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Username Post: engine upgrade or replacement for 4.3L CPI?        (Topic#347924)
MuddiGGer25 
Contributor
Posts: 192

Age: 27
Loc: Fargo ND
Reg: 01-25-16
10-28-17 08:57 PM - Post#2712511    

So I was wondering what i can do to get more giddyup in my 1994 gmc jimmy (t15) its got the 4.3L CPI currently and yes does its job and runs good, but i was wondering what could i drop in there, but be a bit different from everyone else putting in 3.8's and 350's.


What all engines will physically bolt onto the 4l60e? i have been reading that with a few sensors, and some flashing the PCM could be used to just run the trans if i put a carb on the 4.3l and a more aggresive cam? not sure how well those early vortec heads flowed, not trying to make monster HP (as usual lol) im perfectly happy with monster torque off the line as long as it wont fall on its face until 4000rpm or after.

i know this comes to my next dilemna, its been hard to pin down a "sure" stock power handling # for the 4L60E but it seems that it should be able to handle 320-360ft-lbs from various sites and threads. it can take a pounding from my wifes 350 but thats only 300 ftlbs of tq at something 2800RPM.

I mean if i could get the 4.3l to put out 300-360ft-lbs i am sure i would be happy with that, but i also know that would require a Carb to TBI adapter, a TPS sensor for sure, and flashing the PCM because its not gonna like an aggresive cam lol


ive done searches but most posts everyone just says drop in the 350 for the tq, or put a 3.8l for more economy, or the typhoon/cyclone 4.3l, i havent really found a good post (yet) on building up the 4.3l with just maybe a cam (and intake?)

1994 T15 Jimmy 4.3LCPI/4L60E 170K 3.42s (DD)
1988 V20 Suburban W/1995 454TBI(32PSI)/4L80E/NP241 CA truck, 125K G80 14SF/ GM10 4.10's
1995 K1500 ECSB 5.7 TBI/4L60E, 3.73s 269K(wifes)
1996 K3500 ECLB DRW 6.5L TD 3.73's 198K (new project)



Edited by MuddiGGer25 on 10-28-17 09:02 PM. Reason for edit: No reason given.

 
gchemist 
Senior Chevytalk Moderator
Posts: 24323
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
10-29-17 04:08 AM - Post#2712524    
    In response to MuddiGGer25

CPI was very limited in power. '95 made the most HP @195. Even the MPFI made 190 HP. MPFI vehicles could be adapted to run 4.8 and 5.3 engines while maintaining some stock PCM functions.

Headers, high flow cat, high flow muffler, and bigger/more air flow all help. Removing the upper intake and polishing the inside would help.

Bolt on upgrades are not widely available. It was a limited run engine combo. You have to completely upgrade to get power. Or you can try some NOx!!


Mine is worse than yours. Mine is a rare 3.08 rear end. One of ~3000 made in '95. It gets 18 MPG in the city. Ran up to 24 MPG one trip. A new trans and better converter helped too.

'95 Jimmy SLT (Bought @131,814)
'83 Silverardo XST - ZZ4 powered
'96 GMC Jimmy LS Ret. @236651 miles


 
MuddiGGer25 
Contributor
Posts: 192

Age: 27
Loc: Fargo ND
Reg: 01-25-16
10-29-17 09:19 AM - Post#2712543    
    In response to gchemist

I know its limited in power but what about as i was saying, switch to carb, a cam with .500 lift (ive read the 94+ cant do over .500 lift stock) and SLA around 110, i want the power band low, and a little loss of idle vacuum isnt the end of the world if im using a carb and flash the PCM


This is what ive been able to dig up so far on the stock cam specs:

CPI cam specs;
'92-'95, Vin W, w/ balance shaft
- Lift (I/E) - .432/.440
- Dur @ .050 (I/E) - .208/.208

tbi CAM SPECS;
'93-'95, VIN Z, w/ balance shaft
- Lift (I/E) - .376/.402
- Dur @ .050 (I/E) - .183/.193

syt cam specs;
'91-'93, ZR9/Z79, Syclone/Typhoon
- Lift (I/E) - .351/.386
- Dur @ .050 (I/E) - .179/.195 (Ductile)


Also reading here, (i know this is just a computer SIM, and real world probably wont be that close): http://www.s-seriesforum.com/forum/showthread.php?...


