BritishV8 Forum

Looking at the ports and the valve sizes I really don't see how it can be. I'll try to take some photos and post them tomorrow or the next day.

Jim

As Dan Jones explains farther down the page:

"Those Buick 300 heads were fitted with larger seats and Ferrea 6000 series Buick V6 Stage 1 stainless steel valves (1.775" intake and 1.5" exhaust). Intakes have a 10 degree "Super Flo" head shape while the exhausts are 29 degree tulips. The heads were hand ported by Jon Carls of JDC Engineering in Minonk, IL. I supplied Jon with a corroded Buick 300 head which he used to determine the casting material thickness limits. Given that the unported heads flowed 154/116 CFM @ 0.600" lift, he did a very good job. The exhaust to intake flow ratio and low to mid-lift numbers are quite good."

So apples to apples we're comparing 116 to 140 which is a quite significant improvement.
I think we may still need the comparison for OEM 300 heads to OEM 4.6 heads.

Jim

The Buick 300 heads on my 4.6 SD1 were originally modified on a flow bench by Holden/Ford V8 race head guru Eddy Woods at the Head Stud Development Co in Melbourne, and they were originally destined for a 5.0 litre Leyland P76 motor that went into an extensively lightened LC Holden Torana drag car.

They were later welded and re-flowed locally by Air Flow Developments and now flow 193 cfm at 550 thou (1.75 inlet). Which was quoted to support 405hp (bare). Standard P76 was about 132 cfm at the same lift (P76 heads were the same as the early Rover P6B heads). I think the later post 1976 SD1 Rover heads flowed about 148cfm at the same lift, with Stage 4 Rover heads around 181. Stock 300 heads flow 153 cfm at 550.

I believe Merlin F85 heads can be maxed out to flow about 185 cfm.
 
I read somewhere that Lanocha in the US flowed over 200cfm from Buick 300 aluminium heads which was sufficient to support 425 hp on a maximum-effort, high-compression, normally aspirated 5.0 litre TR8, and that's using a single-four-barrel Daemon Racing carb on a Willpower open plenum inlet manifold, not efi.

300 heads are softer than Rover heads being cast in 3000 aluminium. They can suffer from head bolt bosses spreading when torquing down, as well as loosening head bolts and rocker studs pulling out. Heat treating or re-tempering them to T-6 is claimed to improve matters, though I haven't done this myself yet.

I can confirm that the 215 heads were soft and would expect the 300 alloy heads to be the same. Thick washers on the head bolts are a necessity as thin ones can cone and allow the bosses to deform.

Jim

Rob, those number would be great for comparison, if it was known at what pressure they were tested.

In case anyone is interested, I just got off the phone with tech support at TA.  He said a few things:

1) The TA Rover heads combustion chamber can be opened up quite a bit, if necessary (they believe up to about 50cc or so).
2) The TA 350 aluminum heads (with 55.5 cc chambers) can be used if you use a 350 camshaft and turn down the camshaft journals (I saw a YouTube video proving this).  Their Stage 1 head claims to flow unported (at .500 lift) 222.3 intake and 144.4 exhaust, a modest "Bowl Blend" porting at 231.3 intake and 166.0 exhaust, and can flow a lot more with more aggressive porting.
3) The bare TA 350 heads weigh 25.4 lbs each.

It would be interesting to put these flow numbers in the comparison chart to make it easier to compare.  Unless I'm missing something, which is definitely possible, it does seem that the 350 head has a lot of potential--especially since with both the TA Rover TA or TA 350 heads will need spacers for the intake manifold anyway.  And the price is barely any more than the TA Rover heads.

Eric, The 350 heads ports are in different locations than the 215,300,340 and Rover. Deck height and width is close between 340 and 350. So, he made a 340 into a 350 with a lot of work and custom cam. The 350 heads are wider casting too. Do you have a you tube link?

Take a step back Eric. Just because a utube video shows it doesn't mean it's a good idea.

