building high comp 253

[VR38]

Give me a mild cammed small headed 4bbl 253 VB/C etc anyday over a stock vnv6
Sounds like A LOT of people don't have a clue and are compensating with 55 extra cubes on their 308's...

 

[EYY]

Give me a mild cammed small headed 4bbl 253 VB/C etc anyday over a stock vnv6
Sounds like A LOT of people don't have a clue and are compensating with 55 extra cubes on their 308's...

I hope this isn't aimed at me.

Don't get me wrong, I've had a 253 and would happily have another - they sound cool and are incredibly reliable. I like the character of the older holden and that's why I still drive old/'outdated' cars.

But from a dollar per hp standpoint if you're going to spend up on an old Holden V8, you'll alway be ahead with the 308. But that's not what this thread's about anyway.

Personally, I'd much rather see a 253 in the engine bay of an early holden than an LS*.

 

[VR38]

JMHO

IF something is directed it is usually quoted.

Just saying, all those 253 Brock/HDT Commodores must be shite and worthless than a V6 VN these days, If anyone has one and wants to swap then LMK.
The first HDT was 253 but what would those fools know...

 

[gtrboyy]

Doesn't matter if 202/253/304/308 they all have low compression with factory pistons.

To get most out of any of them for cam change to be worthwhile usually means flat tops.

Then when look at budget or bang for bucks can see why most go largest cubes 'cos it cost same & easier hp/torque.

Find a good 2nd 253 someone has put flat tops in & take advantage of their loss.

 

[VR38]

Agree, flattops are a must for any 25308 build...

 

[EYY]

Low comp 253's have flat tops standard. High comp 253's have raised crowns.

Still, the early engines had smaller combustion chambers and higher static compression. Along with the introduction of ULP and more stringent emissions requirements came lower compression (larger combustion chambers).

That's from the factory though, good luck finding an old holden engine as it came from the factory for sale.

 

[gtrboyy]

They're still low compression from factory with pistons down the bore.

You'd want mid 9's to get more out of a cam change not mid-high 8's

 

[harrop.senator]

Weren't pre emissions close to 10 static with 280 adv cams in leaded day or wives tales?

 

[gtrboyy]

Never really been what we consider high comp more like high 8's with decent drop down down bores from deck height.

vn group a with flat tops barely 9:1

Earlier engines with dished casties...

 

[Zeke Topanaga]

Most V8 owners will tell you to ditch the 253 because it lacks the capacity to give any real performance but in a smaller car like the VH, it could be quite a reasonable performer. You said you only wanted a cruiser, not a bruiser, so with sensible mods you can make it just what you want.

At least in the VH, you finally scored a four barrel. Should have been there from the start. Years ago I had a 253 HG GTS manual. The only mods were dual pipes and a Holley 350 two barrel carb. The Monaro was a heavy car, yet it could keep up with a mate's 308 HQ van and beat another mate's 308 Premier wagon with a single exhaust system. And that was just a red 253. It convinced me that little motor had something to offer and I laugh when others ****-can it because it's too small.

I agree with you that is true, them old HT-G-Q 253 could go well back in the day for what they were, I had a HG Premier auto 2.78 ratio diff and just a free flowing single 2 1/4 exhaust and it ran neck to neck with a XB351 2BBL auto with twin exhaust and a stock XC 5.8L auto with twin exhaust, I had many runs with them all the way to 110mph and it was neck and neck all the way.
From the HJ 253 on they got a smaller cam.
350 Holley is a good carb for a 253.