300 HP Bolt-on L03 TBI
08-13-2007, 08:01 PM
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Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
300 HP Bolt-on L03 TBI
Thats right, if you consider a pair of heads a bolt-on, which I do.
Stock #155 Peanut roller camshaft(4* Retard & 1.6:1 full roller rockers)
Stock port 059 Vortecs from a 2002 Express Van (back-cut valves), milled .025" (9.75:1 compression using 3.8" bore, 0.016" rubber embossed steel shim head gasket)
Edelbrock Performer Carb intake (milled to mate with milled heads)
2.00" 454 TBI unit w/ 80# injectors @ 12 psi
GM 454 TBI-Q-Jet manifold adapter
Hooker headers into single 3" exhaust
Custom Prom tuning
255 RWHP @ 4,900
310 RWTQ @ 3,200
The torque curve starts with nearly 285 RWTQ at just 2,000 rpm, obtains 300 ft/lbs @ 2,400 and doesn't fall below 285 ft/lbs to 4,600 rpm. That is about as flat as it gets. In normal driving it grunts hard from just off-idle all the way to 5,000 rpm. When the transmission shifts at 5,000 rpm the engine is still pulling and pulls hard immediately after the upshift.
BTW, this is the same engine that I already had in my 1991 G20 Van, save for the Peanut roller camshaft. I pulled the Crane 266H10 out of it as it was not the torquiest cam.
[IMG]
[/IMG]
(shown with cast-iron exhaust manifolds and a Holley Projection TBI adapter
Stock #155 Peanut roller camshaft(4* Retard & 1.6:1 full roller rockers)
Stock port 059 Vortecs from a 2002 Express Van (back-cut valves), milled .025" (9.75:1 compression using 3.8" bore, 0.016" rubber embossed steel shim head gasket)
Edelbrock Performer Carb intake (milled to mate with milled heads)
2.00" 454 TBI unit w/ 80# injectors @ 12 psi
GM 454 TBI-Q-Jet manifold adapter
Hooker headers into single 3" exhaust
Custom Prom tuning
255 RWHP @ 4,900
310 RWTQ @ 3,200
The torque curve starts with nearly 285 RWTQ at just 2,000 rpm, obtains 300 ft/lbs @ 2,400 and doesn't fall below 285 ft/lbs to 4,600 rpm. That is about as flat as it gets. In normal driving it grunts hard from just off-idle all the way to 5,000 rpm. When the transmission shifts at 5,000 rpm the engine is still pulling and pulls hard immediately after the upshift.
BTW, this is the same engine that I already had in my 1991 G20 Van, save for the Peanut roller camshaft. I pulled the Crane 266H10 out of it as it was not the torquiest cam.
[IMG]
[/IMG](shown with cast-iron exhaust manifolds and a Holley Projection TBI adapter
Last edited by Fast355; 08-13-2007 at 08:14 PM.
08-14-2007, 01:58 AM
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Car: 83 POS monte carlo 2015 chevy P/U
Engine: 92 5.7 tpi 5.3
Transmission: 700r4 6L60E
Axle/Gears: 2.42 too high
Re: 300 HP Bolt-on L03 TBI
Fast355, you just keep coming up with aces. nice numbers 
i picked up a 87 SS last week with no motor or trans, so im going to be doing the TBI/350 Vortec/ 4L60E/ 427 budget build pretty soon, just waiting to get the title before i start in on it. i'll probably be having some questions for you as i build it.
i think im going to use a cam similar to the LT4 but with a little more lift, i want to keep a nice smooth idle.
i picked up a 87 SS last week with no motor or trans, so im going to be doing the TBI/350 Vortec/ 4L60E/ 427 budget build pretty soon, just waiting to get the title before i start in on it. i'll probably be having some questions for you as i build it.
i think im going to use a cam similar to the LT4 but with a little more lift, i want to keep a nice smooth idle.
08-16-2007, 12:53 AM
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Car: '92 Toyota Pickup
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Re: 300 HP Bolt-on L03 TBI
Considering the amount of gain that rests on the tuning of the ecu There is much that has not been revealed/proven in relation to the LO3.
08-19-2007, 02:29 PM
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Re: 300 HP Bolt-on L03 TBI
Fast, how does it sound? Does it still sound "tinny" with the stock cam? That was my biggest complaint when I had nearly every bolt on still running the stock cam.
08-21-2007, 05:03 PM
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Car: 1993 Caprice LTZ
Engine: 350 TBI
Transmission: 4L60 (700R4)
Re: 300 HP Bolt-on L03 TBI
Fast...I don't know how you do it...but I wish I did!!! I personally think you can make an engine that fits any car...truck...or van!!!!
