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Engine SwapEverything about swapping an engine into your Third Gen.....be it V6, V8, LTX/LSX, crate engine, etc. Pictures, questions, answers, and work logs.
Thought I'd post my results on swapping the LB9 305TPI (1991) T5 with a 383 Stroker with FIRSTŪ TPI intake T56. Please feel free to ask questions in the comments. Hopefully that will help others interested in this kind of swap.
I posted some T/HP numbers at the end. This is not for argument or debate or bragging. It is just for comparison and to give an idea of what can be accomplished (give & take). There are many other set-up possible which would probably yield better numbers. That's not the point here. However, feel free to add comments on how it can be improved as long as it's TPI, not LSX nor carbureted and street friendly.
Engine is a 2018, 383 stroker GM crate SP383 Deluxe (GM part #19355672 assembled in Mexico):
Bore x Stroke (in.): 4.000 x 3.800
Block (P/N 88962513): Cast-iron with 4-bolt main caps
OE 105amp alternator, power steering pump, water pump, underdrive pulleys, no AC & no smog pump.
OE radiator
180° F. Thermostat
OE dual electric fan, both ECM controlled
Cooling set up functions really good in my northern summer season (extreme max 95°F, might be an issue if racing or very hot weather like TX, AZ, FL, etc...)
Car weights 3525lbs full gas tank. With me in it 3700lbs. On Toyo TQ drag radial 275/45R16 (15psi), at track, 3.89 Motive rear gear. Moser 9in, Eaton Detroit Truetrac, I get @ 65Deg.F 50% Humidity 101 Baro (321' elevation):
Thought I'd post my results on swapping the LB9 305TPI (1991) 5MT to a 383 Stroker with FIRSTŪ intake 6MT. Please feel free to ask questions in the comments. Hopefully that will serve others interested in this kind of swap.
Engine is a 383 stroker GM crate SP383 Deluxe (GM part #19355672):
Bore x Stroke (in.): 4.000 x 3.800
Block (P/N 88962513): Cast-iron with 4-bolt main caps
Cylinder Heads (P/N 19300955): Fast Burn aluminum;
62-cc chambers
Valve Size (in.): 2.000 intake / 1.550 exhaust
Compression Ratio: 9.6:1
Rocker Arms (P/N 19210724): Aluminum roller style
Rocker Arm Ratio: 1.5:1
Recommended Fuel: Premium pump
Ignition Timing: 32° total at 4000 rpm
Maximum Recommended rpm: 6000
Balanced: External
Induction system:
FIRSTŪ Intake 835cfm
Bosch III Injector 32lbs/hr (they reach max of 80% duty at WOT)
ECM7730 with Moats emulator, S_AUJP v6.0, custom tune (by me!)
Adjustable fuel pressure regulator, set at 43.5lbs (with vacuum disconnected)
Walbro 255lph fuel pump
OEM hard fuel lines
Pump gas 91 octane with Boostane = 98 octane
Custom 4in cold air intake with zero restriction up to 6000 rpm
AFR at WOT is 12.6-13.0 depending on temperature
Ignition:
OE style HEI with remote coil
30* maximum SA at WOT (no significant difference on dyno between 32* and 28*)
Maximum SA reached at 3200RPM
No knock control
Exhaust:
Hedman headers #68470, shorty 3in collector, 1 5/8 primary (flanged modified to fit Vortec heads)
Custom Y-Pipe 2.5in dual to single 3in with high flow cat
Custom 3in single with Hooker exhaust dual pipes
Accessories:
LB9 OE brackets
OE 100amp alternator, power steering pump, water pump, no AC, no smog pump.
OE radiator (function really good in my northern summer season, might be an issue if racing or very hot weather)
OE dual electric fan, both ECM controlled
EVAP system still in place
PCV system still in place with oil catch can
Car weights 3525lbs full gas tank. With me in it 3700lbs. On Nitto 555R drag radial, on the street, T56, 3.89 rear gear, I get:
60' 1.652
330' 5.196
1/8 8.135
MPH 84
1000' 10.636
1/4 12.708
Trap Speed 108
0-60mph 4.5
Oh yeah!! Problem being: you get used to it and you want more lol. I was discussing pros and cons of Nitrous Oxide System with the performance shop. With the hypereutectic pistons, I'm worried I'll melt the engine or definitely shorten its life. Also, part of the drive train has its limits too.
