47 replies to this topic

[RIM-010]

I thought that 253's and 308's ran the same manifold from factory...

Any particular reason why you don't want a 308?

Tim

Edited by RIM-010, 30 August 2008 - 11:37 PM.

[RIM-010]

I forget things sometimes...

Tim

[Collo]

Dunno if its right but someone (cant remember who) told me that one of the early commodore models was the only one to come out with a 4 barrel manifold on a 253.

[Collo]

Yeah who knows. alot of oddities on the old cars from the factory.
Engine no. prefix will tell you what model the motors from.

Swappin manifolds isnt hard and probably common to replace the 2 barrel with a four on a 253.

[TerrA LX]

Basically everything you do to a 308, a 253 responds the same, even better if you keep the valves/ports to a suitable size.

[rodomo]

VC & VH Commodore 253 (4.2) came factory with 4bbl Rochester.
You can make them go.
I will be putting one in the Bombadoor within the next 12 months.
RRS might have pull his socks up

[fuzzypumper]

All 308s had 4 barrells. I believe it was the Blue motor 253's( VC commodore) that had 4 barrel Rochesters from the factory, all the Red motors came with the 2 barrel strombergs (HQ, HJ, HX, HZ & VB commodore) AFAIK. Once the VK commodore came along the 253 was dropped and only black 308s where built. Correct me if I'm wrong anyone.

In any case, assuming your rebuilt 253 has was done correctly and still has at least the 9.0 to 1 compression ratio, Im sure it will benifit from some head work and a mild cam. Just dont over size the head valves. At least with manual you wont have worry or spend money on a stall converter.

[rodomo]

Once the VK commodore came along the 253 was dropped and only black 308s where built. Correct me if I'm wrong anyone.

Correct AFAIK

[TerrA LX]

All 308s had 4 barrells.

No not ALL 308's had them, some had the two barrel set up same as 253.

[GML-31]

there was an article in engine section about getting 330hp out of one but images are down, I did a PDF of it fortunately so if you want to read it I will email to you.

[yel327]

No not ALL 308's had them, some had the two barrel set up same as 253.

Yes there was one and only 308 with a 2 barrel, but it wasn't a WW Stromberg it was a 2 barrel Rochester like a HK/T 307 but fitted with a governer. It was a V coded engine (ie xV instead of xT) low compression engine in an M series Bedford. The rest were all 4 barrels. All VC-VH and WB 253's were also 4 barrel.

To make a 253 go good a 4 barrel and Quadrajet, HEI dizzy off a blue motor, extractors, mild cam and stock valve heads. You can do more but it's be cheaper to build a 308 than go any further.

Edited by yel327, 31 August 2008 - 10:07 AM.

[MRLXSS]

You can build up a 253 to have a fair bit of go. What TJ put up would get you a good amount of power... But that would mean pulling the engine out and if you do that, you might as well put in a 308...

If you just want cheap things to improve power and stuff.

Get some good Quality extractors and get a twin system (Twin 2.25" is good for a 253)

Put in an Electronic Dizzy (Make sure you have 12V at the coil)

Maybe get some Thermo Fans and loose the big engine fan

Then once all that is donem GET IT DYNO TUNED! A tune will be the best thing you do, a good tuner will get the carby working great and really responsive! Make sure you do the tune after you have done everything though.


Other things you could look at doing, is a Cam and Maybe getting bigger valves in the heads and a bit of port work, also higher compression would do wonders for you!

[makka]

you need the 3 C's

Carb

Cam

Compression

You already have the base there with the 4 barrel manifold, Rochester and extractors, now just get the heads tidied up, bump the compression up and fit a bigger cam. An electronic dizzy helps too

[fuzzypumper]

I reckon MRLXSS & VEL327 pretty much got it right.

In your situation, as the motor was rebuilt recently and you seem possibly reluctant to redo the bottom end, so really only leaves you with hand full off bolt on addons you can do. Any more than that will be of no benefit on a 253 without raising your compression.
As mentioned earlier, if your gonna go to the trouble of putting in new pistions for at least 10to1 compression you may as well spend the money and time on a 308.

As suggested , thermo fans, electronic dizzy, exhaust, good extractors and a mild camshaft( maybe some HD valve springs too)are all good easy beneficial addons and wouldnt even have to pull off the heads off or motor apart.
You already have the 4 barrel carb which is good for 1.5sec better on the quarter mile than the 2 barrell.