First off, TA themselves stated that the Rover heads had a better port layout than the 350 heads in terms of flow potential. May not be much but it's something. Bear in mind these were derived directly from their Grand National heads which are next-level good. The 350 heads came later and though the as-cast port size may be a little larger (but I don't know that it is) the geometry isn't quite as good. For a max porting effort, indications are that the Rover heads are better. I don't know that we ever did get suitable flow numbers from TA to compare the heads, only that one statement. And why would they when they want to sell the 350 heads?

Next, the 350 cam lobes are shifted by as much as 3/8" in the center of the engine and I doubt anyone thinks that's a good idea for reliability. You think rounded lobes are an issue now? Just try running on half a lobe.

No, we rather thoroughly explored the SBB/350 mix and match some time ago and concluded it wasn't such a great idea. Use the right heads for the engine.

Jim

Soft heads/ hard heads. Real unlikely TA heads are cast from T355 alloy( higher hardness retention than T356). That being said,
  Should someone put as many heat cycles through a TA head vs OEM heads, will likely find comparable loss of harness.
  What's not being addressed, the  benefit of using faster ramp rate cams with ported 300 heads. Take advantage of their, "flow sweet
  spot". They will not compare to TA heads at .600" lift, so don't try. How many Buick/ Rovers using .6" lift anyway ?
   Missed opportunities, not using roller cams optimized for the application !
                                                                                                   Art

Found the videos 350 heads on 300.

https://duckduckgo.com/?q=what+if+300+buick&iar=videos&iax=videos&ia=videos&iai=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DNaiGrO6DiTM

https://duckduckgo.com/?q=what+if+300+buick&iar=videos&iax=videos&ia=videos&iai=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DxovpZTM-qeQ

Jim B, thanks for the feedback.  Wasn't aware that anyone had looked at the 350 heads on the 300.  I did see a video that showed the cam lobes *might* be lining up pretty well.  But the valve placement and flow potential of the Rover heads vs the 350 heads is definitely something I was unaware (especially the Grand National lineage) that would make them a better pick.  And the fact that they have a lot of room for massaging the chamber (according to TA), might make them even better.  Good information, as always.  Thanks again.

In case anyone is interested in the videos that Jim N. posted, the ones to watch are the "What if 300" videos.

Like I said, just because it can be done doesn't make it a good idea. I suppose if you wanted to you could fit mushroom lifters and probably get by with it. Might get by with using roller lifters also. But to what end really? You couldn't use 350 intakes because they are too wide so now you have to build a custom intake. It's a whole lot of work and expense for very little if any gain, a risk of actual loss, and increased probability of mechanical failure. Better to stick with the 300 stuff. Now the 350 crank is a good idea, the Rover heads are too, including the 4.0/4.6L heads so that  TA heads can be swapped on later. Even the concentric oil pump is something worth considering. But 350 heads really shouldn't even make the list.

Oh and Art, TA could tell you the alloy but I have a set of their heads bolted to an iron block and the studs pulled torque just the way you would want them to. No indication of softness near the stud stretch point at all, like what you get with the 215 stuff. It came up to torque hard and solid. The heads have a good bit more meat in them than the 300 heads and it shows. It also makes them a few pounds heavier. I suspect the alloy is harder as well.

TA has been making aluminum heads and block for decades, including a wide assortment for the 455, somewhere between 4 and 6 distinctly different heads, a couple of different large displacement aluminum blocks for the 455 (up to 700 cu/in), blocks and heads for the GN, and now the Rover and Buick 350 plus a number of intake manifolds as well. They are very experienced with this, combined with extensive drag strip testing over the decades, and their business evolved from the old Kenne-Bell Buick racing parts supply. So they are a solid and dependable supplier with an exceptional track record both in actual racing, on the street, and in the aftermarket parts business. Pretty good people to do business with as well. I have no reservations at all in recommending their products, I've found they stand behind them and will make good on any flaw that might slip through the cracks as will inevitably happen sometimes. Not the bargain basement, but fair for what you get.

Jim

And so I went back, based on Jim B's feedback and TA's suggestion that the combustion chambers in their Rover heads could be opened up.  Assuming they can "safely" be opened up to that capacity, the numbers look pretty good.  Any suggestion on how I should define what "safe" means?  For example, would there be a way to have them determine the thickness of the material in the heads after? It's running pretty close to 11 to 1 compression--I'd want to make sure the heads could stand that.

