Thread: TA Performance Rover V8 Cylinder Heads

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  1. #1 TA Performance Rover V8 Cylinder Heads 
    Young Brit
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    I just dropped off a set of assembled TA Performance Rover heads (1.94" diameter intake valves, 1.6" exhaust) and Willpower single plane intake at Stiegemeyer porting, a local cylinder head and supercharger specialist near where I work. I removed the valves from one cylinder and Bob examined the ports, chamber shrouding, seat margins and valve angles and asked me some questions about the engine the heads will be going on (a higher compression 4.2L Rover), along with how I plan to use the car (TR8, purely street). He also asked if I was going to run EFI or a carb, suggesting you can get away with somewhat larger ports with EFI. He thought the size of the as cast ports were fine for my purposes, needing only detail work, and that the best bang-for-the-buck would be to work around the existing valve job. He also threaded a spark plug in and indicated he would do a little chamber work around the plugs. Looking at the intake ports, he thought they should go to 250 CFM fairly easily which would be plenty for my application. The plan is to flow bench the TA Rover head in as delivered condition then let him have a go at bowl porting and port matching the heads and intake. He indicated that getting the port floor of the intake manifold to work with cylinder head port floor was especially critical. I'm going to drop a block, gaskets (intake, exhaust and head), a header flange with pipe stubs and some bolts off this weekend so he can mock it up. I think I'll also take an OEM 4.6L Rover cylinder head along to flow bench as don't have any data on unported Rover heads. The TA heads are based upon the TA Performance Buick V6 heads. The guy who designed the TA heads also suggested:

    "On the exhaust have him start by opening up the exhaust outlet, make the port wider, The port will respond by doing this. Then have him removing very little to none on the back side of the exhaust bowl. Just blend the machined throat area into the back side. He should end up with a slight bump even, on the back side. Blend the rest of the bowl how he see fit."

    The exhaust port shape is way better than the Rover/Buick but has been raised 3/4" so it's not clear if off-the-shelf TR8 headers will work. He also says the intake ports should flow 250+ CFM with only minor work. It'll be interesting to see what sort of power they make. It would also be interesting to test them on the 5.0L Rover V8 I have sitting at the dyno but the valves have been relocated to the center of the bore, have a different angle and are larger so chances are there will be piston-to-valve clearance issues.

    Given the bore size and chamber design, Stiegemeyer suggested no less than 11:1 compression and we briefly discussed camshafts. I mentioned the short block should handle a decent amount of RPM (cross-bolted mains, 3.03" stroke Rover nodular cast iron crank, Carrillo rods, forged flat top pistons) and I was considering running either a solid flat tappet or a hydraulic roller camshaft. He put the valve springs on a tester and said they were ideal for a hydraulic roller camshaft but recommended titanium retainers for a bit more RPM. He said they would also work with a solid flat tappet cam if offset locks were used to reduce the seat pressure. If running a solid flat tappet, he recommended using lifters with EDM holes supplying oil directly to the cam lobe/lifter face. On the tester, the springs were quite close to the advertised specifications. Note these assembled heads were delivered with TA's upgrade spring package for a hydraulic roller cam (TA p/n 1160) and have the following specs:

    Dual springs without damper
    O.D. 1.385
    160 lbs @ 1.900"
    360 lbs @ 1.400"
    400 lbs/in
    Coil Bind 1.175"
    Max Lift 0.650"

    He also likes the blue Viton metal clad valve seals, mentioning the white Teflon seals don't pass enough oil to the guides for most applications (uses them in race applications where the springs are flooded with oil over the top of the guides).