"Ran my dyno software – here it goes

4.3 with larger throttle body and headers. Engine is otherwise stock.- results with the following computer compatible Comp Cams hydraulic roller cams:

260AHR – 206,210 at .050 .500”, .500” 112LC
210hp at 4000 321ft/lbs at 2000

266AH – 210,215 at ..050”, .500”, .500” 112LC
219hp at 4000 316ft/lbs at 2000

270AHR – 210,220 at .050”, .500”, .510” 114LC
224hp at 4000 316ft/lbs at 2000

*All combo’s made atleast 300ft/lbs from 2000 – 4500rpm’s
"

Now this was with a TBI system apparently hence "larger throttle body"

quick head flow info:
1995down L35 heads stock 193cfm
1995down L35 heads minor porting 211cfm (at 24” water)


My stock "book power" is
1992-95 4.3L CFI V6 vin W Vortec (early)

165-200hp @ 4400 rpm
235-260tq @ 3600 rpm
With 9.05:1 Compression

If I can get from 260ft-lbs @3600RPM to >_300 ft-lbs by 2000RPM and hold it through ~4500 ( stock shift point) with changing the cam and maybe increasing fuel pressure with an otherwise stock engine I am oK with that. That would basically be the equivilant of me dropping in a stock 350 TBI/harness (which i can get a dime a dozen) and still be able to run the 4l60e with the donor computer, but much less work and time.


Im not trying to run 10's hell im not even trying to run 14's i just want a little more giddyup when someone wants to go light to light, or when im off road more torquey means more fun

This jimmy will be our "toy" for a while until our credit is high enough to get things we need to build a bigger one, but its also gotta be streetable as a daily if one of the other trucks takes a dump. not doing much else to it, just different keys in front, raise the rear and some skinny swamper, inverter and beer cooler inside with a "Decent" sound system.


Back to the post, CPI is supposed to run at 60-66PSI under all conditions? so a higher pressure fuel pump is pretty much out of the question, but what about a higher flowing pump? with the larger cam, id be concerned with it running lean with the stock pump( and im sure its getting weak and whining)



1994 T15 Jimmy 4.3LCPI/4L60E 170K 3.42s (DD)
1988 V20 Suburban W/1995 454TBI(32PSI)/4L80E/NP241 CA truck, 125K G80 14SF/ GM10 4.10's
1995 K1500 ECSB 5.7 TBI/4L60E, 3.73s 269K(wifes)
1996 K3500 ECLB DRW 6.5L TD 3.73's 198K (new project)



 
MuddiGGer25 
Contributor
Posts: 192

Age: 27
Loc: Fargo ND
Reg: 01-25-16
10-29-17 10:09 AM - Post#2712549    
    In response to MuddiGGer25

  • MuddiGGer25 Said:

260AHR – 206,210 at .050 .500”, .500” 112LC
210hp at 4000 321ft/lbs at 2000

266AH – 210,215 at ..050”, .500”, .500” 112LC
219hp at 4000 316ft/lbs at 2000

270AHR – 210,220 at .050”, .500”, .510” 114LC
224hp at 4000 316ft/lbs at 2000





Sooo um i just realized those cams are for TBI engines with no balance shaft so i did some digging quick and came up with these computer controlled options:

262HR-12
Good Torque & Mileage
Part Number: 08-300-8
206,210 at .050 .450”, .480” 112LSA (not worth the effort IMO, too close to stock cpi cam)

262HR-12
Mild Performance, Strong Low to Mid-Range Power
Part Number: 08-302-8
210,220 at .050 .480”, .480” 112LSA

Says "modified computer", more than likely id want this one, or a grind very similar.


