Reply With QuoteNever used them in a Ford but in lots of SBC&BBC with great life. Allways with a cast iron quick seat ring. Speed Pro makes quality stuff as far as I see it.
Mike :notam:
Anybody Had Any Trouble With The Bbf .400 Dome Speed Pro(trw) Pistons?
Mike :notam:
Anybody Had Any Trouble With The Bbf .400 Dome Speed Pro(trw) Pistons?
That piston is an older design from TRW that was originally conceived as an answer to the 97cc D3VE cylinder head...to get compression up. The .030" overbore dome top piston to which you are referring brings the D3VE headed 460 to about 10.66:1 (higher if you shave the heads).
The only primary difference in combustion chamber shape between the early style (D0VE) heads and the late style (D3VE) heads is the depth of the chamber, in that the D3VE head has it's chamber dropped into the cylinder head by another .100". So, those pistons also work in the early style heads quite well and give really great compresion, like 13.2:1.
The L2443-030 dome top piston design has had slight changes over the years since Federal Modul (Speed-Pro) bought TRW in 1995 but is essentially the same configuration.
Piston design overall has come a long way since that piston came out. It is on the heavy side these days and uses 5/64" rings, whereas newer designs are lighter and use 1/16"rings. But it still has its place in the market and high horsepower engines can be made from them. Personally, I would not use them in a higher revving upper class racijng engine today, but they certainly still have their place...
Speed-Pro has actually stopped manufacturing that piston and is revising it. I was engaged in discussions with the product manager at Speed Pro, and one of my suggestions will be incorporated into the new pistons design as agreed upon by their engineers. To get an idea where they are going with the newly deigned dome top, look at their LW2602 flat top (LW=light weight). They will do the same with the Dome top you are inquiring about. Nevertheless, depending on application I would not necessarily overlook the L2443 piston; it's sturdy and rugged...just on the heavy side these days. Evaluate all your options for your motor build and its intended appoication.
I have them in my little ol' jet boat and they work great. 7000+ rpm is no problem whatsoever with them if you have good rods and build your mtor right. 5500-6000 on oem passenger car rods with good bolts should be okay.
If you can get a set with the square cut piston circlip grooves, then opt for the spirolox, I don't have the part number in front of me but will post if tomorrow of you need it.
LO
they are fine..right up until they split in two at the valve reliefs....
[QUOTE=LakesOnly]That piston is an older design from TRW that was originally conceived as an answer to the 97cc D3VE cylinder head...to get compression up. The .030" overbore dome top piston to which you are referring brings the D3VE headed 460 to about 10.66:1 (higher if you shave the heads).
The only primary difference in combustion chamber shape between the early style (D0VE) heads and the late style (D3VE) heads is the depth of the chamber, in that the D3VE head has it's chamber dropped into the cylinder head by another .100". So, those pistons also work in the early style heads quite well and give really great compresion, like 13.2:1.
The L2443-030 dome top piston design has had slight changes over the years since Federal Modul (Speed-Pro) bought TRW in 1995 but is essentially the same configuration.
Piston design overall has come a long way since that piston came out. It is on the heavy side these days and uses 5/64" rings, whereas newer designs are lighter and use 1/16"rings. But it still has its place in the market and high horsepower engines can be made from them. Personally, I would not use them in a higher revving upper class racijng engine today, but they certainly still have their place...
Speed-Pro has actually stopped manufacturing that piston and is revising it. I was engaged in discussions with the product manager at Speed Pro, and one of my suggestions will be incorporated into the new pistons design as agreed upon by their engineers. To get an idea where they are going with the newly deigned dome top, look at their LW2602 flat top (LW=light weight). They will do the same with the Dome top you are inquiring about. Nevertheless, depending on application I would not necessarily overlook the L2443 piston; it's sturdy and rugged...just on the heavy side these days. Evaluate all your options for your motor build and its intended appoication.
I have them in my little ol' jet boat and they work great. 7000+ rpm is no problem whatsoever with them if you have good rods and build your mtor right. 5500-6000 on oem passenger car rods with good bolts should be okay.