    Thanks,
    Dan Jones
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  2. #2  
    Young Brit
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    Just a quick update on the TA Rover heads. The head porter is supposed to get started on the Rover heads late this week. I dropped off the block, exhaust header flange, gaskets and head studs off last week so we could do a preliminary fit check prior to porting the heads. We positioned the TA heads and Willpower intake on the block without intake or head gaskets and the intake manifold bolt holes lined up with the holes in the heads and the intake ports were closely aligned with the unported TA head intake ports. Given the fact that the TA Rover heads are deeper, I expected the intake to sit up higher in the V and the holes in the intake need to be slotted but that wasn't the case. I assume TA must have adjusted those to match the wider head so the intake lines up. I didn't run the studs all the way down while I was there but the head bolt bosses are taller so its possible they won't be long enough. I'll check that this weekend. The blue Fel Pro Buick 300 intake gaskets (p/n 9944) are 0.042" thick and should work with the 0.050" Rover composite headgaskets. The gaskets are a decent fit but will likely need a bit of trimming and be shifted up perhaps an 1/8". I'll glue those to the intake before installation.

    I discussed Mike's information on porting the exhaust side and we put machinist dye around the exhaust port and bolted a header gasket in place. Widening the port per Mike's advice, he scribed an outline. The resultant port is sized for a 1 1/2" ID primary tube header. That means a 1 5/8" OD. The TR8 tri-y TR8 headers from the Wedge Shop are available in two sizes:

    Standard: 1 1/2" diameter primary, 1 3/4" secondary, 2" collector
    Big Tube: 1 5/8" diameter primary, 1 7/8" secondary, 2 1/4" collector

    I'll go with the big tube but the exhaust ports on the TA Rover heads are raised 3/4" and Woody says his headers tuck up close to the chassis so won't have the vertical clearance required. I'll have to cut and lengthen them.

    My block appears to be unmilled and specs for the Buick 215 and Rover show a nominal deck height of 8.96". The forged pistons have a compression height of 1.25". Crank stroke is 3.03" and connecting rods are 6.2" center-to-center:

    rod length + crank stroke/2 + piston pin height = 6.2 + 3.03/2 + 1.25 = 8.965"

    If the block is 8.96", that would put the piston 0.005" out of the hole at TDC. Close enough to zero deck. In the parts stash, I have a couple of larger bore Rover headgaskets:

    Rover ETC-7819 0.018" compressed thickness embossed head gasket
    Rover ERR-7217 0.050" compressed thickness composite head gasket 3.77" bore

    Unlike, the OEM Rover heads, the TA Performance Rover heads have a quench chamber. The usual quench distance goal is 0.040" +/-0.003" and the quench effect is supposedly negligible at 0.060". On the minimum side, you need enough clearance to compensate for piston rock at TDC and rod stretch at maximum RPM so the piston doesn't contact the head. Since aluminum blocks have a greater coefficient of linear thermal expansion, can probably run a little tighter quench. If I got my units correct, my back of the envelope calculation suggests maybe 0.006" difference between a cast iron and aluminum block for a 100 deg F temperature difference. Even factoring that in, the thinner headgasket is too thin to be safe. The thicker gasket will be thicker than desired but might be useable if the compression works out.

    The combustion chambers are nominally 35 ccs but will get polished so will likely end up around 40 ccs. I cc'd the piston dish and valve notch at between 11 and 13 ccs, depending upon whether I cc'd them with alcohol or white sand. Compression with these assumptions and the thinner headgasket would be 10.85:1 and 9.89:1 for the thicker headgasket. A 0.040" thick headgasket would give 10.17:1 compression ratio and the goal quench. Given the aluminum heads, small 3.706" bore and expected cam overlap, I'd like to be at 11:1 compression. That would be no problem with quench heads and quench pistons but the custom pistons I have were designed for Buick/Rover heads which have no quench to speak of and are dished in the location of the quench pad on the TA heads. The pistons were also designed for heads with the valves in OEM locations but the TA heads have relocated them to the center of the bore to permit larger valves. From the initial mock up, I should be able to modify the existing valve pockets for clearance, though the extra cc's will have to be figured into the final compression ratio. Given that Woody runs 11:1 compression in some of his engines that use Rover or Buick 300 heads, I should be able to run 11:1 without the quench effect. We'll see where it all ends up during the final mock up assembly but I'll likely have to mill the heads to get the desired compression ratio.

