Engine and Transmission Tech

Jim,

I don't *need* to heat treat them--however, I've recently read that heat treating can improve the strength of the head material, so that retorqueing as often is not required, as well as where the studs are located for the valve train. I've heard that it's a nice to have as the 300 heads have pretty soft aluminum.

Quote:

If someone were to find and post Dan's TA flow bench results that should be illuminating.

Here ya go:

[forum.britishv8.org]

Thanks Carl,

Those TA flow numbers are very helpful (I've pasted them below for reference):

Dan Jones' report of porting TA cylinder heads

Stock 4.6 heads with 1.575" intake valves,
vs. ported 300 heads with 1.775" intake valves
vs. out-of-the-box TA heads with 1.94" intake valves
vs ported TA heads with 1.94" intake valves
vs ported TA heads with back-cut 1.94" intake valves

'back-cut' means the valves were given a 30 degree back-cut.

---

Intake

Lift	4.6	B 300 P	Orig TA	Ported	back-cut
dia.	1.575"	1.775"	1.94"	1.94"	1.94"
0.100	60.2	66	67.7	76.8	78.3
0.200	105.4	129	105.4	120.4	129.4
0.300	132.4	174	143.0	173.1	185.1
0.350	135.5	187	164.0	198.7	206.2
0.400	135.5	191	185.1	224.2	225.8
0.500	n/a	196	220.9	255.9	251.3
0.600	n/a	200	225.8	(n/a)	252.8

---

Exhaust

Lift	4.6	B 300 P	Original	Ported
dia.	1.35"	1.5"	1.6"	1.6"
0.100	57.4	47	47.9	63.8
0.200	92.5	104	70.2	108.5
0.300	103.7	130	102.1	146.7
0.350	106.9	139	114.9	n/a
0.400	106.9	146	126.0	177.0
0.500	n/a	152	137.2	189.8
0.600	n/a	153	140.4	199.4

What's interesting is how well the ported 300 heads did. I'm wondering if anyone knows what a similar valve job (with the larger valves) and that porting might cost someone (assuming I could actually find someone who knows what they are doing)--I'm asking as I already own a pair of good 300 heads. And how much horsepower is reasonable to get out of those flow numbers without a crazy cam? Just curious if anyone has any thoughts. Trying to compare to the TA heads, which I found out are soon to be back in stock.




I edited in Paul Menten's excellent table version of the flow numbers. -Carl



Edited 2 time(s). Last edit at 08/29/2022 08:43PM by MGBV8.

What stands out to me is the flow of the unported TA exhaust. With a 1.6" valve, something there seems a bit off. I'd love to know why but I suppose that's something Dan would have to answer.

Jim

Jim,

I noticed that, too. I was surprised that the 300 head (ported) would be better than the unported TA head on the exhaust side.

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.



Edited 1 time(s). Last edit at 12/01/2022 03:37PM by Airwreckc.

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?



Edited 1 time(s). Last edit at 12/01/2022 04:41PM by mgb260.

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.

[duckduckgo.com]

[duckduckgo.com]



Edited 1 time(s). Last edit at 12/01/2022 06:26PM by mgb260.

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