Tuning a 93 3.4 Firebird

[tkoforpresident]

The heads are heavily modified, and the 109 LSA is the same as the stock 3.4 iron head cam, I just added a bit more duration and changed the intake center line. Those lift numbers are at 1.5 rockers and Comp recommends to leave .060" clearance for the springs and we are right below that actually - I warned Max this was going to be a tough one to pull off with the stock tune, yet he said go for it lol.

Got Lope?

And i stand by that decision.

This is why we are tuning.....

[IsaacHayes]

Do you have the OBD1 swap in yet?

[tkoforpresident]

Do you have the OBD1 swap in yet?

errr no, i'm still waiting for John to send it to me in the mail

but once i do receive it, I'll read the .bin that is sent along with it and do some modifying, maybe even before i data log for the first time.

Then i'll get some data logs in and post them up and see where to go from there.

[60dgrzbelow0]

The heads are heavily modified, and the 109 LSA is the same as the stock 3.4 iron head cam, I just added a bit more duration and changed the intake center line. Those lift numbers are at 1.5 rockers and Comp recommends to leave .060" clearance for the springs and we are right below that actually - I warned Max this was going to be a tough one to pull off with the stock tune, yet he said go for it lol.

Got Lope?

I understand now, John... Thanks. That .060" clearance you allowed for...is it at the top because the rocker arms can bang into the top of the springs... or the bottom because the cup/slot runs out of space when tilted at such an extreme angle to make the 1.6 to 1 lift ratio?

[60dgrzbelow0]

swap to OBDI & go with a 3500-youll be MUCH happier & itll be much cheaper, plus way more power potential & way better mpg.

with OBDI you can get a PROM programmer for 120 for everything & tune it-with OBDII you need a HPtuner tuner (500-600 bucks) & credits ($50-$200).

Here is your answer...

"Not everyone has the time or resources to drop in a 3500 or make a hybrid. A lot of people just want their car back on the road or to get it back to the condition it was in before a cylinder head cracked, cam went flat or a valve burnt out..."

[tkoforpresident]

Amen Bob!!

[60dgrzbelow0]

Amen Bob!!

And ... "Amen... Betterthanyou..."

[ForcedFirebird]

Actually Max, you should be fine on the retainer to stem seal clearance, it's the springs that will stack first. Comp recommends .060" clearance from max lift to spring stack on the 980's, you have .059" on the ehaust side

As far as the 3500 top end swap debate, it's simply not for everyone. The biggest deal in the 93-95 f-bodies is the fact that the ECM has to be swapped to either OBDI or II, and not a lot of people are willing to deal with that, the accy bracket modifications, EGR location, throttle cable, or dealing with a high compression (or changing pistons). A nicely ported top end with a hot cam designed around the lift and flow limitations can make a decent combo and can be installed by the less-than to average garage mechanic.

[60dgrzbelow0]

The heads are heavily modified, and the 109 LSA is the same as the stock 3.4 iron head cam, I just added a bit more duration and changed the intake center line. Those lift numbers are at 1.5 rockers and Comp recommends to leave .060" clearance for the springs and we are right below that actually - I warned Max this was going to be a tough one to pull off with the stock tune, yet he said go for it lol.

Got Lope?

John...when you get "Half-A-Tick"... If you are still working on Iron Heads anymore, would you please email me via ( at60dgrzbelow0@yahoo.com) with your price plus S&H (either with the re-conned heads I've already had done...or adjusted for your available "Irons" that are local in South Florida.)

Since everything I've done to date is fairly mild on this motor and not nearly as "edgy" as what Max is attempting... I'd like to know your opinion as to whether porting and polishing these 'locomotive rails' would make enough of a difference to mess with, what with it being so close to the final stages of the build. The current work and mods include the following:

1995 Firebird L-32 3.4L 207 C.I.D. Engine Block
(Prep and Machine Work done by Godwin-Singer, St. Petersburg, Florida)

Bored 0.75 MM
New SpeedPro OS Pistons/Rings
Polished Journals on Stock Cast Iron DIS Crankshaft
CompCam 260H Cam Shaft
Crane Hydraulic Lifters
Melling Push Rods
Reconditioned Stock Iron Heads with standard, stock EFI sized Valve Work
ComCam Roller Tipped Rockers @ 1.52-1
CompCam Heavy Duty Valve Springs/Keepers, etc.
Pacesetter Ceramic Coated Headers into welded CAT (Courtesy Driver_10)
Stock ECM/PCM and all new sensors for crankshaft and camshaft needs.
Modified Throttle body (upped from 52MM to 55MM)
Modified UIM (Ported and matched to TB @ 55MM)
FelPro Gasket Sets throughout
REMFLEX Graphite Header Gaskets (via Honda Civic ARP Pressure Plate Bolts)
Stage 3 Intake
CAT-Back Dual Exhaust

That's all...so far.

As far as the 3500 top end swap debate, it's simply not for everyone. The biggest deal in the 93-95 f-bodies is the fact that the ECM has to be swapped to either OBDI or II, and not a lot of people are willing to deal with that, the accy bracket modifications, EGR location, throttle cable, or dealing with a high compression (or changing pistons). A nicely ported top end with a hot cam designed around the lift and flow limitations can make a decent combo and can be installed by the less-than to average garage mechanic.

That would be...me!

[tkoforpresident]

too bad i can't get some flow #'s on those heads you did for me John, now that you have the flow bench up and running....

I'd be curious to see what kind of improvement they made over stock

[60dgrzbelow0]

Teek... You COULD loan them to me... Then I could give you an empirical opinion of their performance... with no need for the Flow Bench Tests

[60dgrzbelow0]

What 19 Lbers did you choose... the Accels?

[tkoforpresident]

What 19 Lbers did you choose... the Accels?

stock 3.8 Firebird/Camaro injectors.

[IsaacHayes]

Wow, 3.8 had only 19lb/hr injectors??????? That doesn't make sense... Those are 200hp rated motor, my motor is rated 160hp and I'm hitting 92% duty cycle in the upper RPMs with my mods... Did the 3.8 run higher than 43.5psi fuel pressure?

[60dgrzbelow0]

stock 3.8 Firebird/Camaro injectors.

Max...if they are the Rochester Multech II variety...you didn't happen to make a note of their number...did you? ...Its either embossed in white or etched into the edge of the black plastic coil housing. When I pull the old 3.4L Engine from the Black Camaro... I'll yank the Accel 19 Lbrs (High Impedance) off the Fuel Rail, then I'll run them through "The FrankInjector" Cleaning Machine a few times and after tidying them up until they are nice and clean, I'll send them to you to D*ck around with if you like... No Charge...