    I could buy another set of custom pistons designed for the TA Rover heads and swap the pistons over to the stock short block Rover 4.2L that I have. It will get ported OEM Rover heads but I'd also need to buy another set of 6.2" small (2.0") journal rods to make the compression height work out. Come to think of it, the guy I bought the parts of off tossed in a second set of 6.2" rods but I believe he said they weren't narrowed properly. Worth a look anyway.

    I also dropped of an OEM Rover 4.6L head for flow testing.

    Dan Jones
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  3. #3  
    Young Brit
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    Just got word from the head porter that the TA Rover heads should be ready for pickup next week. He said they flow near 260 CFM intake and 200 CFM exhaust. He noted that once you get past the intake port entries, the center of the ports looks like they were designed for a considerably larger displacement or higher RPM maximum effort application. If you raised the intake roof a 1/2" and epoxied the floor, he thought it would flow well over 300 CFM with a larger intake valve. Given the intake port sizing, he thinks the engine would run better with EFI than with a carb. He is really excited about the heads and the lightweight Rover/Buick engine and thought I should ditch the hydraulic roller, go solid flat tappet and spin it to 8000 RPM. He called a local engine builder over to look at the mock up of the heads, intake and block just because he thought it was so neat.

    More when I pick up the parts and flow sheets.

    Dan Jones
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  4. #4  
    Young Brit
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    Picked up the ported TA Rover heads today. Heads were ported by Bob Stiegemeier of Stiegemeier Porting Service (http://stiegemeier.com/) in St. Charles, Missouri and were tested at a 28" pressure drop on a SuperFlow 600 flow bench. Intake ports were flowed with a clayed radius around the intake port. No pipe was used on the exhaust except for one test with the stock 4.6L Rover head (noted below). Flow is in cubic feet per minute (CFM) and lift is in inches. Intake valve diameter is 1.94" and exhaust diameter is 1.6". Note that the heads were purchased assembled and Bob worked around the existing valve job. For my application, only minor work was required on the intake side so most of the effort was concentrated on the exhaust. Heads were flowed unported, ported and ported with a 30 degree back cut on the intake valves. Columns are as follow:

    1 = out of box intake ports
    2 = ported intake, no back cut on intake valves
    3 = ported intake, 30 degree back cut on intake valves
    4 = out-of-box exhaust ports, no pipe stub
    5 = ported exhaust, no back cut on exhaust valves, no pipe stub

    I'll try inserting periods to keep the forum software from screwing up the column spacing:

    Valve....1........2.........3........4........5
    Lift.....1.94....1.94....1.94...1.60...1.60
    (Inch)..CFM..CFM..CFM..CFM..CFM
    0.100 067.7 076.8 078.3 047.9 063.8
    0.200 105.4 120.4 129.4 070.2 108.5
    0.300 143.0 173.1 185.1 102.1 146.7
    0.350 164.0 198.7 206.2 114.9 -------
    0.400 185.1 224.2 225.8 126.0 177.0
    0.500 220.9 255.9 251.3 137.2 189.8
    0.600 225.8 ------- 252.8 140.4 199.4

    Bob noted the flow for the ported intake with back-cut valves was for the first one he did. He got closer to 260 CFM peak on subsequent valves. He believes he can do better if starting with heads without a valve job. The exhaust port was sized for a 1 5/8" OD header primary (the larger of the two available tri-y headers for the Triumph TR8). For reference, here's what my ported 1964 Buick 300 cylinder heads flowed with 1.775" intake and 1.5" exhaust valves:

    Lift 1.775 1.5
    0.100 066 047
    0.200 129 104
    0.300 174 130
    0.350 187 139
    0.400 191 146
    0.500 196 152
    0.600 200 153

    I had also previously flowed a stock Buick 300 head with 1.625" intake and 1.312" exhaust valves at 154 CFM intake and 116 CFM exhaust. The unported Rover 4.6L head flowed:

    Lift 1.575 1.350
    0.100 060.2 057.4
    0.200 105.4 092.5
    0.300 132.4 103.7
    0.350 135.5 106.9
    0.400 135.5 106.9 (114.8 with pipe stub)