Nice build! I'm working on a similar project and I'm looking to purchase some shorty headers. What kind of modifications had to be done on your header flanges to work on your Vortec heads?
What kind of modifications had to be done on your header flanges to work on your Vortec heads?
I reused the 1 5/8" primary shorty hedman headers #68470 that had been installed by the PO on the old LB9. One would think why the heck would you do that? Here are the reasons:
1) They fit perfectly with no clearance issue on my set-up
2) Zero cost at the time
3) Nothing available that would fit my single exhaust set-up for OEM M5 bellhousing and transmission crossmember/torque arm set-up
4) Optimal headers (1 3/4" primary for Vortec heads port) would have required expensive modifications to hydraulic clutch, bellhousing, crossmember/torque arm set-up and exhaust system.
I know they are not optimal for power. I get robbed some HP for sure. In my case it was irrelevant. For someone else it could be a big issue.
I decided to match the gasket to the headers and not the exhaust port. It seals perfectly using the Mr. Gasket copper #7150MRG. The picture shows the mismatch with bolt holes. That's the part that had to be modified on the gasket and headers flange. Using a carbide bit, the holes had to be elongated precisely so the gasket and flange would match. I used the gasket as a template so the exhaust ports would be "centered aligned". As you can see on the picture, the gasket is not optimal for the exhaust port shape. The installation was done with engine on stand so I could match everything correctly. Trying to do this with the engine in the engine bay is probably impossible.
IMO the best option is full on custom headers. That requires expertise and $$$$. If I ever find that kind of expertise around my neck of the woods, I will consider it. I don't know how much HP at the wheel it represents though.
I really like your Thread so far, and I like your Engine Swap Project.
Now that most people are swapping to the Gen-III/ Gen-IV SBC Engine instead of the Gen-I SBC Engine...
I really like to see these Swaps!
I am in now way shape or form trying to diminish what you have done.
However I would like people to know that they can do a Swap like yours, for roughly the same budget...
And optimize the Build with a little research into Valve Events and Engine Performance...
And walk away with Power in the range of what you are making, up to another 100ish Horse-Power and 40 to 50 Ft/ Lbs of Torque.
People do not need to swap to a Gen-III/ Gen-IV SBC Engine, to have a 500 to 550 HP Engine that is very streetable.
Congrats on your Swap!
And again, it's great to see a Gen-I SBC Build!!!
I really like your Thread so far, and I like your Engine Swap Project.
Thanks for all the kind words.
Originally Posted by vorteciroc
I am in now way shape or form trying to diminish what you have done.
However I would like people to know that they can do a Swap like yours, for roughly the same budget...
And optimize the Build with a little research into Valve Events and Engine Performance...
And walk away with Power in the range of what you are making, up to another 100ish Horse-Power and 40 to 50 Ft/ Lbs of Torque.
Absolutely! They're are other combinations that would produce more HP with a 383 without being too loopy. The crate engine was a compromise, again not having access to local expertise made me go for the GM crate. However with a TPI intake, 500-550 peak HP could be difficult. For me, the TPI set-up was a must as I wanted to retain OE look. These guys did a great job on this one at 460HP:
And Yes, you are correct, as the Intake-Manifold is a BIG restriction.
The TPI Configuration would have to go...
You are not going to see those High Power Numbers at Atmospheric Pressure.
And Yes, you are correct, as the Intake-Manifold is a BIG restriction.
The TPI Configuration would have to go...
Absolutely, the TPI was not designed for high rpm peak HP.
Here's an interesting chart comparing the SP383 Deluxe with the FIRSTŪ TPI Intake vs. GM Eliminator Vortec Intake Manifold with Holley 770cfm carburetor (what GM tested it with). For my needs, on the street, I find the TPI gives me more usable HP, specially in town when I want to keep the rev down. I never drag race and rarely do standing start accelerations. I like quick low rpm rolling accelerations. It keeps the law enforcement at bay. Getting to a stunting charge 0.1 or 0.2 sec faster is irrelevant lol. Just food for thought. It all depends on the application and what one wants. Also, what kind of HP/TQ the drive train and chassis are able to take.
