Outer Limits 4x4 Board

Has anyone had any experience with the 1750 big bore kit available for the 1600 8v. Am considering this for my 1600 8v sierra.

Would it be worth it to increase performance?

probably better to go EFI...

going by the old saying...........
"no substitute for cubic inches !!"

if thats wat you want ....GO FOR IT !!!

(then go EFI as well !! )

I had a little think about this big bore kit - in terms of value for money...

As a simple guesstimate, lets say you are increasing a 1600 to 1800 = 200cc = 12.5%

so if we said that a 1600 makes 70kw (EFI model), then you might guestimate that you would get 12.5% = 8.75kw...

I don't know - has anyone actually seen some figures for these over-bore kits?

The suzi-sport version is $1750, which, if you were starting with a 1.3L carby engine and upping it to approx 78.75kw - then awesome... but for 70 to 78.5kw, it sounds like a lot of coin...

The suzi-sport mod also appears to be only for the 8v engine - can it be done with the 16v EFI model?

blocks are the same arnt they?

also i bought my 1.6mpfi frontcut for $1600 (food for thought)

greg wrote:I had a little think about this big bore kit - in terms of value for money...

As a simple guesstimate, lets say you are increasing a 1600 to 1800 = 200cc = 12.5%

so if we said that a 1600 makes 70kw (EFI model), then you might guestimate that you would get 12.5% = 8.75kw...

I don't know - has anyone actually seen some figures for these over-bore kits?

The suzi-sport version is $1750, which, if you were starting with a 1.3L carby engine and upping it to approx 78.75kw - then awesome... but for 70 to 78.5kw, it sounds like a lot of coin...

The suzi-sport mod also appears to be only for the 8v engine - can it be done with the 16v EFI model?

Not all about kw's, must be a descent increase in torque from the extra cubes.

Dan

JrZook wrote:

greg wrote:I had a little think about this big bore kit - in terms of value for money...

As a simple guesstimate, lets say you are increasing a 1600 to 1800 = 200cc = 12.5%

so if we said that a 1600 makes 70kw (EFI model), then you might guestimate that you would get 12.5% = 8.75kw...

I don't know - has anyone actually seen some figures for these over-bore kits?

The suzi-sport version is $1750, which, if you were starting with a 1.3L carby engine and upping it to approx 78.75kw - then awesome... but for 70 to 78.5kw, it sounds like a lot of coin...

The suzi-sport mod also appears to be only for the 8v engine - can it be done with the 16v EFI model?

Not all about kw's, must be a descent increase in torque from the extra cubes.
still choking on the same cylnder head dont forget 8v heads arent exactly the best flowing head with a 1600cc i imagine it will only choke on itself without major head work, Plus you need to consider the factory carby wasn't designed to flow the amount of air required for a 1750cc engine. I'ed be spending my money on a efi 1600 16v, better throttle response, better fuel econimy, won't stall climbing steep hills and my bet is more power too!!!
Dan

your still choking on the same cylnder head dont forget 8v heads arent exactly the best flowing head with a 1600cc i imagine it will only choke on itself without major head work, Plus you need to consider the factory carby wasn't designed to flow the amount of air required for a 1750cc engine. I'ed be spending my money on a efi 1600 16v, better throttle response, better fuel econimy, won't stall climbing steep hills and my bet is more power too!!!

my 1600 8v with the weber on it oozes power compared to the 1.3 i had in before it... but im tired of carbies and want to go EFI for power and the fact i can run a snorkel off it (i cant with the weber cos its too tall).

cut a hole in ya bonnet then, mmm weber lol
Anyway the bigbore question was brought up awhile back with someone saying no dont do it and hinted they had a good reason (not $ or power either) and Ive searched before and never found reports on it.
I think??? Pagey may have run one in his red swb??
Nik

greg wrote:
so if we said that a 1600 makes 70kw (EFI model), then you might guestimate that you would get 12.5% = 8.75kw...

I don't know - has anyone actually seen some figures for these over-bore kits?

The suzi-sport version is $1750, which, if you were starting with a 1.3L carby engine and upping it to approx 78.75kw - then awesome... but for 70 to 78.5kw, it sounds like a lot of coin...

The suzi-sport mod also appears to be only for the 8v engine - can it be done with the 16v EFI model?

If sould be done with the efi motor, it would create an interference motor I imagne, and then you'd need to retune the ecu for the larger capacity. I think it would be a VERY expensive way to gain a very small increase in torque/power.

I also remember hearing that the way these were assembled didn't result in a very durable motor, but don't recall the details.

Steve.

Gwagensteve wrote:If sould be done with the efi motor, it would create an interference motor I imagne, and then you'd need to retune the ecu for the larger capacity. I think it would be a VERY expensive way to gain a very small increase in torque/power.

Oh i agree - sorry - this was what i was trying to say also...

The suzi sport block is 1750 (still need to fit it yourself), add 1300 for a unichip (inc fitting and dyno time)... and you end up with $3050 for approx 12kw...

Jr Zook - you're right - torque should be increased... guestimating that figure would come in about half way between the G16EFI and J20A (based on cc's - not engine design) so i guess it could be as much as 156nm... (i.e. 18nm increase on the G16EFI)..

the reports on the durability would of been from me , although for the life of me i cannot find the post .

the problem with the 1750 is this ...

you are boring a 75mm bore out to 78mm , the sleeves get very thin , it also requires a custom made head gasket that are about $150 a pop . once a rebuild is required if the bores are unserviceable , its new block time , theres no overboring and oversize pistons , because the sleeves have already been bored to their maximum (if not more) than what they can be overbored. its hard enough to source a good g16 block as it is without getting one then having to get machine work done to make the mazda pistons fit

when i was doing this conversion , was seeing the same cars back again and again with blown head gaskets between the cylinders .

in hindsight , a remedy to the problem , would be to 'o' ring the block (another $250) this could of possibly stopped the head gasket issues associated with this particular engine.


for value for money and reliability , id have to go with others who have said mpfi 1600 , just change your pistons and put the efi cylinder head and management on ,efi fuel pump , you will be miles ahead of a 1750 carby engine . probably wont cost as much either.

to me , if you already have a 1600 , and you spend over 2000+ to do the 1750 conversion you will be sadly dissapointed , and will still ultimately have a shitty carburettor.