266HR-14
Good Mid-Range Power
Part Number: 08-304-8
210,220 at .050 .500”, .510” 115LSA

says with modified computer, intake plenum and runners, higher lift.

I dont think i can run it anyway with stock block due to the .510 lift shown.

276HR-14
High Peformance Street
Part Number: 08-305-8
220,230 at .050 .510”, .510” 114LSA

Definitly not.


290HR-12
Street/Strip Applications
Part Number: 08-306-8
230,244 at .050 .510”, .540” 112LSA

No way in hell lol



Im just confused, i selected chevy small block 262-400 but these cams mention TPI on almost every page but nothing about SFI, CPI, MPFI. and says 305 and 350 except LT1, am i doing something wrong trying to look up the v6 cams, or is it just not a big market?

1994 T15 Jimmy 4.3LCPI/4L60E 170K 3.42s (DD)
1988 V20 Suburban W/1995 454TBI(32PSI)/4L80E/NP241 CA truck, 125K G80 14SF/ GM10 4.10's
1995 K1500 ECSB 5.7 TBI/4L60E, 3.73s 269K(wifes)
1996 K3500 ECLB DRW 6.5L TD 3.73's 198K (new project)



 
MuddiGGer25 
Contributor
Posts: 192

Age: 27
Loc: Fargo ND
Reg: 01-25-16
10-29-17 10:22 AM - Post#2712551    
    In response to MuddiGGer25

nevermind, i just put in "4.3l CPI camshaft balance shaft" in google and i got the right ones now

266HR (Magnum™ Computer Controlled)
Good Low End & Mid-Range • Adjustable Valve Train Required

For '92-'14 GM 4.3L/262 cid 90³ V6 Balance Shaft-Equipped Engines - Works w/ Throttle Body & Sequential Port Injection w/ Aftermarket Chip


Part Number: 56-450-8
210,215 at .050 .500”, .500” 112LSA


I could go that route or maybe for simplicity sake this one:

Magnum Computer Controlled 260AHR; Hydraulic Roller; '92-'14 GM 4.3L w/ Balance Shaft
Part Number: 56-440-8

206,210 at .050 .500”, .500” 112LSA
For '92-'14 GM 4.3L/262 cid 90³ V6 Balance Shaft-Equipped Engines - Works w/ Stock Computer & Fuel Injection • Good Low End Torque & Mileage •



That 2nd one is the same grind as the first one in the list from the dyno simulation above, but for balance shaft 4.3's, so i would hope to see close #'s real world.


FWIW i work across the street from a performance shop that has a dyno, might have to drag the jimmy over there one day and get a benchmark before i do any work to it.


1994 T15 Jimmy 4.3LCPI/4L60E 170K 3.42s (DD)
1988 V20 Suburban W/1995 454TBI(32PSI)/4L80E/NP241 CA truck, 125K G80 14SF/ GM10 4.10's
1995 K1500 ECSB 5.7 TBI/4L60E, 3.73s 269K(wifes)
1996 K3500 ECLB DRW 6.5L TD 3.73's 198K (new project)



 
gchemist 
Senior Chevytalk Moderator
Posts: 24323
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
10-29-17 10:37 AM - Post#2712553    
    In response to MuddiGGer25

If you put it in, next time I'm in Watertown SD, I may drive up for a visit.

'95 Jimmy SLT (Bought @131,814)
'83 Silverardo XST - ZZ4 powered
'96 GMC Jimmy LS Ret. @236651 miles


 
MuddiGGer25 
Contributor
Posts: 192

Age: 27
Loc: Fargo ND
Reg: 01-25-16
10-29-17 10:49 AM - Post#2712555    
    In response to gchemist

  • gchemist Said:
If you put it in, next time I'm in Watertown SD, I may drive up for a visit.



