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tips, technology, tools and techniques related to vehicle driveline components

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Airwreckc
Eric Cumming
RTP, North Carolina
(246 posts)

Registered:
05/28/2020 10:10AM

Main British Car:
1972 MGB-GT (working on a Sebring project) Buick 300-4 V8

Re: TA Rover Heads
Posted by: Airwreckc
Date: December 03, 2022 02:32PM

Good advice Jim. Hadn't thought about the cost of the head work and also what the effect might be on squish. I do like setting the aluminum 300 heads aside, as I have a 3.5 Rover block and with the 300 crank, I *think* I'm a long way down the path of making a stroker if something happens to my 300.

So, now I need to decide if I want to spend the money on the TA heads at all--might just (as you've suggested) start with some late model Rover heads and see what happens. However, I am wondering though if I go that route, how much a difference in cost there might be, since I'd have to spend some money to rebuild the Rover heads. I guess I could be lucky as you were and find some low mileage ones--an easier task than finding good 300 heads, for sure. But perhaps the difference in cost is not as great as it might appear?

Again appreciate the advice.

Eric


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: TA Rover Heads
Posted by: BlownMGB-V8
Date: December 03, 2022 03:48PM

The TA heads definitely have the best chamber design, more along the lines of the LS engines. It's been described as a heart shape though I'm not really sure about that but it is a design that encourages swirl for cleaner combustion. In short it complies with current design practice rather than 50 year old designs, bringing that part of the engine up to modern standards. The Rover head used a D shaped chamber and has less squish area and the 300 head had a predominantly round shape with very little space for squish at all and it was deeper IIRC. I could go out and look, probably do that tomorrow if I remember.

Then there's flow capacity. In a nutshell and my numbers are going to be off so this is more a guideline than anything else but to the best of my recollection and before porting it shapes up something like this:

215 and 3.5 Rover heads the intake flow at about .500 lift is going to be in the neighborhood of 120cfm
300 heads are going to be around 130-135 I think
Late Rover heads will be a bit less, not really sure how much
TA heads should be around 180
With good porting and big valves the 300 heads can approach the flow of unported TA heads.
With some porting work the TA heads can hit 220 without too much trouble I understand, and TA heads can be ordered fully CNC ported if desired, at a cost of nearly another grand.

I dunno, those numbers may be more accurate at .600 lift, it's been awhile since I looked. But as you can see the difference in flow from stock 300 heads to unported TA heads is substantial. Probably nearly a 50% increase depending on the size of valves that are fitted.

As for valve size, although it is possible to fit 2" intake valves, I went with the 1.9" intakes and 1.6" exhaust. We agreed that between shrouding and the very tight clearances it just made more sense for a street engine. But those sizes are a considerable increase over stock, and bearing in mind that this is to be a mildly boosted application I could see taking a slightly more conservative approach, which also was why I did not do any porting work at all. The higher flow velocities at low rpm should be helpful and at full chat there will be around 5psi of boost. May not sound like much but a 30% increase in flow will be noticeable.

Jim


Airwreckc
Eric Cumming
RTP, North Carolina
(246 posts)

Registered:
05/28/2020 10:10AM

Main British Car:
1972 MGB-GT (working on a Sebring project) Buick 300-4 V8

Re: TA Rover Heads
Posted by: Airwreckc
Date: December 04, 2022 10:36AM

Jim,

I was thinking that if I were to find some good later Rover heads, I might try doing the work myself--after all, if I screw it up, they are relatively cheap. Any thoughts as to the difference in horsepower, all things being equal, between some mildly ported Rover heads and unported TA heads?

Also, I'm guessing the intake manifold has some impact on all of this--I have two of the original aluminum 4BBL 300 intakes. I am quite concerned about hood clearance. so leaning in the direction of using one of these (with a 4BBL TBI, as I have previously mentioned). If I were to definitely use the 300 intake and EFI, does it make sense to still consider the TA manifold, or will flow in the manifold restrict things to the point that lower flowing heads like the later Rovers make more sense anyway?


minorv8
Jukka Harkola

(268 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: TA Rover Heads
Posted by: minorv8
Date: December 04, 2022 10:56AM

Unported TA heads should flow more than 180 cfm. I would expect to see something like 210-220 cfm. My Merlin heads flowed just over 180 cfm and my current Wildcat heads flow about 230 cfm with 1,94/1,60 valves. They are pretty much the same as TA heads. If you start porting Rover heads you will need big valves, serious porting etc etc. Cost is hard to estimate, dspends on what you can do yourself and what you need to have done by someone else. Unported TAs will have a lot of potential for future upgrades. I bought my Wildcats as bare heads, had to do a lot of porting, saved some cash by doing most of the job myself. Comparison to my ported Rover 4,6 heads and Merlin heads is easy. Wildcats are way superior heads. TA heads were actually number one heads on my shopping list but Wildcats happened to be available at right time for a reasonable price.