I have that same cam in my Caprice...obviously I hate it...with stock 193's...its such a dog when compared to other 350 cam's....I did as many bolt on's as I could and that was just barely enough to wake it up...
I have that same cam in my Caprice...obviously I hate it...with stock 193's...its such a dog when compared to other 350 cam's....I did as many bolt on's as I could and that was just barely enough to wake it up...
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08-22-2007, 06:33 AM
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Re: 300 HP Bolt-on L03 TBI
I swear you build an engine every other week just because you can, not because you need it. Those are pretty good numbers for a 305. Was a can of paint not in the budget or do you just like rusty thermostat housings?
02-14-2008, 05:18 AM
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Car: 91 Trans am
Engine: built 360 TBI
Transmission: built 700r4
Axle/Gears: 10bolt/3.23
Re: 300 HP Bolt-on L03 TBI
Would this set up make the same power with lt1 cam, gmpp vortec intake gm#12496821 (would it even fit) and stock tb with higher fuel pressure?
02-14-2008, 10:53 AM
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Car: 88 V6 'bird/89TBI bird/85 T/A
Engine: 2.8/TBI/TPI
Transmission: V8 T-5/700R4 x2
Axle/Gears: 3.42 open/2.73 open/ 3.27 9 bolt
Re: 300 HP Bolt-on L03 TBI
I'd like to see that exact same engine with a 5.7 TPI cam, and then a stock LT1 cam. Got that in your future?
Inquiring minds want to know!
Inquiring minds want to know!
02-14-2008, 12:55 PM
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Car: 90 Firebird Formula
Engine: LO3
Transmission: T5
Axle/Gears: 3.08 one wheel peel
Re: 300 HP Bolt-on L03 TBI
Yeah, i'm surprised you went back to a factory cam. The peanut cam you talk about, is the stock roller LO3 cam, right?
Does using that cam make it easier to tune, even with the other mods?
Does using that cam make it easier to tune, even with the other mods?
02-15-2008, 07:36 PM
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Car: 89 iroc-z
Engine: 305tpi
Transmission: wc-t5
Axle/Gears: 10 bolt 3.08 posi (4 now)
Re: 300 HP Bolt-on L03 TBI
thats amazing that you got them kinda numbers out of that tiny *** camshaft. I figure no matter how much heads you threw at it you'd be lucky with 225 wheel horsepower quite. Once again you've proven the common nomenclature incorrect awesome tuning fast. nice work.
02-15-2008, 09:45 PM
#13
Re: 300 HP Bolt-on L03 TBI
"The world's best cam combined with a poor set of heads will produce an engine that's a dog. But bolt on a set of great heads even with a poor cam, and that engine will still make great power."
Just goes to show how good the 059 Vortec 305 heads actually are, even though everyone bashes them because of the 1.84 intake.
02-15-2008, 10:10 PM
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Car: 90 Firebird Formula
Engine: LO3
Transmission: T5
Axle/Gears: 3.08 one wheel peel
Re: 300 HP Bolt-on L03 TBI
Does anybody know the GM part number for the 059 heads?
I have seen like 4 different castings of SBC vortec heads on ebay used. I don't know the differece between them, except that the 059's were for a 305.
However, looking at Summit and Jegs, I can only find ONE vortec new. That same set is on GMpartsdirect for like $10 more. If I could figure out the GM part numbers, I bet all the Vortec heads would be available new on GMPD.
I have seen like 4 different castings of SBC vortec heads on ebay used. I don't know the differece between them, except that the 059's were for a 305.
However, looking at Summit and Jegs, I can only find ONE vortec new. That same set is on GMpartsdirect for like $10 more. If I could figure out the GM part numbers, I bet all the Vortec heads would be available new on GMPD.
02-15-2008, 10:45 PM
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Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
Re: 300 HP Bolt-on L03 TBI
Does anybody know the GM part number for the 059 heads?
I have seen like 4 different castings of SBC vortec heads on ebay used. I don't know the differece between them, except that the 059's were for a 305.
However, looking at Summit and Jegs, I can only find ONE vortec new. That same set is on GMpartsdirect for like $10 more. If I could figure out the GM part numbers, I bet all the Vortec heads would be available new on GMPD.
I have seen like 4 different castings of SBC vortec heads on ebay used. I don't know the differece between them, except that the 059's were for a 305.
However, looking at Summit and Jegs, I can only find ONE vortec new. That same set is on GMpartsdirect for like $10 more. If I could figure out the GM part numbers, I bet all the Vortec heads would be available new on GMPD.
