Single plane vs Dual plane 300 stroker with TA heads.

[mgb260]

Chad, this is with individual throttlebody fuel injection and 1 5/8" headers:

[mgb260]

That was with 300 heads with the biggest valves to fit the stock seats. 1.69 IN and 1.39 EX. I'll dio with larger valves like I used before 1.74 IN and 1.5 EX.

[mgb260]

1.74 IN and 1.5 EX

[mgb260]

Now with TA heads 1.9 IN 1.6 EX

[Roverbeam]

Thanks for all that, Jim!
I started this engine project thinking "1 per cube", then saw the over-350 numbers and thought "wow!" The Pipemax result is formatted as a text "report", and includes the cam specs it'd like to see for the higher levels that it reports: 228-233in / 231-236ex & 107-107.5 separation.

Interesting that the 300 heads have concave-down ("fuller") torque curves, versus the concave up ("hollow") torque curve for the TA's. I think by the time the 300's are working as they should, with all the supporting parts and machine work, I'll be a fair bit more expense than the TA's, so the graph with the extra area under the curve helps ease my conscience!

"Never underestimate the human ability to rationalize."

[mgb260]

Smaller valves help low end torque and give sharper throttle response.  Lower but broader torque curve.

[mgb260]

Chad, I didn't know if I could print this, Engine label is wrong but is for the Rover 300 crank stroker. TA heads. Asterisks on timing are set to prevent pinging. Click twice to expand.

[ag1234]

Price and supplier of roller cam ?
                                               Art.

[Roverbeam]

I got a hydraulic roller cam and lifters from The Wedgeshop. Their process is to have a chat with Woody, then he develops a cam spec that is fulfilled by Erson. It was 1100 cheaper (HALF!!) when I bought it:

https://thewedgeshopstore.com/roller-cam-setup-rover-v8/

[MGBV8]

"Hydraulic roller cams are not meant to rev past 6500rpm"

I'm out.  

[Roverbeam]

I'm pretty sure a 60 year old 300 crank ought not go past 6.5k either!

Going solid and using all the revs entails using big springs, which the 300 aluminum heads can't take. I was advised to keep spring pressure under 400, to avoid pulling the rocker shaft bolts out - and that, after installing Keenserts or similar. So, the whole package has a roughly 6.5k limit, I guess.

I noticed some of Kent's spicier cams (234, 238, 248 I think are the part numbers) all call for their generic double spring upgrade. Other sites (3rd party sellers) say those springs are 260# open.  I'd call to verify that Kent's website isn't lying about the springs to go with those cams, but price wise a Kent cam is under $400, and TWS hyd roller lifters are under $600. That combo sure beats the price of the TWS kit right now.

[MGBV8]

My 1963 215 crank has spent quite a bit of time at 6-6.5K.  Even a few trips to pegged the needle at 7K.  Probably not a good idea, though.  

[BlownMGB-V8]

The crank is not a problem. GS Johnny has been running the SBB up to 7500 rpm for decades now and has never had a crank failure. I think he saw something like 9 grand when he banged into the wall and the engine was still good.

You do need more valve spring and whether or not you have to have solids above 6500 is more a function of spring pressure vs valve train weight than anything else. You can boost the pressure and remove weight to rev higher and/or you can go to solids. No more than we drive these cars a winter lifter adjustment should be reasonable for most of us. Wasn't the 4 banger equipped with solids?

Beehive springs can reduce the weight along with upping the spring pressure. There's a thread that gets pretty deeply into that but I don't have the link.

TA sells roller cams. You buy the core and then pay for the grind. Not cheap but then you can run modern oils with it which is an advantage.

Jim

[mgb260]

Chad mentioned the rocker shaft hold down bolts pulling out. I personally know of 4 people having that issue. All with the softer 300 heads. Steel inserts with Loktite is a good idea, especially with high spring pressure.

[Roverbeam]

The fella from whom I purchased some Buick headers (and engine...) had drag raced 300s, 350s, and big block stuff too. He said that the crank wasn't the problem with the 300s, as Jim says. But for road course/sustained higher revs, it just doesn't seem like a good fate to tempt. Maybe as the rest of the package comes together, I'll get a little less skeered, but it seems like there's plenty of useful power below six and a half, and it's quite a bit harder to get the rest of the parts to be happy at 7k as well - like the solid vs hyd roller discussion above, Ti vs chromoly vs tool steel vs mild steel retainers, conical vs beehive vs double springs, and on and on. Limiting myself to 6.5 means I'm still trying to get "good" versions of each component, without feeling like needing to buy the absolute be$t.

[Airwreckc]

Chad, I'm there with you, as well.  Trying to build a "good" but not "best" engine.  Sounds like you'll be ahead of me, so I'd be interested in what you come up with.  Did I read that you're going with the 300 heads?  I did splurge a bit and bought the TA heads, but my engine is in storage, so it'll be awhile before anything is done.

[ag1234]

To clarify, you reduce main sizes to 2.5"?  Where do oil holes wind up ? Then you twist for maximum HP at 6k.?

[Roverbeam]

300 crank and later (4.0, 4.6) Rover mains are already compatible, but Rover (4.0, 4.6) big ends are bigger than Buick 300.

Early Rover used smaller mains, but same size big ends as Buick.

