BIG BLOCKS !!!!!!

[738 driver]

Anyone ever considered or run an alloy block, big-block Chevy in the Ultima?

Seemingly they turn high rpm much easier/more reliably and obviously produce tons of power too.

Just a thought for the future!!!

[Steve_D]

They don't fit.

Steve

[738 driver]

Dimensionally or in what respect ??

[Steve_D]

I believe they are too long which would in turn put the 'box further back making the drive shaft angle to severe.

Steve

[738 driver]

Hmm.... the big-block is only about 100mm longer, not the end of the world but a fair bit of juggling to do.
Anyhow, just thinking 'outside the box'...... maybe for the future, who knows???

Thanks for the response.

[qwick]

They're also a lot heavier, I didn't think that they revved as well as a small block. An interesting thing to do might be to bore and stroke a small block to big block capacity... Having said that there's a a few 6+ litre SBC's out there and if you want 7 litres why not use a alloy block LS7?

[738 driver]

Qwick,

I was referring to an alloy block/head version ( lighter than iron SBC's)

I too thought that SBC's would be easier revving but seemingly the big blocks are much happier and live longer at higher revs (8000-9000).

Plus, the higher power levels (700-800hp) are far easier, cheaper and less risky goals !!!

Surely worth some consideration in the future ???

[CarMad426]

I seem to remember that there was an Ultima with a Big Block in it if i remember correctly. Cant think of who it was though.

[jschwartz]

Fit is very tight.
With 730 hp pump gas 7.0 L small block LS7's available, which weigh in at 390lbs dressed, no need for a boat anchor (even alloy) Big block chevy. And LS7 is cheaper too! To compare, Price out a dry sump, Ti valved, alloy block, EFI Big Block Chevy.
Jeff Schwartz

Edited by jschwartz on Thursday 3rd July 04:02

[GTRCLIVE]

390lbs is that right..... wow didn't realise they where that light.... Happy Days..

[chuntington101]

with the LSx engine you can push them as far a 500cubic inch! SBC are a little smaller, the biggest normally being 454. or you could go with a biliet block and have whatever you wanted! lol

realisticly though, the LS7 is a stonking engine! if you want big N/A power then this is a very good starting point!

Chris.

[crafty]

... Chris... you managed to suggest an engine without twin turbos. Are you feeling OK today?

[GTWayne]

Installation issues aside, why on earth would you want a BB in an Ultima?
The Audi engine is getting a fair bit of attention these days and although I can see the sense with regards to using this motor, I do feel that it is a little understated. A BB on the other hand is overkill as far as I am concerned; More heat, more weight ( the motor actually weighs more like 550lbs! ), transmission torque handling problems and the thing that EVERYONE seems to overlook, YOU DO NOT NEED LOADS OF POWER IN THESE CARS, END OF!
I can not guarantee this as a recipe for success but it works for me, the ingredients are;

1 X Ultima kit
1 X 5/600bhp SBC/LS motor with dry sump and injection
1 X gearbox with LSD and a modified/specd. set of ratios
1 X set of decent tyres although the choice is limited I know

[chuntington101]

crafty said:

... Chris... you managed to suggest an engine without twin turbos. Are you feeling OK today?

i do feel a bit off crafty lol

[738 driver]

So, it would physically fit.
Cheers for all the additional input.

Fully agree that if you want instant turnkey power , the LS7 is the way to go these days.

However, thats not for me, neither are turbo's, superchargers or NOS. I'm with the sad and boring 'old school' cam, heads and carb route (maybe with a bit of electronic injection thrown in every now and then).
Already having taken on board the feedback and experiences from the likes of Steve and Can-Am Dave' my initial Small Block build has been heavily modified. The former big cube torque monster has been re-jigged into a revvy short stroke. But to achieve this on a normally aspirated pushrod motor will reduce the valvetrain's life considerably, hence why people go the supercharger/ turbo route.
So.... not for this first Ultima engine which I'm sure will be plenty to play with initially, I started to think and research how to produce a naturally aspirated, good output (650-750hp), high revving, longer living engine.
The conclusion being, on a reasonable budget ($12-14000 in parts), a simple alloy block and headed big block chevy.
All the US chevy engine gurus confirm and agree that a short stroke big block will happily sit at 8000rpm many times longer than a similar small block. The larger valve gear is more up to it!

The weight problems dont exist as an all alloy BBC with lightweight internals is marginally lighter than the all iron sbc originally fitted to the car.

So really its mainly down to transmission/traction issues........again!!

[chuntington101]

738 driver said:

Hmm.... the big-block is only about 100mm longer, not the end of the world but a fair bit of juggling to do.
Anyhow, just thinking 'outside the box'...... maybe for the future, who knows???

Thanks for the response.

is the DDB really inly 100mm longer?? if so then it might fit length wise. Stig had to mount his engine 2inch further back then normal to get the superchager sount to, sort of, clear the bulk head. also whats the length of the waterpump assembly on the SBC?? could this not be removed and replaced by an electric remote mounted one or even two??? you would still have the alternator to drive. i ahve seen race cars that drive them off the drive shats. could this be done?? could you mount two (thinking that two water pumps are going to be a BIG draw on current when they are at full power)??

just thinking

Chris.