Buick 300 Stroker - One More Time

[Airwreckc]

And I found an old post from Jim B (to me). suggesting that opening up the TA heads is the wrong idea.  So, it may be custom pistons after all.

"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."

[mgb260]

Eric, I used 29cc for the Rover head in my calculation. Corrected to 37cc I get 10.43 with a 30cc dish.. DSS wants $629 for their standard forged pistons. I wonder how much more for custom?

[mgb260]

DSS already have a piston with 29cc dish, they would just have to change pin height to 1.29 and pin diameter to .912, if you went 3.8. Might not charge too much extra for that. Be nice to go down to 3.78 bore size.

[Airwreckc]

Thanks Jim.  I just emailed them with that very question.  I'll report back when I hear something.

As an aside, I did my calculation at 1.295 pin height, 35cc for the CC and 35cc dish, resulting in about 10 CR.