View Full Version : for the Petrol Heads (overboring)
Trailblazin
12-04-2005, 08:48 PM
well been looking around for some oversized pistons for out Trailblazer and have come up with zilch. Then out the blue I thought about the older 4.3L Blazer! This already is a 0.1Litre increase in bore and since the 4.3L V6 was used in MANY applications, I have hope they do have some over sized pistons. So this may be an option for those who do want to over-bore their block. Im doing some more research, but thought I'd give you guys a heads up that there may be an option!! (FINALLLYYY)
tblazed
12-04-2005, 09:04 PM
Not too sure how much you could gain by boring a 4.2 anyway because the iron cylinder liner wall thickness is already pretty thin at 1.5mm.
Trailblazin
12-04-2005, 09:11 PM
I need a bluueprint of our engines!!:duh:
ive read this over though, might be a more affordable way instead of a westers, dnt know if it'll work
http://www.s-10owners.com/forum/printthread.php?t=2207
read the last 3 paragraphs
I think a cheaper and easier solution would be just to call je and have them custom make them.
Are you referring to the TPS sensor? ... If so, don't think it would work on the 4.2L. Our throttle body is electric and the TPS and TPM are integrated into once piece, where the old S10/LS1 Vette's is a cable linkage with a simple TPS at the throttle body. (We're throttle by wire and they're not).
Pretty sure we can't over-bore the cylinder either, since they're aluminum with a sleeve. There isn't a reason for an oversized piston, as they'd just replace a worn liner at rebuild time and not bother having to bore it out and install an oversized piston. :m2:
johnwiz
12-05-2005, 08:49 PM
well been looking around for some oversized pistons for out Trailblazer and have come up with zilch. Then out the blue I thought about the older 4.3L Blazer! This already is a 0.1Litre increase in bore and since the 4.3L V6 was used in MANY applications, I have hope they do have some over sized pistons. So this may be an option for those who do want to over-bore their block. Im doing some more research, but thought I'd give you guys a heads up that there may be an option!! (FINALLLYYY)
Entirely different animals... the 4.3L is a V6 with a 4.0" bore and a 3.48" stroke. The engine was problematic, numerous issues with the EGR valve and the Fuel injection 'spider' (one central fuel injector with 6 poppet valves). The fuel injector and supply lines were prone to develop leaks, causing surging and stalling. It was also a traditional cam in block design with two overhead valves. I had a 93 S-10 with the Vortec 4.3L, spent many hours under the hood of that truck. The engine was basically a 5.7L V8 with two cylinders removed.
The 4.2L is an inline 6 with a Bore of 3.66" and a stroke of 4.01". So there is no way the pistons could be used. Also given that the 4.2L is a DOHC with 4 valves per cylinder, the valve reliefs would be very different..
Just picked up a 2005 SWB Trailblazer.. very impressed with the engine over the 4.3 in my old S-10.. despite have about 800 additional pounds the new TB moves out much better than my old one... Look forward to trying it some snow...
ScarabEpic22
12-06-2005, 01:36 AM
Entirely different animals... the 4.3L is a V6 with a 4.0" bore and a 3.48" stroke. The engine was problematic, numerous issues with the EGR valve and the Fuel injection 'spider' (one central fuel injector with 6 poppet valves). The fuel injector and supply lines were prone to develop leaks, causing surging and stalling. It was also a traditional cam in block design with two overhead valves. I had a 93 S-10 with the Vortec 4.3L, spent many hours under the hood of that truck. The engine was basically a 5.7L V8 with two cylinders removed.
The 4.2L is an inline 6 with a Bore of 3.66" and a stroke of 4.01". So there is no way the pistons could be used. Also given that the 4.2L is a DOHC with 4 valves per cylinder, the valve reliefs would be very different..
Just picked up a 2005 SWB Trailblazer.. very impressed with the engine over the 4.3 in my old S-10.. despite have about 800 additional pounds the new TB moves out much better than my old one... Look forward to trying it some snow...
Welcome to the site!
I noticed the exact same thing when I got my TB. Sold a 96 Jimmy for it, and it does everything much better than the Jimmy, towing, comfort, performance, absolutely everything.
DouglasEsh
12-06-2005, 06:09 PM
Welcome to the site!
I noticed the exact same thing when I got my TB. Sold a 96 Jimmy for it, and it does everything much better than the Jimmy, towing, comfort, performance, absolutely everything.
Yea, but I miss having a pickup bed. I could put a bunch of stuff in the back of my old S-10.