Are you referring to an Intake Manifold... or an Air Induction System?
I should have written "FIRSTŪ TPI Intake"
I corrected some of the thread but can't correct the title.
I see someone gave you the link https://firstfuelinjection.com/
Cheers
Your Cylinder Heads have raised Exhaust-Ports...
There should be a Gasket Set that is intended to fit.
Raised Intake or Exhaust Ports are much more common in Higher Performance Heads.
Yes! Raised port 0.200". Gasket Fel-Pro #1470. Problem with my set-up is the vortec gasket would not seal my headers. And "bolt-on" headers that would fit my set-up are not available. For this swap, if one wants to maximize the exhaust, one needs long tube headers with custom exhaust which most likely requires to do away with OE hydraulic clutch/fork and a need for custom transmission crossmember to accept long tube headers.
Here's what GM Performance recommends: "The SP383 High Performance engine should be installed with a pair of high performance headers for maximum performance. The headers used during development of the SP383 had 1.75" diameter primary tubes. Primary tubes were approximately 32.00" in length and had 3.00" diameter collectors. Using a similar combination in your application, along with a performance exhaust system with a balance tube (“H” pipe) and low restriction mufflers, will provide you with optimum performance from your SP383 High Performance engine."
Which (Brand/ Model/ Part Number) "Vortec" exhaust gaskets did you try?
If the dimensions of the Gasket were correct or even close...
And they did not seal well...
Some of these Gaskets (depending on what material they are made of) can be doubled-up to seal better.
Which (Brand/ Model/ Part Number) "Vortec" exhaust gaskets did you try?
If the dimensions of the Gasket were correct or even close...
And they did not seal well...
Some of these Gaskets (depending on what material they are made of) can be doubled-up to seal better.
The Fel-Pro 1470. But I have to explain better lol. I was worried, the gasket (#1470) would not seal properly by looking at the mock-up. Those headers were not made to fit the Fast burn heads. The headers flange has a round matting surface were the round copper gasket fits nicely. Since the headers flange was already interfering with the port exhaust anyway, I decided to play safe and go with the round copper gasket. Would the #1470 gasket had sealed? Maybe. Would I had taken a chance? No. Doubling-up could have created a bolt length problem and also clearance issue. Let's say, I went with the easy and safe route the day I had to make the decision... among many many other decisions.
Unless your Header Flanges are perfectly straight (which most of the time they are not) the Copper Gaskets will not seal well.
"Dead-Soft" Aluminum Gaskets are amazing...
Otherwise I would definitely try a different Material than Copper (no plain Paper either; they blow-out very easily).
Unless your Header Flanges are perfectly straight (which most of the time they are not) the Copper Gaskets will not seal well.
I've heard that argument many times. Even have a local guy who had that problem when he was flooring it. He could hear the exhaust whistling. I guess I'm lucky on this one. Every time I inspect, there is no evidence on any leaks. And I do inspect on regular basis top to bottom using my hoist.
Thought I'd post my results on swapping the LB9 305TPI (1991) T5 with a 383 Stroker with FIRSTŪ TPI intake T56. Please feel free to ask questions in the comments. Hopefully that will help others interested in this kind of swap.
I posted some T/HP numbers at the end. This is not for argument or debate or bragging. It is just for comparison and to give an idea of what can be accomplished (give & take). There are many other set-up possible which would probably yield better numbers. That's not the point here. However, feel free to add comments on how it can be improved as long as it's TPI, not LSX nor carbureted and street friendly.
Engine is a 2018, 383 stroker GM crate SP383 Deluxe (GM part #19355672 assembled in Mexico):
Bore x Stroke (in.): 4.000 x 3.800
Block (P/N 88962513): Cast-iron with 4-bolt main caps
OE 105amp alternator, power steering pump, water pump, underdrive pulleys, no AC & no smog pump.
OE radiator
180° F. Thermostat
OE dual electric fan, both ECM controlled
Colling set up functions really good in my northern summer season (extreme max 95°F, might be an issue if racing or very hot weather like TX, AZ, FL, etc...)
