XR6T 1900rwhp rumour?

[Rz]

looks like toyota where a bit more savvy with packaging , then old mate at ford.
a four litre six shouldnt be that much longer then a 3l.
advantages in shorter hence stiffer crank , and better weight distrubition for the car its going in.

[The Pupat]

looks like toyota where a bit more savvy with packaging , then old mate at ford.
a four litre six shouldnt be that much longer then a 3l.
advantages in shorter hence stiffer crank , and better weight distrubition for the car its going in.

Guess that's what happens when you build an engine 10 years later and a design size of 2.5L, given Toyo naming 1JZ would be first generation hence original size was 2.5L then bored and stroked to 3L

Unlike the Barra that started life as a 4L in the 70's, or was it the 60's.

[Greg Rust]

Yep Falcon shares the same bore spacings as the first 200ci back in the 60's

[Billzilla]

looks like toyota where a bit more savvy with packaging , then old mate at ford.
a four litre six shouldnt be that much longer then a 3l.
advantages in shorter hence stiffer crank , and better weight distrubition for the car its going in.

I suspect the JZ's use a siamesed bore and the Ford's use a full-flow bore and that makes the block longer but you get better and more even cooling around the bores that way. Slightly better ring sealing as well.

[Rz]

current ford donk would only share bore spacing with its predecessors surely ?
so they had a clean sheet to play with when they went dohc , other than wanting to use the same crank blanks.

[Billzilla]

I guess they figured it all worked okay before, no need to change it especially as they were making an engine of the same capacity.

[Rz]

hmm interesting.
be good if someone so equipped , like GAS , could do a engine dyno shootout to destruction , xr6t vs 2jz , both grouted/built/gt55's
id fly down to watch that happen

[GSRman]

[data_mine]

current ford donk would only share bore spacing with its predecessors surely ?
so they had a clean sheet to play with when they went dohc , other than wanting to use the same crank blanks.

And that's pretty much it.

Considering it started out with a in-block cam (OHV) and non cross flow head. moved to a cross flow head (XC), alloy crossflow, then SOHC (EA), then SOHC with VCT (AU), and now DOHC (with various VCT options along the way, started off being stepped intake only BA, through to BF with fully variable intake and exhaust).

The block and heads are very much different to what was started with. As said, other than general dimensions of bore and spacing.

[9triton]

Yep Falcon shares the same bore spacings as the first 200ci back in the 60's
.

yeah - was at ford for the 50th falcon anniversary and chatted to some ford dude - said that the bore spacing was still same as 1960 ford 6 falcon engine

[Momus]

On a well developed engine horse power potential is governed by intake valve area and flow.The intake valve area is closely related to the bore size, not the overall capacity of the engine.

The std Ford engine has a 92 mm bore, the std Toyota 86 mm; about 7% bigger. In an optimised engine the Ford would have proportionately larger valves because there is more room to fit them. So, based on this rule the peak horse power potential of the Ford at any given pressure would be about 7% greater. If the Toyota engine running 5 Bar absolute is making 2000 hp then the Ford would make 7% more say 2140 despite its 33% bigger capacity.

This is not the full story because the optimised bigger engine will have higher average horsepower and be able to accelerate the car faster for the same peak.

It's a bit hard to tell from the photo, but the Ford head doesn't look as good as the Toyota's. It seems to have a shallower, flatter entry angle which is usually an indicator of lower efficiency.

The Ford head is longer, but no deeper, so possibly not as mechanically stiff to resist combustion and engine block twisting loads.

The Ford crank is obviously a lot longer as well as having a 13 mm longer stroke than the std 2j. Some challenges there if it is to operate at the necessary 8K or so rpm required

[Momus]

Yep Falcon shares the same bore spacings as the first 200ci back in the 60's

Which was a development of a Ford of Canada tractor engine...from the 50's

They share main bearing bulkheads in the same position as well.

[2JZR31]

The std Ford engine has a 92 mm bore, the std Toyota 86 mm; about 7% bigger.

92mm = 6647mm2

86mm = 5808mm2

Diameter might be 7% but the area is more like 15%. And that is before it is re sleeved to be bigger. Huge bore spacing suggests it can be a lot bigger than what it is. Can any engine builders comment on this?

[gmh265]

I agree, Ive spent much time trying to get much lower power'd cars than that to work on a Dyno. Hub dynos are not rated anything like that hi so it must be a chassis dyno so that just crap.
Ive seen a Summernats Hero engine 1st hand on an Engine Dyno make about 800hp less than it makes on the wheels at Summernats.

Assuming it was not done on an engine dyno?

[9triton]

Which was a development of a Ford of Canada tractor engine...from the 50's

They share main bearing bulkheads in the same position as well.

FYI the first ford 6 cyl 200ci engines (ie falcons )were only 4 main bearings engines- (approx 1963/1964 ) as were a over bore and stroke of the 144 /170ci engines ( 4 main bearings)



changed to 7 mains approx 1965/1966 (maybe a year earlier in teh USA)