My opinion is that opening up the combustion chambers is the wrong way to go, and for a couple of very good reasons. It may cost you a few hundred more to do but if you are considering the purchase of TA heads you can afford the alternative. And it eliminates probably over 20 hours of labor so if your time is worth more than say $20/hr it is worth it.

If you open up the chambers you lose any squish area the TA heads give you, reducing fuel efficiency and making the engine more prone to "ping" etc. Might just as well sit the pistons down further in the hole, the effect is much the same and is much easier to do.

You would also basically be destroying what are originally a great set of heads. Some may disagree, but really the heads are not the issue and neither is the combustion chamber. The real issue is the pistons. And if you are considering heads that will cost a bare minimum of $1600 even without valves and springs, it only makes sense to pony up the bucks for good pistons. If you do that the manufacturer will make the dish whatever you want it to be so why mess around with counter-productive work on your biggest investment in the engine? My last two sets of custom pistons from Wiseco, bought this year cost me $1100 a set and that was through my local machine shop. You may find cast pistons that won't work for as little as $200 a set but they won't be right for the heads and the engine. You may find forged pistons in the $400-600 range but to match bore, pin size, compression height and dish volume to what you need is going to be very difficult, time consuming, and likely ultimately unsuccessful. You can easily spend enough time on the quest to make the Wiseco pistons look like a very attractive option.

Now, if you've gotten this far, especially if you have the 350 crank and the ex-nascar rods, the next thing is the roller cam. From TA that's going to cost somewhere around $500. The lifters can be aftermarket Chevy at about $400 a set and you'll need a cam stop, so figure that as a $1000 option. By this point the engine cost is approaching $5K if you do most of the work yourself and you should be somewhat adverse to screwing up that size of an investment. So in terms of head work try to be a little more conventional. Sure, if you like, fit nice valves and springs and clean up the bowl areas a little. But remember what this engine is going in, a sub 2500lb car. You can be quite conservative and still have extremely good performance. There is no need to go all-out unless you will be racing it against similarly equipped cars and for the most part the guys in this group have nothing there left to prove. With that combo and a mild cam you should still be comfortably over 300hp, well into the muscle car range.

Which is why I mentioned starting out with the 4.0/4.6L heads. I just grabbed a set from the local pick-n-pull for $150 and the engine was pretty clean inside and had only a quite small ridge in the cylinders. I expect that with new seals I could use them as they are. I plan to use them on my 340 when it goes back together. It means I have to cut the piston dishes deeper but they are thick enough to do that. Then if I later feel a need to bolt on the TA heads it is a simple swap. The set of 300 heads can then go on the stock 300 (mule) and I'll have a set of low mileage iron heads that the Buick guys will likely be interested in.

Yes, you would be correct in thinking that this means I have 3 engines for my car, which does seem a little like overkill even for me and eventually I may let one or even two of them go. OTOH, once I've finished playing around with them the spares won't be eating anything and if I go out and abuse the engine in the car as I am somewhat inclined to do occasionally I won't need to be too concerned about it if there's another on the stand ready to take it's place. The other thing is that this whole scenario is evolving. The 340(350cid) Eaton blower equipped long rod engine was great. With the TA heads it would be even better, but I've retired that intake because it is too tall and won't work with the 300. The next intake will be built for the 300, specifically with the blower dropped down into the lifter valley but I've only just started on that. And nobody knows how long the flat tappet cam in the mule will last. So the 340 will go back together with the Rover heads and a stock (iron) 4bbl intake that will accept the intake system currently on the mule. That gives me more time to build the intake and blower/accessory drive. I do like having a spare available at a moment's notice and also having an engine available for development work. It's really the only way this works out that will allow me to always keep the car driveable.

I did get a bit OT but these are things you may want to consider in making your decisions going forward. In any case I do think it is a big mistake to hog out the chambers of that expensive new set of heads when there are other and ultimately better ways to go about getting from where you are to where you want to be, and the Rover chamber design is just simply better than the earlier Buick open chamber. The TA version is better still. Why mess that up?

Jim

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

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

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?

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.

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

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

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

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

Great, good to know.  Thanks Jim.

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.