We actually have moved to fargo, nd so not far from there at all now

I will definitly be putting in "a" cam just have to figure out which one, i keep seeing contradicting stories on whether or not i can go with .500 lift or only .480 without machining due to some valve guide issue or something. i thought that was just the 96+ not the 92-95 ones. idk, ill figure it out. probably drag one of my coworkers thats been to college and post grad for this kinda stuff over on a weekend and put it in once ive made a decision, then i can go back to working on the 454 cam decision

actually just noticed your thing says austin tx, we are gonna be down in St.Joseph for Rednecks with paychecks this spring break ( dont know your opinion on such things) but maybe could meet if your around the area?

1994 T15 Jimmy 4.3LCPI/4L60E 170K 3.42s (DD)
1988 V20 Suburban W/1995 454TBI(32PSI)/4L80E/NP241 CA truck, 125K G80 14SF/ GM10 4.10's
1995 K1500 ECSB 5.7 TBI/4L60E, 3.73s 269K(wifes)
1996 K3500 ECLB DRW 6.5L TD 3.73's 198K (new project)



Edited by MuddiGGer25 on 10-29-17 10:53 AM. Reason for edit: No reason given.

 
gchemist 
Senior Chevytalk Moderator
Posts: 24323
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
10-29-17 11:01 AM - Post#2712558    
    In response to MuddiGGer25

Read this on CPI: http://www.chevythunder.com/gm_cpi_and_cspi_19922 0...

Sure, I'll give ya a ride in the '95 Jimmy. Or even better BADBOW. I should be here most of Spring Break week. Bring your rebel flag!!

Attachment: badbow.jpg (165.92 KB) 25 View(s)


BADBOW


'95 Jimmy SLT (Bought @131,814)
'83 Silverardo XST - ZZ4 powered
'96 GMC Jimmy LS Ret. @236651 miles


Edited by gchemist on 10-29-17 11:03 AM. Reason for edit: No reason given.

 
MuddiGGer25 
Contributor
Posts: 192

Age: 27
Loc: Fargo ND
Reg: 01-25-16
10-29-17 03:23 PM - Post#2712588    
    In response to gchemist

im reading it now, I think RWP spring break is Mar 15-18 this coming year lol. just trying to figure out what we will be bringing besides the jimmy.

you got a picture of your fullsize one?

1994 T15 Jimmy 4.3LCPI/4L60E 170K 3.42s (DD)
1988 V20 Suburban W/1995 454TBI(32PSI)/4L80E/NP241 CA truck, 125K G80 14SF/ GM10 4.10's
1995 K1500 ECSB 5.7 TBI/4L60E, 3.73s 269K(wifes)
1996 K3500 ECLB DRW 6.5L TD 3.73's 198K (new project)



 
gchemist 
Senior Chevytalk Moderator
Posts: 24323
gchemist
Loc: Austin, TX 78748
Reg: 05-09-00
10-30-17 05:15 AM - Post#2712669    
    In response to MuddiGGer25

I don't have a full size Jimmy. I would like one though. If I ever came across a 4x2 Blazer or Jimmy, I would jump on it. Plans would be drop in a 5.3 or 6.0 LS motor and OD trans. I will probably have to travel the back half of that week.

'95 Jimmy SLT (Bought @131,814)
'83 Silverardo XST - ZZ4 powered
'96 GMC Jimmy LS Ret. @236651 miles


 
MuddiGGer25 
Contributor
Posts: 192

Age: 27
Loc: Fargo ND
Reg: 01-25-16
10-30-17 10:06 AM - Post#2712703    
    In response to gchemist

Nice lol, i want to do a SAS on my s15 jimmy but dont have the equipment or knowledge yet to do it. so for now just enhancing whats there and saving and learning.

we will most likely end up there wed the 14th so we can get camp setup and relax at first. we will be towing our jimmy so if i do break something i can just winch it on and go home lol

1994 T15 Jimmy 4.3LCPI/4L60E 170K 3.42s (DD)
1988 V20 Suburban W/1995 454TBI(32PSI)/4L80E/NP241 CA truck, 125K G80 14SF/ GM10 4.10's
1995 K1500 ECSB 5.7 TBI/4L60E, 3.73s 269K(wifes)
1996 K3500 ECLB DRW 6.5L TD 3.73's 198K (new project)



 
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