Car weights 3525lbs full gas tank. With me in it 3700lbs. On Toyo TQ drag radial 275/45R16, on the street, 3.89 Motive rear gear. Moser 9in, Eaton Detroit Truetrac, I get @ 77Deg.F 40% Humidity 103 Baro (sea level):
What do you shift at.. we found ours is only shifting at 5000 rpms leaving a little on the table she managed a best of 12.2 at 110 I want her to shift at 5500 rpms I think she'll pick up a .1 or .2 we'll be going out in a few months hopefully...
What do you shift at.. we found ours is only shifting at 5000 rpms leaving a little on the table she managed a best of 12.2 at 110 I want her to shift at 5500 rpms I think she'll pick up a .1 or .2 we'll be going out in a few months hopefully...
I believe, the theory is to maximize average HP on each gear (the area under the curve). So your shift points should be based on your engine HP curve, but also transmission gear ratios. I have a T56, you have an AT. So it might be hard to compare. On my 1st to 2nd to 3rd to 4th gear, it drops just over 1800RPM each time. So I did the math and I have to shift at 6000RPM (engine max RPM) on 1st-2nd and 3rd. From 4th to 5th it drops 1100RPM and from 5th to 6th it drops 1200RPM. So on the 4th and 5th there is no need to rev pass 5500RPM.
Even if HP starts decreasing pass 5000RPM, there is less HP loss from 5000 to 6000RPM compare to the HP loss of shifting lower than 6000RPM. It's simple math. Plus I get the benefit of lower gear.
Example (all things being equal): if I was to shift at 5000RPM on 3rd gear, it would drop to 3500RPM instead of 4200RPM on 4th gear. I would lose ave HP from 5000 to 6000RPM on 3rd gear (404 to 383HP) and gain ave HP from 3500 to 4200RPM on 4th gear (330 to 386HP). Simplified way of calculating the delta is using area of right triangle + area of rectangle. Let's say 25HP = 25 units and 50RPM = 50 units, basically 1 for 1.
Loss of HP on 3rd gear
Right triangle [((404-383)/25) * ((6000-5000)/50)]/2 = 8.4
Rectangle [(383/25) * ((6000-5000)/50)] = 306.4
Total loss 314.8 units
Gain of HP on 4th gear
Right triangle [((386-350)/25) * ((4200-3500)/50)]/2 = 10.1
Square [(350/25) * ((4200-3500)/50)] = 196.0
Total gain 206.1 units
Delta = minus 108.7 units
So I would rather push on the 3rd gear up to 6000RPM and gain 108.7 units of power combine with lower gear.
For your AT, you'd have to see what can be done. Have no clue of your gear ratios and how AT can be adjusted. Not my cup of tea. I would say if it shifts at 5000RPM, it appears low, but it all depends where it lands. If you take my HP curve for instance. If it shifts at 5000RPM and lands around 4200RPM, there would be no gain, at first glance, in having it shift at 5500RPM and land at 4600RPM (the drop is accentuated the higher the rpm is). Maybe a gain in working longer on a lower gear though.
If you compare your 1/4 mile to mine, you have faster ET because mine is almost a rolling start, but I get faster trap speed. So I would say, you are leaving HP on the table.
Check this calculator online. It's a different explanation but the same principles. It uses torque numbers with gear ratios. It pretty much confirmed my own calculations.
We have a 3.54 gear ratio the car imo i think will benefit from a higher shift point from 2nd to 3rd car imo still has more on top then 5000 rpms.. lol only true way to find out will be trial and error on the strip..
We have a 3.54 gear ratio the car imo i think will benefit from a higher shift point from 2nd to 3rd car imo still has more on top then 5000 rpms.. lol only true way to find out will be trial and error on the strip..
Sure! Nothing like real world testing.
Remember, the rear gear ratio does not affect the drop in RPM between transmission gear (shift).
Problem is the 700r4 has such a low 1st gear then it drops alot to second then 3rd..the transmission is setup uses a governor to make it shift at max rpm unfortunately it's set to a stock 305 or 350 tpi which we all now doesn't make much power past 4500 rpm so with the Change in the motor now with the bigger cu inch.. cam etc the stock shift points dont cut it imo..so for it to run as decent as it is only tells me it definitely has more in it..just sucks it can't be adjusted like modern day car thru the computer the 700r4 uses a TV cable and that governor only way it to manually shift it which is our next time out.