Airwreckc
Eric Cumming
RTP, North Carolina
(246 posts)

Registered:
05/28/2020 10:10AM

Main British Car:
1972 MGB-GT (working on a Sebring project) Buick 300-4 V8

Re: TA Rover Heads
Posted by: Airwreckc
Date: December 04, 2022 11:01AM

Jukka, thanks for the insight. Can I ask you what intake you're using?


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: TA Rover Heads
Posted by: BlownMGB-V8
Date: December 05, 2022 11:52AM

Eric, the potential for more power is there with the TA heads. But just potential. The rest of the system has to support it in order to see the results. In an MGB probably the biggest hurdle in terms of actually maximizing those results is the exhaust system. It's easy to understand why this is the case if you understand how headers are designed to work, and the headers available for the MGB could more properly be described in terms of flow potential as tubular manifolds. This is because the individual tubes are far too short to actually do any scavenging. So instead of having a vacuum pulse at the exhaust valve when it opens that will actively suck the burned gasses out of the cylinder and suck the fresh charge in, you have to rely on the pumping action of the engine only. You will see lots of experts saying that headers add 10-20hp but in reality it is far less simple. First off, headers do not add horsepower, lesser systems reduce horsepower. A properly designed equal length long runner header set is what you will see used at the engine dyno and that represents the maximum output configuration for that engine. Anything that flows less reduces output and that applies equally on both sides of the engine. So it is quite possible for an engine that produces 500hp on the dyno to produce 300hp in the car. A dirty little secret but no less true. In that example you would be seeing a 40% decrease in performance. It would be far better to look at this as a percentage than as a fixed number or number range, since the change on an engine making 500hp is going to be a far bigger number than on the engine making 100hp, even if they are the same basic engine but the percentage is likely to be about the same.

So you can see that it all depends. Obviously the difference between a perfect set of headers and a restrictive cast iron manifold would be greater than say with a set of shorty fenderwell headers, which represent an intermediate design. This also helps explain why a 375hp crate engine may not give quite the expected level of performance as installed. Are the full length headers worth the effort? As the long time owner of a set in an MGB with all that entails my perspective is undoubtedly skewed but I would have to say that yes it is. However it is indeed a great deal of trouble and means extensive work on the car itself to make it happen in the first place and practically nobody is willing to go to that much effort. In which case, the power output is going to take a hit. Maybe a substantial one. Still, any headers are usually better than iron manifolds and the factory had done quite well with the cast iron. so it really depends on your goals.

Now we go to the intake side. Overall American 4bbl intakes are quite good. The stock intake is designed for the stock rpm range of the engine which had a factory redline of 4800rpm. It will make more power above that redline but it's efficiency begins to drop off as restriction to flow increases. Clearly it is not going to match the flow potential of the TA heads. That is not to say that the TA heads aren't going to make very good power with it. Cylinder filling is dependent on time so at lower speeds the restriction of the stock intake will be less apparent. Also in normal driving the higher velocities are going to make the engine more responsive and contribute to better economy, at least in theory. Jukka may have some real world input on what intakes are suitable to such a build as this, certainly more than I would as I have concentrated more on blower intakes which literally changes everything. But I do know that there at least was a single plane intake available at one point and there is a new one in the works. That would be my go-to with the TA heads I think, although in a pinch I would bolt up the stock intake rather than not be able to drive the car. And it might do better than expected. Mike Moor ran a 305hp dyno pull with his car on a chassis dyno and I'm pretty sure he is running the stock 4bb intake. OTOH his dad is well versed in building and tuning the GN engine so that shouldn't come as a shock.

But the bottom line is that the potential of the heads is somewhat wasted if you fit a restrictive exhaust and a restricted intake. I'll give you an example. With the 455 in the MG-Roadmaster we fitted TA SE Eliminator heads because we needed the short exhaust ports and even so we had to use a tubular log exhaust. Aside from that the engine was fitted with a mild cam, an aftermarket 2 plane intake (Posten) and had 9:1 pistons. The dyno runs have not to date realized the expected power levels and for a number of reasons we are yet to see an actual dyno pull over 300hp. That's not to say the car's a dog by any means, the torque of that engine is simply massive, but most of the power loss can be directly attributed to the exhaust system, and where the potential output of the engine could be reasonably expected to approach 500hp it simply isn't there. Which is not by any means meant to imply that it is inadequate. Under WOT that car can be a beast. So maybe it needs pointed out yet again that 300hp kind of sets a dividing line above which the MGB will do anything you could want it to do. The target is much more easily achieved than with a heavier car.

