How much power does a blue 253 have stock?

[JD]

as the title says, how much power do they have??

[V85000i]

around the 100kw mark.

[JD]

know an exact figure?
i thought it was around there but i would like exact specs if possible.

[SL/ENUT]

100kW with single exhaust(at 4200rpm), 115kW with dual exhaust(at 4400rpm)

[V85000i]

Holden Blue 4.2L V8
Capacity: 4.2L
Induction: carburetor (Quadrajet 4-barrel)
Valvetrain: overhead valves, 2 valves / cylinder
Bore x Stroke (mm): 92.075 x 77.775
Compression Ratio: 9.0:1
Maximum Power: 100kW @ 4200rpm with standard single exhaust, 115kW @ 4400rpm with twin exhaust option
Maximum Torque: 269Nm @ 2000rpm with standard single exhaust, 289Nm @ 3200rpm with twin exhaust option

[JD]

thanks to the both of you, helped me out heaps, just one final question 2.5" straight through single would make a gain of what?

[253@7k]

Well, new condition 100kw but with the age of a blue 253 maybe now around 85/90? And a single exh around +4/5kw

[JD]

engines only done 30k since rebuilt so it should be pretty close to 100kw, thanks slundy!

[vh_v8]

see if you can grab one of the holden option dual exhausts. i got one for about $100, made it sound a bit better and there was a noticable power increase. only problem is you move you peak torque up 1200rpm and that is especially noticable if you have a 2.78 diff.
if you were to get extractors and join them to the twin pipes youd get a bit more power there too.

[JD]

how do you think it would sound if i got the extractors on the 2.5" single system i have now?

mines doesn't really sound beasty until you hit 4 grand
but ive driven kingswood 253's that sound killer stock!

[253@7k]

That would be a good set up mate, grap some tri-y's they are good for low down power and are reasonably cheap. I run tri-y's into twin 2.5 inch pipes with straight through mufflers on my z and ive got an awsome note right up to the rev limiter at 7k.

[JD]

sweet, cheers slundy and btw 253's go up to 7grand!?!
i dont take mine past 5500 as per tacho redline.

[253@7k]

sweet, cheers slundy and btw 253's go up to 7grand!?!
i dont take mine past 5500 as per tacho redline.

well mine does with a little work to it im making power till 6600. 253's rev hard you just have to get the right bits on them.

[JD]

what work have u done?

[253@7k]

The engine was rebuilt (from what ive been told) with acl race series flat tops and acl bearings and arp bolts (but otherwise stock) before i got it, ive cleaned up the heads with new valve springs (no major porting), cam (216/226 @ .050 with 112 deg lobe seperation) double row t/chain, single plane manifold (ported and polished), 600 holley with braided fuel lines and h/v fuel pump, jp oil pump, gilmer drives, twin thermos, msd pro billet dizzy/msd 6al ignition/msd coil with custom leads. i think thats it..... with a toyota 5 speed and 3.08 lsd.

600 will be going soon for a 465. 600 is only good in the upper revs, no good down low.

[253@7k]

its quicker than most 304 commodores neways so its gotta be making a bit of power.

[JD]

sounds like it! good job!

[253@7k]

The cam change was the best mod ive done. it is far easier than you would think plus it gave me heaps more power, a way way nicer exhaust note and idle and would you belive much better economy. it ended up costing me around $500 so not that expensive either.

[JD]

thats what i was planning on next, that and extractors. and rego

[253@7k]

Yeah thats a good idea mate. hold off on the cam if your trying to get it licenced, they dont like cars that wont idle......

[JD]

nah just gotta get it registered ran out 2 months ago and atm i have a serious cash flow problem