1 and a new 248 cam.

Mark

Blown v8 · Post by **Blown v8** » Fri Jan 31, 2014 7:12 pm

A proper flow test of all three heads is something a lot of us have been waiting for !

minorv8 · Post by **minorv8** » Mon Feb 03, 2014 6:20 am

Which pistons did you order ? I take it they are 96 mm ?

Jukka

mgbloke · Post by **mgbloke** » Tue Feb 04, 2014 12:36 pm

Hi Jukka,
Havent ordered pistons yet as need engine in place while doing rear suspension modifications. Its slow going.

Will be flow testing the inlet valve only this Friday.

Cheers

mgbloke · Post by **mgbloke** » Fri Feb 07, 2014 7:29 pm

Flow tested the heads today. Waiting for the results to be emailed to me.
Very interesting results.
I didn't write anything down so this is from memory.
All tested on the same flowbench on the same day.

Standard 3.5 heads max 120cfm
Stage 3 41mm valve self ported 139cfm
Stage 4 TVR 500 heads 43mm valves, very nicely ported 149cfm
Merlin heads self ported 149cfm
TA TRS heads 174cfm
Both the merlin heads and the TA TRS heads had poor flow at small valve lifts compared to the stage 4 and stage 3 heads.

Will post exact details when I get them.

Daniel Jones · Post by **Daniel Jones** » Mon Feb 10, 2014 9:56 pm

What pressure drop (e.g. 10", 25", 28") were these heads measured at?

Thanks,
Dan Jones

mgbloke · Post by **mgbloke** » Mon Feb 10, 2014 10:15 pm

Daniel Jones · Post by **Daniel Jones** » Mon Feb 10, 2014 10:31 pm

So that means the TRS CNC ported TA Rover heads flow around 184 CFM at 28" through a 1.94" intake valve. Is that an average flow or peak value?

Dan Jones

mgbloke · Post by **mgbloke** » Tue Feb 11, 2014 7:23 am

That was peak flow.
I cant get my head around the fact that both the Merlins and TA heads flowed a lot worse at low valve lifts than the stage 3 head.
Also they were tested in a 94mm bore.

The TA Trs heads were not ported just removed very slight casting flash and machining marks.

Robrover · Post by **Robrover** » Tue Feb 11, 2014 7:42 am

Just for comparison the '64 Buick 300 alloy heads fitted to my 4.6 SD1 (ported by The Head Stud Development Co, Melbourne, Australia) flowed 191cfm @ 28" (550 thou lift / 1.75" inlets).

Eliot · Post by **Eliot** » Tue Feb 11, 2014 1:13 pm

mgbloke wrote:That was peak flow.
I cant get my head around the fact that both the Merlins and TA heads flowed a lot worse at low valve lifts than the stage 3 head.
.

Is it due to slower air velocity due to the presumably larger port sizes?

Darkspeed · Post by **Darkspeed** » Tue Feb 11, 2014 2:49 pm

mgbloke wrote:That was peak flow.
I cant get my head around the fact that both the Merlins and TA heads flowed a lot worse at low valve lifts than the stage 3 head.
Also they were tested in a 94mm bore.

The TA Trs heads were not ported just removed very slight casting flash and machining marks.

Two things for low lift flow issues - Seats and depending how far the low figures were on the lift - up to .150" chamber shrouding. But generally its poor seats.

Probably find the valves with a 3mm single 45 seat on them and a huge 45 on the insert.

Daniel Jones · Post by **Daniel Jones** » Tue Feb 11, 2014 5:17 pm

> The TA Trs heads were not ported just removed very slight casting flash and machining marks.
> Also they were tested in a 94mm bore.

Ah, that explains it. You had me worried the CNC ported version was only flowing 184 CFM peak @ 28". TA claims they flow approximately 225 CFM intake and 140 exhaust out-of-the box for the assembled heads but it's not clear if that includes any finish work like bowl blending. The guy at TA Performance said their Level II porting ($800 in hand labor, no CNC at this time) flowed 250/180 CFM with 1.94"/1.6" SBC valves (and presumably a pipe on the exhaust) but he didn't have any flow sheets to send. TA claims with additional porting they will go 270 CFM intake and 190 CFM exhaust. based upon your numbers, it looks like TA's numbers are optimistic.

As a point of reference, AFR 165cc heads are some of the best small block Ford smaller port (still larger than Rover) heads. With a 1.9"/1.6" diameter valves, at 0.500" lift, the AFRs flow in the neighborhood of 238 CFM on the intake side and 182 CFM on the exhaust. I'd be happy with that sort of flow out of the TA Rovers for my application but I think it will take a skilled head porter.

> I cant get my head around the fact that both the Merlins and TA heads flowed a lot worse at low valve lifts than the stage 3 head.

The TA heads have very deep valve seats. I bought mine bare and just eye balling them, they really need bowl porting. As others have pointed out, the valve job and valve back cut can have a strong effect on low lift flow.

> Just for comparison the '64 Buick 300 alloy heads fitted to my 4.6 SD1 (ported by The Head Stud
> Development Co, Melbourne, Australia) flowed 191cfm @ 28" (550 thou lift / 1.75" inlets).

Here' what my 1964 Buick 300 aluminum heads flowed:

Lift Int Exh
(inch) 1.775" 1.5"
0.100 66 47
0.150 99 82
0.200 129 104
0.250 155 119
0.300 174 130
0.350 187 139
0.400 191 146
0.450 194 150
0.500 196 152
0.550 200 153
0.600 200 153

We did a second set for a friend's MGB Olds/Buick 266 and it flowed a bit less:

Lift Int Exh
(inch) 1.775" 1.5"
0.050 26.3 22.6
0.100 56.3 51.6
0.150 86.8 75.0
0.200 124.0 101.0
0.250 148.0 117.0
0.300 166.0 128.0
0.350 175.0 140.0
0.400 182.0 145.0
0.450 185.0 148.0
0.550 189.0 151.0

The stock Buick 300 heads with 1.625"/1.312" valves flowed 154/116 CFM peak

Dan Jones

kokkolanpoika · Post by **kokkolanpoika** » Tue Feb 11, 2014 6:06 pm

It the inlet port flow say 210-270cfm @ 0.6- 0.7" valve lift.. How you can get that amount of valve lift? Using some super custom cam witch has got 9mm cam lift and 1.8:1 rocker ratio?

Not for street engine.. I do not see any point to port those heads to get more power.. You have to modify those ports to get more flow on on mild valve lift say 0.5"

Waiting for dyno run..

mgbloke · Post by **mgbloke** » Thu Feb 13, 2014 4:06 pm

I must admit I know nothing about flow dynamics.

Correct me if I am wrong and this might seem stupid but surely the importance is the amount that the valve, seat, port, runner etc etc can flow as a whole. The amount of time that a valve spends at low lift is small.
What matters is how much air can get past the valve through its complete opening and closing sequence.

The Merlin heads seem to perform better than the flow suggests! are there other factors that need to be considered?

Mark