Jim


Airwreckc
Eric Cumming
RTP, North Carolina
(246 posts)

Registered:
05/28/2020 10:10AM

Main British Car:
1972 MGB-GT (working on a Sebring project) Buick 300-4 V8

Re: TA Rover Heads
Posted by: Airwreckc
Date: December 05, 2022 12:13PM

Thanks Jim, good information. I guess the big unknown is if I build the engine with the stock intake and a set of shorty headers, does either the later Rover or TA heads make over 300 with that configuration? I would go with the Crower 50232 or maybe 233 camshaft that everyone seems to recommend. And I would, as mentioned, use TBI EFI. You're right, I probably won't go with long runner headers and I might stick with the stock manifold (perhaps extrude honed) because of hood clearance. But at least, I feel like I'm closing in on a configuration with your and everyone's advice. I appreciate it.

Eric



BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: TA Rover Heads
Posted by: BlownMGB-V8
Date: December 05, 2022 02:14PM

I think Mike used one of those 2 cams you listed, and RV8 headers or blockhuggers I'm not sure. He has the stock displacement. So yes, your target is reasonable and should be possible with the late Rover heads with maybe a little larger valves and a little light bowl work just to take down the sharp edges.

Jim


Airwreckc
Eric Cumming
RTP, North Carolina
(246 posts)

Registered:
05/28/2020 10:10AM

Main British Car:
1972 MGB-GT (working on a Sebring project) Buick 300-4 V8

Re: TA Rover Heads
Posted by: Airwreckc
Date: December 05, 2022 02:41PM

Great, good to know. Thanks Jim.


MGBV8
Carl Floyd
Kingsport, TN
(4511 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB Buick 215

authors avatar
Re: TA Rover Heads
Posted by: MGBV8
Date: December 05, 2022 02:45PM

Mike has the 50233 in his 300. On that dyno pull Jim mentions (I thought it was 308 hp), Mike had the OEM aluminum 4bbl intake manifold, the heads had a DIY home pocket port job, OEM 11:1 cast pistons, AND he was using the much maligned 215 block hugger headers.

Just shows, Eric, one can get to the 300 RWHP target without spending thousands of dollars on the best heads.



Edited 1 time(s). Last edit at 12/05/2022 02:45PM by MGBV8.


Airwreckc
Eric Cumming
RTP, North Carolina
(246 posts)

Registered:
05/28/2020 10:10AM

Main British Car:
1972 MGB-GT (working on a Sebring project) Buick 300-4 V8

Re: TA Rover Heads
Posted by: Airwreckc
Date: December 05, 2022 03:31PM

Good to know, Carl, thanks. Do you recall which heads Mike is using?--I assume the 300 heads, but wasn't able to find a specific reference. Yes, I'm thinking that while those TA heads would be awesome, if I'm going to use the standard intake and less than optimal headers, it's probably money better spent elsewhere (like on EFI that will make it more reliable).


MGBV8
Carl Floyd
Kingsport, TN
(4511 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB Buick 215

authors avatar
Re: TA Rover Heads
Posted by: MGBV8
Date: December 05, 2022 04:30PM

Yes, he uses the 300 heads that came on his 1964 Buick 300.

A few years ago, he had Terry Senneker build him a set of RV8 style headers more suited for his engine. I would love to see what it does on a dyno with those.


Airwreckc
Eric Cumming
RTP, North Carolina
(246 posts)

Registered:
05/28/2020 10:10AM

Main British Car:
1972 MGB-GT (working on a Sebring project) Buick 300-4 V8

Re: TA Rover Heads
Posted by: Airwreckc
Date: December 05, 2022 04:58PM

Good to know, I'll keep Senneker in mind for mine. Thanks.


minorv8
Jukka Harkola

(268 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: TA Rover Heads
Posted by: minorv8
Date: December 06, 2022 03:28PM

Eric, I am running a pair of throttle body manifolds for Wildcat heads. I fabricated a plenum on top of the manifolds and have a single 75 mm throttle body. These manifolds are a bit weird since the throttle body bolt pattern does not match typical patterns. I was planning to fabricate my own and actually did but ran out of time and bought Wildcat ones. Note that these have nothing to do with the Australian manifolds. They are manufactured by ACR in UK, the same company that also sells Wildcat heads.

