Engine and Transmission Tech

I called TA Performance on Friday to see if they were shipping their Rover/Buick heads yet. Last time I talked to them they said they were in the final of three machining stages and should be shipping by now. Apparently they ran into a problem during the final stage (drilling and tapping of holes) were the metal appeared to be too soft. They contacted the foundry and had them pull the records. It appears that an undetermined number of the heads in this batch were not properly heat treated. It sounded like they are going to Brinell test the aluminum to determine how many heads were affected and how many will have to be sent back to the foundry for re-work.

Dan Jones

These heads seem to be made of unobtanium not aluminum. The whole saga resembles the Real Steel Merlin heads: lots of delays, excuses but very little info. How many heads have actually been sold ? Art has a pair but anyone else in this forum ?

I have more or less given up since TA could not give exact info and instead diected me to TRS for a pair that cost silly money...

The TA heads "should" be 356 with a T6 heat treatment. This material will "age harden" to some extent, but not to T6 hardness. This happens to be the least expensive casting aluminum, based on volume of material bought by foundrys. A few brands of race heads, use #355 aluminum, for it's superior hot strength, over 356. If you want to reduce thermal losses to coolant, you can slosh sodium silicate,(egg keep) , through the coolant passages and drain-out the excess. This also great for boats, to eliminate corrosion. Dan, if you find an excellent porting result, I might be interested. Proven results with these heads and the Merlins, seems elusive. Let's change that. Onward, roverman.

> The whole saga resembles the Real Steel Merlin heads: lots of delays,
> excuses but very little info. How many heads have actually been sold ?

I pretty much expected it. When you are a small volume producer and
don't have your own foundry, it's not unusual. A friend cast up the
IR EFI intake from scratch and had a foundry pour a batch of intakes.
He did all the tooling for a shop with a fancy multi axis machine and
waited for 6 months while they did nothing with it. He finally had to
re-tool and go to a shop with simpler machines that did a lot of
agriculture repairs.

> The TA heads "should" be 356 with a T6 heat treatment. This material will "age
> harden" to some extent, but not to T6 hardness. This happens to be the least
> expensive casting aluminum, based on volume of material bought by foundrys.

I know of racers who have sent overheated aluminum heads back to the
manufacturers to be re-heat treated. I don't know what sort of machine
work is required after the re-heat though.

> If you want to reduce thermal losses to coolant, you can slosh sodium
> silicate,(egg keep) , through the coolant passages and drain-out the excess.

That's largely what K&W block seal is. It's not a bad idea on an aluminum
engine to make the first fill of the radiator straight water and K&W to
seal up any porosity.

> Dan, if you find an excellent porting result, I might be interested.
> Proven results with these heads and the Merlins, seems elusive.

Will do. I'll probably be doing a less radical pair of heads than you
wish to do, though.

Dan Jones

Dan, I take it you have ordered these heads. Bare or assembled ?

> Dan, I take it you have ordered these heads. Bare or assembled ?

Bare. The rep at TA Performance said their Level II porting was $800
(hand labor, no CNC at this time) and should flow in the region of 250 CFM
intake and 180 CFM exhaust (likely with a port stub) with 1.94"/1.6" SBC
valves but he didn't have the lift reference for those flow numbers.
The fully assembled unported version are supposed to flow around 225 CFM
intake and 140 CFM exhaust. Note you will need a valley cover, valve
cover spacers, special guide plates, etc. to use the heads.

I plan on having the heads ported. I may have the guy that did my
Buick 300 heads do it. He charges $800 for his Stage III porting
(plus parts).

Dan Jones

I called TA Performance last week for a status update. They said
they had figured out which heads needed to be sent back to the foundry
for heat treat. They also said they were able to fill individual
customer orders by pulling from some large dealer orders. Just
got a UPS delivery notice so it looks like they should be here
sometime next week.

Dan Jones

Dan, FWIW, you might want to spot test for hardness, your heads. Not saying I don't "trust" TA, but they do have their share of problems. My heads came with masking tape over the dog-bone transfer ports. This was to contain the machining chips inside, during transit ? NOW I suppose checking my heads for hardness, would be wise ? "Maybe" 340 Buick rocker covers, will clear without spacers ? Good Luck, roverman.



Edited 1 time(s). Last edit at 08/06/2013 11:39AM by roverman.