Yes, they charged a little extra for the larger seats for those valves. And yes Chris will do before and after flow sheets with velocity readings as well. The valves are back ordered and Chris just had surgery so not sure how quick things will go. Pics to come ASAP
The iron and aluminum heads were flowed back to back with each other to have accurate comparable numbers. TA Performance “Budget Bowl Blend” is a new introductory low cost porting option that we’re offering for customers who choose to have us assemble their 350 heads. For $200 we will port your heads which will result in average gains of 10 cfm on the intake and 25 cfm on the exhaust. Our next porting option is a Level 1 for $700. The TA 350 Stage 1 SE heads are machined to accept stud mount (Chevy style) rockers. All that is required is that the rocker towers are milled off. You can take the heads to a machinist and have them do it, or TA can perform the service.
For comparison I'd like to re-post the results Dan Jones had with the TA-Rover heads: "I thought I'd share some numbers for a set of TA Rover heads I had on a flow bench recently. The heads were first flowed in unported form and then ported by Bob Stiegemeier of Stiegemeier Porting Service (http://stiegemeier.com/) in St. Charles, Missouri USA. In addition to the heads, I dropped off a Willpower single plane intake manifold, exhaust header flange, block and assorted gaskets for mock up purposes. I also dropped off an unported Rover 4.6L cylinder head for comparison purposes. This set of heads started as an assembled unported set from TA Performance with 1.94" diameter intake and 1.6" diameter exhaust valves and an upgraded spring package. We started the evaluation by removing a pair of valves from one cylinder. 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 (cross-bolted Rover 4.2L with Carrillo rods, Wiseco forged pistons for a street driven Triumph TR8). He also asked if I was going to run EFI (yes) or a carb, suggesting you can get away with larger ports with EFI. Since the heads were assembled, we decided the best bang-for-the buck would be to work around the existing valve job. Looking at the intake ports, Bob noted the as cast port size was plenty large for my application and thought they should go to 250 CFM easily with only minor work. He also threaded a spark plug into the head and indicated he would do a little chamber work around the plugs and polish the chambers. Bob used to do development work on NASCAR intake manifolds and mentioned getting the port floor of the intake manifold to work with cylinder head port floor was especially critical. Bob pulled out some exhaust port templates and asked about the headers I planned to run (1 5/8" primary TR8 tri-ys). Bob said the shape of the exhaust ports looked good but would need to be made wider. I'd previously contacted the developer of the heads, Mike Tomaszewski of TA Performance, and he had the following to say on porting the TA Rover heads: "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 remove 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 sees fit." The heads 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. 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 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 67.7 76.8 78.3 47.9 63.8 0.200 105.4 120.4 129.4 70.2 108.5 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. 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: Ported 1964 Buick 300 cylinder head Lift 1.775" 1.5" Inch CFM CFM 0.100 66 47 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: Unported Rover 4.6L cylinder head Lift 1.575" 1.350" Inch CFM CFM 0.100 60.2 57.4 0.200 105.4 92.5 0.300 132.4 103.7 0.350 135.5 106.9 0.400 135.5 106.9 (114.8 with exhaust pipe stub) With minor port work, the ported TA Rover heads flow nearly double the stock Rover 4.6L 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. Though I'm considering a hydraulic roller, Bob would 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, along 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. Bob said he could do better on the intake side starting with a bare set of heads (not working around the existing valve job) and 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 over 320 CFM out of the intake ports. " Dan Jones Obviously these heads flow rather well to start with and respond even better to porting work. Looking at the numbers posted above they would compare very favorably with the 350 heads, but we've only begun do see what the 350 heads are capable of. In any event, Well Done, TA, and well done Dan and Bob! 320cfm out of the 350 heads? Who will be the first? Let's raise that bar. (Of course I'm just egging you guys on. Even after I've bought the Rover heads I'll be using a blower to get my power fix.) Jim
Any idea what we can expect from Level 1 porting, or is that a question better asked with a phone call? Would the numbers posted earlier from your hand porting be equivalent to Level 1 porting?
Based on what I observed when I ported my heads: A Level 1 will probably be around 260 cfm intake 190-200 cfm exhaust. A Level 2 will probably be around 275 cfm intake and 200 cfm exhaust. A Level 3 will probably be around 280-285 cfm intake and 205 cfm exhaust. To be completely honest, I'm not super interested in doing more than a Level 1 at this time. It's extremely time consuming and I have a lot on my plate as it is
Curious... would stock stamped steel rockers fit on the heads? Is the machine work to mill the towers off plus the provided equipment (TA provided rockers and studs) be cheaper than the TA roller shaft rockers?
I’m sure michael will chime in but yes I’m sure there is an opportunity to save a bit of $ to go with the SBC rockers. I don’t think it’s a huge savings.
Stock stamp steel rockers will work. Michael has been working through many different options and data gathering on these heads. We did dyno Michael's 350 engine, made 50 pulls. Back to the heads, were trying to work up pricing for options. We have made a few test guide plates out of steel but have not made a run of hardened guide plates yet for Chevy style rockers. I am working on getting sample guide plates made for testing from a stamping plant. I worked on two sets of TA Roller rockers yesterday figuring out what needed to be done to locate the exhaust rocker roller tip on the center of the valve. I'm going to put a kit together for purchase with instructions of what needs to be done. To give you an idea. The center spacer needs to be shortened .200", each exhaust rocker needs to be shimmed over towards the cylinder with a .120" worth of shim. The end exhaust rockers then need to be retained with a 3/8-24 x 5/8" bolt, a large washer and .180" of shims. For really old TA 350 roller rockers that do not have drilled and tapped rocker shafts, unfortunately either sell them to someone with iron heads or you will need to purchase new shafts. I do believe that 500 hp, pump gas, street driven, 350 Buick's are in our future.
What constitutes "really old"? Mine are '95-'96 models. What do you mean "drilled and tapped"? I just ordered new shafts and roller bearings a month ago for mine.
Ahhh ok the "drilled and tapped" makes sense now, I was wondering what difference it made if the shafts were drilled and tapped, but I see now, if the end exhaust rockers are moved, the groove for the snap ring on the ends of the shafts will now be covered by the rocker
if the so-called 70's are supposedly 10:1 comp, how much does c/r change using these? pics of the rockers, ratio ?. I use 1.65's now. any issues?
