Doing up a 173 blue motor??

[frenchyvh]

Gday fellas,
posted comments earlier about whether i could or couldnt put an older holden 6 in my commy or whether it was worth doing up the 173...I'm leaning more towards doing up the existing 173, has anybody done this? i'm also interested to know, realistically, how many CI's I'm able to bore this head out too? If anyone could help me i'd much appreciate it,
Cheers, Rhys

[DANNY8]

I have a blue 173 that im rebuilding.....getting it bored out to fit 186 pistons in. I believe the 173 and 202 are the same blocks, so I'd say maybe 60thou over wat 202 specs are, any bigger and u might not be able to get pistons for it. I aint an expert tho so I could be wrong.

[1vngal]

The best 173 I've ever seen done up was in a torana. Bored out to 192, bigger cam and straight cut timing gears (Ohhh...I love the sound of those...) And talk about power. It was nuts!!

Is yours auto or manual? That motor with the 5 speed, was pure pleasure to drive.

[frenchyvh]

mine has a 5 speed in it, looking to convert it to a supra or t5 box soon, going to get the 173 sorted first...so i can get the 173 bored out to a 192?? Can anyone confirm this???

[atrail308]

i thought it was only the red HP blocks that could go out to 192 due to being a stronger casting...

[frenchyvh]

i thought it was only the red HP blocks that could go out to 192 due to being a stronger casting...

If that's the case then does anyone have an idea on how much i can bore the motor out before i start having problems?? The old man's mechanic doesn't know alot about the holden 6's so i'm having to try and get info on them elsewhere, so any help would be much appreciated..

[Matty081]

i thought it was only the red HP blocks that could go out to 192 due to being a stronger casting...

to my knowledge they are all the same. Then again, i'd never heard of a blue 173.
I imagine the only difference would be the water jackets. and extra holes in the block.

ask the guys on oldholden.com

[SL/ENUT]

i thought it was only the red HP blocks that could go out to 192 due to being a stronger casting...

Thats 179 ci motors, the 173 are a different motor.
I can't see why boring out a 173 -192 wouldn't hurt it, you can do the same to the ole 186 as well.

[vk3800]

Found this chart while finding out about the 173, might help clear up some things on straight 6 engine sizes.

http://users.mrbean.net.au/~rover/choosing.htm

[atrail308]

yeah, the HP's were 179's and 186's, depending on the model they were released in, as for the 173, it may be that the different water jackets cause it to have a thinner cylinder wall, therefore cant be bored out as much...

[vk3800]

some one delete this
posted the same thing twice

[1vngal]

Well, dunno how strong it was or anything, but it was definately 173 bored out to 192. So it's definately possible.

[5Litre]

Never built a 173 but had heaps of 186's and what you need to consider is how much extra power you get from a few extra ci's , not bloody much i can tell ya.
boring out 60 thou will get you about 6 ci extra ie 179 .
better to only bore it what it needs , if it can't just get away with a hone. Pistons shouldn't be hard to find in a range of sizes. If you really want more cubes buy a 202. It'll probably be cheaper than machine work on the 173.

[atrail308]

the more you bore it out for those few extra cubes, the hotter it runs...

[tigervh]

The most you can safely bore any Holden six is 60 thou, 80 thou pistons were available some years back but!!!. Considering a 173 block has a bore of 3.5" and a 186/202 is 3.625, thats a difference of 125 thou, you're simply too close to water. If you're planning to spend serious money on a Holden six, you'd be much better of getting your hands on a blue or black 202, these motors came out with a fully counter-weighted crank and the Starfire/XU1 heavy duty rods. You can pick up a rebuilder up from the wreckers for bugger all dollars these days. Remember the cost of the core is only a fraction of the finished cost of the motor.

[Goon]

If you do come across a blue / black 202, it would be best. just as in idea ! to see it running first and see what it sounds like... even if its in a rust bucket, you just want the motor ! so after you've done the rebuild you can see and hear the improvements

[Dan355]

While your there get it stroked to

[tigervh]

Well, dunno how strong it was or anything, but it was definately 173 bored out to 192. So it's definately possible.

You must be mistaken, a 186 bored .060" will produce 192cu in, to take a 173 that far you would have to take it out 0.185 oversize!!!, approximatley 3 times the boring limits. Each different capacity in the L6 engines had its own own unique core, hence you can't just bore one size out to another. The only two engine sizes that shared the same bore size were the 202 and the 186, but the 202 uses larger main bearing diametres, so not even those two block are interchangable. As I've said before, the boring limits for all L6 engines is .060"

[atrail308]

The most you can safely bore any Holden six is 60 thou, 80 thou pistons were available some years back but!!!. Considering a 173 block has a bore of 3.5" and a 186/202 is 3.625, thats a difference of 125 thou, you're simply too close to water. If you're planning to spend serious money on a Holden six, you'd be much better of getting your hands on a blue or black 202, these motors came out with a fully counter-weighted crank and the Starfire/XU1 heavy duty rods. You can pick up a rebuilder up from the wreckers for bugger all dollars these days. Remember the cost of the core is only a fraction of the finished cost of the motor.

True that the 173 cant be bored that far, niether can the stock 179 or 186 without problems, the only ones to safely bore are the 179/186 HP blocks...
As for the blue/black 202's, the blue one had counter-weight crank and XU1 style rods, but the black one used a steel counter-wieght crank but only old style stock red motor rods, i guess holden were just using up their old leftover parts... Niether had starfire rods, which were even stronger than the XU1 rods, but can be fitter to either...

[vc6banger]

hey im new 2 this foram but have had abita 2 do with holden 6s over the years i 2 have a blue 2.8 im playin round with at present if u wanna make it 192 use a 3.3 blue or black crank in the 2.8 block 2.8 rods and pistons 40 thou over should b 191.5 ci and 60thou would b 193.5 hope this helps also stanard bore (2.8) with 3.3 crank should b 187.5 ci

[ari666]

thats cool, welcome to forums.

this thread is now 4 years old. so yeah. got pics of your ride or something?