What intake gasket are you using with your First TPI and the fastburn heads? i see you are using the traditional 6 per side bolt pattern vs the vortec... i am doing a similar build and wondering on the intake gasket
What intake gasket are you using with your First TPI and the fastburn heads? i see you are using the traditional 6 per side bolt pattern vs the vortec... i am doing a similar build and wondering on the intake gasket
thanks and great looking build
Thank you!
I used the FIRST TPI intake gasket. I believe it's a 1204 style but made to fit traditional or Vortec. Check with Ken at https://firstfuelinjection.com/
As you can see, I don't drive it much. Around 800 miles per summer. It took a while to fix a drivetrain vibration, so the car sat more than it should have been. Vibration is finally fixed (https://www.thirdgen.org/forums/tran...s-another.html).
This summer I was finally able to take it to an official dragstrip. It performed as expected with a 3700lbs, 400HP street car.
All in all, I am very satisfied with the set-up. It does what it was intended to do. It performs really well on the street but lacks traction and top end at the dragstrip. Nothing surprising as the engine is rated at 6000rpm max and the TPI is restrictive. If you want it to perform at the dragstrip, you need a carburetor and more traction. The main thing is the whole set-up stays true to the "Formula" concept and TPI era. If not, well, I would have gone LS for sure.
The engine is low maintenance. The spark plugs look good (inspected every spring) and compression is equal on all 8 at around 185psi. Spark plugs get a bit orange with the use of boostane. Easy to clean though. Oil pressure is always normal using Royal Purple 10W30. It gets a bit low at 850rpm warm idle, around 10 psi. I'm not worried. No leaks, no over heating, no weird noises. The valvetrain is a bit chatty, but it was like this from factory. Nothing over the top. No exhaust leaks despite the "funky" headers/vortec head fitment. I am a bit surprise with that. Fingers crossed! Engine warms up quickly on start-ups, way quicker than OEM. I like that.
Engine, with this set-up, does not like the 1800-1900 rpm range. It feels like it's misfiring. Barely perceptible. I tried playing with the tune but nothing really works. Solution is to run the engine at lower RPM when cruising at mid speed. It actually increases fuel economy and quiets the loud exhaust. 50mp/h at 1600rpm yields 24mpg!!!!!!!!!! If you rev over 2000 rpm, mpg goes to sh** but the engine loves it. On the highway at 60-75 mph, it's perfect, the engine revs in the 2000-2300rpm. Average fuel economy, the way I drive, is 15mpg. If you baby it on highway, you can get 19mpg.
One thing though. Oil consumption seems a bit much. I can't pin point what causes it. It's not leaking, the plugs are not fouled, it's not smoking or smelling. The blow by don't seem excessive. Compression is good, but did not do leak down test yet. The catch can yields less than 1 oz per 625 miles. I calculated the "burn" rate at 0.8 quarts per 700miles. I am not too worried about it for now. Engine break in was done according to GM's specs. However, I did not use engine break in oil, just conventional 10W30 then switched to synthetic after break-in period. I'll figure it out one day I guess. I have to take it on the highway for a day at steady cruise for a long run and see how it does for oil consumption (measure before and after). Nothing to worry in my case, but something to keep an eye on.
The low-mid range rpm torque combined with the throttle quick response is phenomenal. I don't feel it as much because I'm used to it now. Still makes me laugh every time. If I take a passenger on, it instantly brings a smile to their face. Car feels fast and intimidating.
Here's a statement from a 480 HP EV owner who rode shotgun with me: "you can get that much fun with an EV"... as he was grinning from ear to ear. The guy is a race car driver!!!!
In the end, it's not all about numbers... and we are way too hard on ourselves when it comes down to evaluating our build.
Great update... sounds like you are quite happy and having great fun with your set-up... I am just finishing a FIRST install and looking forward to it based on your reports!
@alan91z28 , have you finished your FIRST install?
yes i have and i just over the last couple weeks have gotten it fired up and about 200 miles on it... have it tuned in pretty reasonable and i am lovin' it!
09-17-2021, 01:17 PM