They have a 58cc chamber and run 1.84/1.50" valves, with the same ports as the EQ 350 vortec heads which flow better than the stock Vortecs. They also have more material where it matters for porting.
http://www.eqcylinderheads.com/photo-docs/ch305a.html
02-15-2008, 10:59 PM
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Car: 90 Firebird Formula
Engine: LO3
Transmission: T5
Axle/Gears: 3.08 one wheel peel
Re: 300 HP Bolt-on L03 TBI
Wow those dont look too bad... $320 a pop isnt much more than the GM heads. Are they only available bare?
02-16-2008, 08:12 AM
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Car: 91 Trans am
Engine: built 360 TBI
Transmission: built 700r4
Axle/Gears: 10bolt/3.23
Re: 300 HP Bolt-on L03 TBI
I would look at EngineQuest CH305A heads, they are new, improved castings of the 059s.
They have a 58cc chamber and run 1.84/1.50" valves, with the same ports as the EQ 350 vortec heads which flow better than the stock Vortecs. They also have more material where it matters for porting.
http://www.eqcylinderheads.com/photo-docs/ch305a.html
They have a 58cc chamber and run 1.84/1.50" valves, with the same ports as the EQ 350 vortec heads which flow better than the stock Vortecs. They also have more material where it matters for porting.
http://www.eqcylinderheads.com/photo-docs/ch305a.html
Did u tune it using the stock ECM?
I have already installed a lt1 cam, is it possible hp - rpm range, will be to high for a streat lo3?
Sorry for all the questions but I would really like to find a stock looking combination for my lo3, that makes excellent power below 4500 rpm that doesent require machine work.
02-16-2008, 08:46 AM
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Car: 90 Firebird Formula
Engine: LO3
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Axle/Gears: 3.08 one wheel peel
Re: 300 HP Bolt-on L03 TBI
Me too, I am looking for a good daily driver LO3 top end, that I can paint black, and it will make good power, but at first apparance it will look like a completely stock motor. People wont know what hit them!
Those EngineQuest heads look nice, and I do believe the whole point of getting a 305 head is it comes with a smaller chamber, like 58cc, so that you shouldnt have to mill it down. I would just be hesitant to spend that much on heads that didnt even come with valves or anything.
The other problem, is, dont you need to modify the vortec heads to take the lift from the LT1 cam?
Those EngineQuest heads look nice, and I do believe the whole point of getting a 305 head is it comes with a smaller chamber, like 58cc, so that you shouldnt have to mill it down. I would just be hesitant to spend that much on heads that didnt even come with valves or anything.
The other problem, is, dont you need to modify the vortec heads to take the lift from the LT1 cam?
02-16-2008, 09:04 AM
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Car: 91 Trans am
Engine: built 360 TBI
Transmission: built 700r4
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Re: 300 HP Bolt-on L03 TBI
[QUOTE=The other problem, is, dont you need to modify the vortec heads to take the lift from the LT1 cam?[/QUOTE]
I really hope your wrong on that one. If not I will really regret the lt1 cam conversion.
I really hope your wrong on that one. If not I will really regret the lt1 cam conversion.
02-16-2008, 09:18 AM
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Car: 90 Firebird Formula
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Axle/Gears: 3.08 one wheel peel
Re: 300 HP Bolt-on L03 TBI
Why, the LT1 cam is about a mild as they get, unless you wanted to swap in the stock peanut cam like he did.
02-16-2008, 09:30 AM
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Car: 89 iroc-z
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Transmission: wc-t5
Axle/Gears: 10 bolt 3.08 posi (4 now)
Re: 300 HP Bolt-on L03 TBI
oh there is plenty more mild camshafts than the lt1 cam but, true it is tiny in my estimation. just under .450 lift at rockers. with insanely low durations.
anything over .460 lift at rockers i would be weary of. Some can get by with over
.480 but, you need to check it for clearence 4 sure.
anyways i'm going to be running a crane 2032 in my 305, it's just .452/.465 lift with 1.5s but, i'll be using 1.6s so i'm going to use .050 locks, and .050 spring shims just in case so i dont have to worry about it, know what i mean?
something to be said for peice of mind for sure.
anything over .460 lift at rockers i would be weary of. Some can get by with over
.480 but, you need to check it for clearence 4 sure.
anyways i'm going to be running a crane 2032 in my 305, it's just .452/.465 lift with 1.5s but, i'll be using 1.6s so i'm going to use .050 locks, and .050 spring shims just in case so i dont have to worry about it, know what i mean?
something to be said for peice of mind for sure.