Now, my previous engines had several intakes. The first one 3,5 ran a factory twin SU manifold and gave a whopping 190 hp. Not bad but also disappointing. That was soon fixed with a Performer intake (#2198 ?) and a Holley 390. Numbers were now around 225 hp mark. Holley was later replaced with a Edelbrock 500. Bottom end was then replaced with a 4,6 short block and this was maybe the best swap ever. A lot more torque and 50 hp more. All this with Rover heads. I then had the bright idea of buying Merlin aftermarket heads, then sold by Real Steel, nowadays sold by RPi. Both in UK. The heads are a huge improvement over stock heads but compared to my home ported bigger valve 4,6 heads only gave 15 hp extra, around 285 hp at flywheel. Again this with Edelbrock 500 and Performer intake. So, what next ? Single plane manifold naturally ! Difficult to find so I ordered one from Australia. Several months later it arrived and it was soon fitted. A textbook swap, lost bottom end torque and gained up top.

Everything (sort of) tested so it was time to get serious or humiliated so naturally one had to advance to EFi ! I had a Rover EFi manifold package that naturally needed porting, larger trumpets etc etc. I also ditched the factory MAF and used a front mounted throttle body. After a several weeks of frustration I got the engine running and gained 10 hp. And learned a lot abot what to do and what NOT to do.

The saga continues... now there is a stroked 4.6, new heads, new cam and intake, new gearbox and new ECU. Does it make any sense ? Maybe not... Did I learn anything ? No, especially from that part that says what NOT to do ...

I will post some pics tomorrow.


MGBV8
Carl Floyd
Kingsport, TN
(4511 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB Buick 215

authors avatar
Re: TA Rover Heads
Posted by: MGBV8
Date: December 06, 2022 03:34PM

Thanks for the rundown on your journey, Jukka. Are those flywheel numbers or rwhp?



roverman
Art Gertz
Winchester, CA.
(3188 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: TA Rover Heads
Posted by: roverman
Date: December 06, 2022 06:59PM

Good info Jukka ! If I don't run out of time.... I want a good single plane, with a telescoping plenum divider,( pulls up from floor).
Controlled by linkage or vacume. Onward, Art.


minorv8
Jukka Harkola

(268 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: TA Rover Heads
Posted by: minorv8
Date: December 07, 2022 04:39AM

My numbers are all @flywheel measured on chassis dyno.

Here´s some photos. First photo shows the unported manifolds as received from UK. The ports at flanges surfaces were machined but elsewhere the was quite a lot of material to cut.

Wildcat intake_1.jpg

Now, here is a ported manifold that I dropped to the floor. Nice quality of casting... Luckily it was good material to weld so no issues afterwards.

Wildcat intake_2.jpg

Here is the early stages of the plenum. There are stacks inside the plenum to lengthen the intake port. No math involved, just what fitted and felt right :-)

Wildcat intake_3.jpg

There was a lot of finessing later on, getting the coolant crossover fabricated and make room for it, making room for heater lines etc etc but eventually got it all working.


minorv8
Jukka Harkola

(268 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: TA Rover Heads
Posted by: minorv8
Date: December 07, 2022 04:46AM

Here is a photo of the final product. Not the cleanest of installations but maybe I will try to redo some details.

Wildcat intake_4.jpg


Airwreckc
Eric Cumming
RTP, North Carolina
(246 posts)

Registered:
05/28/2020 10:10AM

Main British Car:
1972 MGB-GT (working on a Sebring project) Buick 300-4 V8

Re: TA Rover Heads
Posted by: Airwreckc
Date: December 07, 2022 09:16AM

Jukka,

Thanks for the insight, especially the progression of numbers with different configurations. Your EFI system looks awesome, nice work. I'll be interested to see what you get out of stroking your engine, too--as that's what I'm planning. Lot's of similarities between what you have done and are planning to my plans--except I'll go with a more off the shelf EFI TBI.

Eric


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: TA Rover Heads
Posted by: BlownMGB-V8
Date: December 07, 2022 09:37AM

Last night at Happy Hour I got to look at flow numbers for the exhaust ports of Carl's 300 and Rover heads. For whatever reason apparently Max didn't flow the intakes. :-( We also compared photos of the runners, ports and chambers of the late Rover head, 300, and TA. Of note, between the 300 and 4.0 Rover, the intake valves in the 300 are larger but the exhaust is smaller. Port area increases from the 4.0 to the 300 to the TA and iron heads would be somewhere between the last two. Exhaust flow is noticeably better in the 4.0 head by a factor at .5 lift of about 100 to 120. At least partially due to the valve size difference. There may be some port geometry contributing. It's unfortunate we didn't have the intakes to compare.

I expect the 300 head flows better on the intake side and worse on the exhaust side, and this characteristic is consistent with pretty much all OEM Buick heads around that era and going back at least to the Nailheads and perhaps beyond. This supports the theory that the 4.0 heads are nearly as good as the 300 heads but until we have actual numbers a theory is all we have.

Jim
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