There's a handy chart on this page:
http://aluminumv8.com/Home/Displacement

As far as targeting a particular rpm, both the Pipemax predictions I've done, as well as Jim's dyno software, seem to show the combination not running out of breath until around 7, provided the flow inputs can be matched by reality. So far none of the choices I've made would lead me to think I've got to worry about breakage at 7, but I haven't gone for a valve and spring and lifter and head package that I absolutely know won't float past 6.5. To guarantee stability at 7, I'd think about spending more on those components. That's the thought process I've used to make my purchase decisions - feel free to nudge me differently if you see a logic failure in there!

[BlownMGB-V8]

On the 340-350/300 stroker crank setup, yes the oiling holes do migrate across the main journal a bit when you cut down the mains. A little judicious work with a die grinder gets you back in the center. Then the mains are ground and polished normally. Don't overlook the seal journal. Honda or Toyota rod journal sizes used with Nascar take-out rods (Carillo, etc) gets you back to a standard size on both rods and mains but be aware, some sizes only have standard size racing shells available, so if you have to replace the bearings on down the road it may become necessary to prep another crank or swap rods. Careful rod selection can avoid this.

Incidentally I have a standard 300 crank available if anyone needs one.

Did you buy the bare heads or complete? If bare have you decided on your valve sizes? TA heads can go up to a 2.02" intake with a 1.6" exhaust valve but that requires you to siamese the seats. Which can be done but it does add another potential failure point. A 1.9" intake with the 1.6" exhaust avoids that problem and makes use of the seats the heads come with. It's about as big as you can go with the seats as supplied. But, that's a big step up from any of the OEM heads. It also eliminates any concern about shrouding. I was lucky enough to find some good used titanium valves I could make work, but had to shorten the stems and cut down the heads of the intakes. In the process getting into the whole keeper/retainer issue including angles and groove designs. But these valve weigh about half as much as stainless. Spring height is another issue you can play with, the TA heads are designed to take a taller spring than the OEM heads. There is a good beehive spring that will give you somewhere around 300-350 lbs on the nose and maybe 150 seated. Those numbers are good for 6500-7000 rpm with a 1/2" lift roller cam. The decreased weight of the beehive springs is an advantage, as is the coil stability at speed but you have to run them close to coil bind to get that last benefit. So your calculations are important.

Also important are the weights of your pistons and rods. A good forged piston should come in under 500 grams, a good rod not much over that. You can drop nearly 100 grams by using a light weight wrist pin. The crank bobweights are lightened as a consequence. All of these things matter and result in a more responsive engine. Should be standard cost for balancing. The later 350 crank should be heavy enough to allow internal balancing without adding mallory slugs which can allow you to use Chevy flywheels and balancers without an offset weight, reducing the cost of those parts. The Chevy flywheel requires one hole to be elongated a bit to match the Buick indexing. Not really sure how much of an advantage this is, as matching Buick parts are available at competitive prices.

TA carries a paired roller rocker set that uses the stud mounting and is an economical choice. Uses guide plates. Be aware that the cheap import chevy roller rockers have a history of bearing failures.

If you are going to the trouble of enabling 7k on the top end it just makes good sense to properly prepare the bottom end as well. The resulting engine's performance in an MGB will be outstanding.

Jim

[Airwreckc]

Jim,

I got my heads bare--they would not sell them as complete as they told me they are backed up by over a year on head work.  Having said that, I am definitely going to go with your suggestions and stick with the standard valve seats with the 1.9" INT and 1.6 EXH, which, as you mentioned, is already a big improvement over the stock heads.  I will also go with the TA roller rocker set you suggested (as well as the Buick flywheel, which I believe they offer).

Regarding your comments on the Nascar takeout rods, I have a set of Ford rods, which I thought has the standard sizes, but now I'm wondering what you mean by "standard size racing shell"?

Once again, the advice here is invaluable

[BlownMGB-V8]

Eric, I don't remember the exact details but I bought two sets of 6.2" nascar take-out rods. One set was Carillo and the other was... Pankel? Not sure, they were bought by Carillo and are better in some ways and not in others. (Had a better split interface) They used two different brands of big end bearings both around 1.9", maybe one was Toyota and the other was Honda bearing shell inserts. As it turned out one was pretty common with a variety of bearings available and the other was a one size racing insert. I do not remember which was which so if you see a set of rods you like that is a thing to check out before buying them.

But my point on the nascar rods is that for around a hundred bucks you can have the best rods available anywhere. Then you take what you saved on the rods and spend it on a good set of custom pistons where you can specify every detail so they match your needs perfectly, and then without spending too much money you have a bulletproof bottom end in a perfectly designed engine. Even if you spend $1200 on the pistons, that's still only half that if you split the budget between the pistons and the rods and $650 for a set of custom forged pistons is quite a nice price. It's a handy way to justify it. And then you get to spec out not just the bore size, pin size, compression height, squish distance, skirt design, dish and CR but also ring package size and type, pin locks, gas porting, oil drainback holes, coatings if desired, and any number of other details you can come up with. Spec out light weight tool steel wrist pins at the same time and drop even more weight.

But do not choose teflon buttons. They are nice but they are heavy and unless the engine will be torn down often there is just no need for them.

Jim

[Airwreckc]

Jim,  thanks for the additional details--the approach you've suggested is definitely what I'm going to pursue.  Should make for a strong and reliable engine  Now, if I can get one of the piston companies to return my call.  Best, Eric

[BlownMGB-V8]

I bought Wiseco through my local machinist, let him make the calls.

Jim

[Airwreckc]

Makes sense, thanks.