If you can get a set with the square cut piston circlip grooves, then opt for the spirolox, I don't have the part number in front of me but will post if tomorrow of you need it
I APPRECIATE THE INFO.I PUT THEM IN THIS YEARS MOTOR,AND JUST HAVEN'T BEEN ON THE NITROUS YET.I USED EAGLE H-BEAM RODS ON EM.HOPEFULLY THEY'LL HOLD THE A 200 SHOT.I DIDN'T HAVE THEM CUT AT ALL.HOPE THAT WASN'T A MISTAKE!CAN'T AFFORD ANOTHER REBULID THIS SUMMER.GOT 3HRS BREAK IN ON IT,GOING TO STICK IT TODAY. :clover:
I APPRECIATE THE INFO.I PUT THEM IN THIS YEARS MOTOR,AND JUST HAVEN'T BEEN ON THE NITROUS YET.I USED EAGLE H-BEAM RODS ON EM.HOPEFULLY THEY'LL HOLD THE A 200 SHOT.I DIDN'T HAVE THEM CUT AT ALL.
Beware that these pistons have little material between the top piston ring and the bottom of the intake valve pocket.
http://www2.***boat.com/image_center...350TRWGood.jpg
That thin area is a potential hot spot and can burn through if you go too lean, so set youself up fat for the first few bursts and do plug readings. Read mixture and also check for peppering.
If you let that potential hot spot reach the point of detonation, your piston may end up looking like this:
http://www2.***boat.com/image_center.../350TRWBad.jpg
In all fairness, the cause of the above piston failure was purley the result of switching to a lesser grade fuel that did not have adequate anti-detonation properties for the application. Still, the piston design itself is not to be overlooked under more extreme circumstances such as yours (nitrous).
The type of failure as pictured above is more common in the BBC pistons due to their increased valve angles (relative to the Ford) and resulting piston crown configurations (this was acknowledged by Speed-Pro). Still, this particular feature in the L2443's design is precisely the topic of discusson I was engaged in with Speed-Pro, and the decision was made to lower the top ring a few thou, as their is penty of room in the ring pack and helps to neutralize the potential hot spot.
Don't go lean with that nitrous.
LO
p.s. Just want to add that the dome can be whacked off so as to lighten the piston and it works great. Don't even have to take the whole dome off. just take of .200", for example, and you will still have maybe 9cc's of dome remaining. (Weigh pistons before and after; 2.8 grams = ~1cc removed from dome.)
Beware that these pistons have little material between the top piston ring and the bottom of the intake valve pocket.
http://www2.***boat.com/image_center...350TRWGood.jpg
That thin area is a potential hot spot and can burn through if you go too lean, so set youself up fat for the first few bursts and do plug readings. Read mixture and also check for peppering.
If you let that potential hot spot reach the point of detonation, your piston may end up looking like this:
http://www2.***boat.com/image_center.../350TRWBad.jpg
In all fairness, the cause of the above piston failure was purley the result of switching to a lesser grade fuel that did not have adequate anti-detonation properties for the application. Still, the piston design itself is not to be overlooked under more extreme circumstances such as yours (nitrous).
The type of failure as pictured above is more common in the BBC pistons due to their increased valve angles (relative to the Ford) and resulting piston crown configurations (this was acknowledged by Speed-Pro). Still, this particular feature in the L2443's design is precisely the topic of discusson I was engaged in with Speed-Pro, and the decision was made to lower the top ring a few thou, as their is penty of room in the ring pack and helps to neutralize the potential hot spot.
Don't go lean with that nitrous.
LO
p.s. Just want to add that the dome can be whacked off so as to lighten the piston and it works great. Don't even have to take the whole dome off. just take of .200", for example, and you will still have maybe 9cc's of dome remaining. (Weigh pistons before and after; 2.8 grams = ~1cc removed from dome.)
going rich with nitruos is just as bad as going lean.
Clarification: I meant "don't let motor go lean while running the nitrous system."
Thanks Sui,
LO
no sweat.....i love the stuff myself,
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