02-16-2008, 10:54 AM
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Car: 90 Firebird Formula
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Axle/Gears: 3.08 one wheel peel
Re: 300 HP Bolt-on L03 TBI
oh there is plenty more mild camshafts than the lt1 cam but, true it is tiny in my estimation. just under .450 lift at rockers. with insanely low durations.
anything over .460 lift at rockers i would be weary of. Some can get by with over
.480 but, you need to check it for clearence 4 sure.
anything over .460 lift at rockers i would be weary of. Some can get by with over
.480 but, you need to check it for clearence 4 sure.
anyways i'm going to be running a crane 2032 in my 305, it's just .452/.465 lift with 1.5s but, i'll be using 1.6s so i'm going to use .050 locks, and .050 spring shims just in case so i dont have to worry about it, know what i mean?
something to be said for peice of mind for sure.
something to be said for peice of mind for sure.
The other thing I was wondering about though, is maybe something off-brand like a Summit Racing cam or something. They have those things real cheep, and I am sure they have some milder ones like the LT1 or something, right?
02-16-2008, 11:31 AM
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Car: 89 iroc-z
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Re: 300 HP Bolt-on L03 TBI
Does this mean that an LT1 cam sould be fine paired with a set of vortec heads, with the factory springs and rockers on the vortecs?
yes sir, as long as you are using a 1.5 ratio rocker arm it will be fine. (1.5 ratio is factory on all sbc's that i know of unless were talking aftermarket).
Ive never actually worked on a set of heads, so you are a little over my head there (no pun intended). I dont know what locks and shims are. I looked that cam up on summit, looks like a great choice for a mild top end. However, it costs and arm and a leg. From what I read, keeping a low LSA is the key to being able to tune the computer for the camshaft.
this is much more simple than it sounds. on a set of heads you of course have your springs set in first in the factory spring perches next to the rocker studs right? (thats the bowl like cut out in the head casting). Above that you have a retainer, which is a round disk shaped washer that sits over top of the spring (think of it as a spring hat). Then of course you have is called a valve lock. It does just what the name implys. A valve lock is wierd shaped tiny little peice of metal that fits in a groove cut at the top of the valve. when assembling you compress your spring with a spring compressor that fits over top of the spring hat (retainer), then you use the tiny little machined locks and put them in the groove found on the top of the valve while slowly uncompressing the spring until the spring pressure exerted is enough to get the machined locks stuck in place. It's as easy as that.
The other thing I was wondering about though, is maybe something off-brand like a Summit Racing cam or something. They have those things real cheep, and I am sure they have some milder ones like the LT1 or something, right?
yes sir, as long as you are using a 1.5 ratio rocker arm it will be fine. (1.5 ratio is factory on all sbc's that i know of unless were talking aftermarket).
Ive never actually worked on a set of heads, so you are a little over my head there (no pun intended). I dont know what locks and shims are. I looked that cam up on summit, looks like a great choice for a mild top end. However, it costs and arm and a leg. From what I read, keeping a low LSA is the key to being able to tune the computer for the camshaft.
this is much more simple than it sounds. on a set of heads you of course have your springs set in first in the factory spring perches next to the rocker studs right? (thats the bowl like cut out in the head casting). Above that you have a retainer, which is a round disk shaped washer that sits over top of the spring (think of it as a spring hat). Then of course you have is called a valve lock. It does just what the name implys. A valve lock is wierd shaped tiny little peice of metal that fits in a groove cut at the top of the valve. when assembling you compress your spring with a spring compressor that fits over top of the spring hat (retainer), then you use the tiny little machined locks and put them in the groove found on the top of the valve while slowly uncompressing the spring until the spring pressure exerted is enough to get the machined locks stuck in place. It's as easy as that.
The other thing I was wondering about though, is maybe something off-brand like a Summit Racing cam or something. They have those things real cheep, and I am sure they have some milder ones like the LT1 or something, right?
i'll have a lb9 5 speed camshaft for sale come spring time if interested (i'll let you have it for 25 bux if u want it).
if you want something a bit bigger than that pm me i can help you decide on what fits your application best.
02-16-2008, 12:00 PM
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Car: 90 Firebird Formula
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Re: 300 HP Bolt-on L03 TBI
Well, when I finally decide to go ahead with my project, I will keep that in mind. I think tho, if I am gonna do all the work to tear off the heads, and replace all this different stuff, and do a cam swap, I might as well get some beefy parts.
02-19-2008, 07:35 PM
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Car: 92 RS heritage addition
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Re: 300 HP Bolt-on L03 TBI
does anyone know if the crane 109821 roller with .509 lift will work on a stock L03 if the heads are setup to fit (springs valves ect for the lift)
02-19-2008, 08:13 PM
#27
Re: 300 HP Bolt-on L03 TBI
255 RWHP @ 4,900
310 RWTQ @ 3,200
310 RWTQ @ 3,200
Get a L98 or LT1 cam and watch you hit 270's
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