    The ported TA Rover heads flow nearly double the stock Rover 4.6L heads! I dug up some small block Ford AFR 165 head flow numbers (CNC ported but earlier version with the 11/32" diameter valves) from a magazine article (Mustang 5.0 magazine, November, 2000, "Having our Heads Examined"):

    AFR 165 1.9 1.6
    0.100 060 051
    0.200 123 108
    0.300 176 149
    0.400 210 174
    0.500 232 184
    0.600 232 188

    Note the ported Rover TA heads outflow the highly regarded AFR 165 heads (best of the smaller valve size, stock port location, SBF heads).

    Bob clearanced the chambers to around 42cc then milled them 0.020" to get them to 37cc. He also installed thin wall bronze sleeves in the pushrod holes. The intake valves had sharp edges around the keepers and damaged some of the valve stem seals during dis-assembly so he smoothed the sharp edges and installed new seals. The intake valves (appear to be SI brand) were out of round so Bob cut them to get them round. The exhaust (Ferrea) were round and needed no adjustment. The intake manifold had a low spot on one of the flanges that he welded up and milled back down. The intake and heads were then port matched on the block. He tested the springs with and without the inner springs. With the inners in place, they are 170 lbs on the seat and 400 lbs @ 0.550" lift. With the inners removed, they are 120 lbs on the seat and 280 lbs @ 0.550". Bob said he can adjust the seat pressure with offset keepers once I decided on the cam. He'd really like to see me run a solid flat tappet cam with EDM lifters and beehive springs and spin the engine to 8000 RPM. Given the intake port size, he thought I'd want to run a narrower lobe separation angle than the intake valve diameter (to cubic inches ratio) might suggest with a bunch of initial timing and a short advance curve. He also suggested 11:1 compression and thought EFI would work better than a carb with the large intake ports. Given the very strong exhaust port, he thought a single pattern cam would be the way to go. He mentioned that while the exhaust would flow even more with a pipe stub, adding a full length header usually gets it back to what the naked exhaust port flows so he likes to flow them without a pipe stub. Bob was really jazzed about the TA heads and lightweight Rover V8. He noted there was room on the cylinder head to raise the roof a 1/2" and thought that raising the roof, filling the floor and use a larger intake valve, he could get well over 320 CFM out of the intake ports.

    Photos to follow later this week or weekend.

    Dan Jones
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  5. #5  
    This is great work and interesting to note that the intake fit with not adjustment on the intake. Do you know if you will have any trouble with the valley pan gasket setup? What are your plans there?

    Thanks
    Clint
    The Wedge Shop
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    www.thewedgeshop.com
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  6. #6  
    Young Brit
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    > This is great work and interesting to note that the intake fit with not adjustment on the intake.

    That surprised me too given the heads raise the intake up. It appears TA located the head intake ports to match the raised intake location. I'll take some pictures with the Fel Pro P/N 9944 blue Buick 300 intake manifold gaskets on the intake and on a head. I'll need to do just a bit of dremel trim work on the intake gaskets but they are close.

    > Do you know if you will have any trouble with the valley pan gasket setup? What are your plans there?

    The OEM valley pan gasket will not work. I plan to try to form one out of thin aluminum sheet. That would be curved like the OEM. Another approach would be to weld one up from a flat plate cover plus two circular arc section end pieces.

    Any idea what the maximum RPM you can safely turn with your hydraulic roller lifters? I need to decide whether to go with a solid flat tappet cam or a hydraulic roller for this application.

    Dan Jones
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  7. #7  
    Quote Originally Posted by Dan Jones View Post
    Any idea what the maximum RPM you can safely turn with your hydraulic roller lifters? I need to decide whether to go with a solid flat tappet cam or a hydraulic roller for this application.
    Dan Jones
    We like to keep the revs on the hydralic under 6.5k as they can pump up after that. You could go with solid roller and eliminate that issue.

    Thanks
    Clint
    Last edited by The Wedge Shop; 02-22-2016 at 12:07 PM.
    The Wedge Shop
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