LO3 rebuild (HP estimates?)
05-29-2013, 11:42 PM
#53
Re: LO3 rebuild (HP estimates?)
Let's recap:
-Worse heads than an L98
-40 less cubes than an L98 (assuming a 310)
- Cam is the only advantage you have:
Yours: .485/.495 213/217 114 LSA
L98: .413/.428 202/207 114.5
Im not saying that isnt a big difference, it is, but thats still a pretty small cam. I'd say 270-280 hp is reasonable if you were to put that cam into an L98. But you're talking about taking an engine that makes 170fwhp, and using the same displacement and cylinder heads, and adding a cam to make an extra 100hp when the cam is still relatively small (although I think its a pretty good choice, it will definitely maximize what you have without interfering with your drivability too much).
-Worse heads than an L98
-40 less cubes than an L98 (assuming a 310)
- Cam is the only advantage you have:
Yours: .485/.495 213/217 114 LSA
L98: .413/.428 202/207 114.5
Im not saying that isnt a big difference, it is, but thats still a pretty small cam. I'd say 270-280 hp is reasonable if you were to put that cam into an L98. But you're talking about taking an engine that makes 170fwhp, and using the same displacement and cylinder heads, and adding a cam to make an extra 100hp when the cam is still relatively small (although I think its a pretty good choice, it will definitely maximize what you have without interfering with your drivability too much).
06-01-2013, 03:37 PM
#54
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Re: LO3 rebuild (HP estimates?)
Let's recap:
-Worse heads than an L98
-40 less cubes than an L98 (assuming a 310)
- Cam is the only advantage you have:
Yours: .485/.495 213/217 114 LSA
L98: .413/.428 202/207 114.5
Im not saying that isnt a big difference, it is, but thats still a pretty small cam. I'd say 270-280 hp is reasonable if you were to put that cam into an L98. But you're talking about taking an engine that makes 170fwhp, and using the same displacement and cylinder heads, and adding a cam to make an extra 100hp when the cam is still relatively small (although I think its a pretty good choice, it will definitely maximize what you have without interfering with your drivability too much).
-Worse heads than an L98
-40 less cubes than an L98 (assuming a 310)
- Cam is the only advantage you have:
Yours: .485/.495 213/217 114 LSA
L98: .413/.428 202/207 114.5
Im not saying that isnt a big difference, it is, but thats still a pretty small cam. I'd say 270-280 hp is reasonable if you were to put that cam into an L98. But you're talking about taking an engine that makes 170fwhp, and using the same displacement and cylinder heads, and adding a cam to make an extra 100hp when the cam is still relatively small (although I think its a pretty good choice, it will definitely maximize what you have without interfering with your drivability too much).
The stock L03 makes a substantial amount more power, simply changing the intake manifold, installing headers, and opening up the exhaust with the correct tuning.
06-01-2013, 04:15 PM
#55
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Re: LO3 rebuild (HP estimates?)
TPI heads are HORRIBLE, the TBI heads are actually better. I lost less than 10 HP at 5,500 rpm and gained nearly 30 ft/lbs of torque, swapping stock 081s for stock 187s when one of my 081s cracked. I was quicker and ran the same MPH with TBI heads. I had a 216/216 @ .050 Crane 100052 Energizer cam and 1.6:1 rockers on both.
The stock L03 makes a substantial amount more power, simply changing the intake manifold, installing headers, and opening up the exhaust with the correct tuning.
The stock L03 makes a substantial amount more power, simply changing the intake manifold, installing headers, and opening up the exhaust with the correct tuning.
06-01-2013, 04:39 PM
#56
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Re: LO3 rebuild (HP estimates?)
Let's recap:
-Worse heads than an L98
-40 less cubes than an L98 (assuming a 310)
- Cam is the only advantage you have:
Yours: .485/.495 213/217 114 LSA
L98: .413/.428 202/207 114.5
Im not saying that isnt a big difference, it is, but thats still a pretty small cam. I'd say 270-280 hp is reasonable if you were to put that cam into an L98. But you're talking about taking an engine that makes 170fwhp, and using the same displacement and cylinder heads, and adding a cam to make an extra 100hp when the cam is still relatively small (although I think its a pretty good choice, it will definitely maximize what you have without interfering with your drivability too much).
-Worse heads than an L98
-40 less cubes than an L98 (assuming a 310)
- Cam is the only advantage you have:
Yours: .485/.495 213/217 114 LSA
L98: .413/.428 202/207 114.5
Im not saying that isnt a big difference, it is, but thats still a pretty small cam. I'd say 270-280 hp is reasonable if you were to put that cam into an L98. But you're talking about taking an engine that makes 170fwhp, and using the same displacement and cylinder heads, and adding a cam to make an extra 100hp when the cam is still relatively small (although I think its a pretty good choice, it will definitely maximize what you have without interfering with your drivability too much).
06-02-2013, 02:38 PM
#57
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Re: LO3 rebuild (HP estimates?)
I'm having trouble verifying that this is the correct rev kit for the aplication .. Others specify " mechanical roller "" retrofit hydraulic " etc. .. Is this the correct kit ?
http://m.summitracing.com/parts/cca-4000
http://m.summitracing.com/parts/cca-4000
06-03-2013, 01:37 AM
#58
Re: LO3 rebuild (HP estimates?)
TPI heads are HORRIBLE, the TBI heads are actually better. I lost less than 10 HP at 5,500 rpm and gained nearly 30 ft/lbs of torque, swapping stock 081s for stock 187s when one of my 081s cracked. I was quicker and ran the same MPH with TBI heads. I had a 216/216 @ .050 Crane 100052 Energizer cam and 1.6:1 rockers on both.
The stock L03 makes a substantial amount more power, simply changing the intake manifold, installing headers, and opening up the exhaust with the correct tuning.
The stock L03 makes a substantial amount more power, simply changing the intake manifold, installing headers, and opening up the exhaust with the correct tuning.
https://www.thirdgen.org/forums/tbi/...heads-why.html
Compare the green to the purple...
https://www.thirdgen.org/forums/post...821-post1.html
But since the above chart doesnt reference iron heads, here are numbers for iron L98 heads, and ironically, fast355, you are the source... ?
305 heads, 1.84"/1.50"
187 iron LO3 head: 165 intake; 140 exh (Fast355)
081 iron head: 195 intake; 110 exh (ME Leigh)
187 iron LO3 head: 165 intake; 140 exh (Fast355)
081 iron head: 195 intake; 110 exh (ME Leigh)
https://www.thirdgen.org/forums/post...367-post2.html
This is one of the more interesting ones, because he tested both heads back to back on the same bench.
I got 62/49 at .100, 112/91 at .200, 138/125 at .300, 147/139 at .400, and 150/142 at max lift (about .480).
For the L98 head I got 56/44 at .100, 113/96 at .200, 150/129 at .300, 173/139 at .400, and 179/142 at max lift (again, about .480).
For the L98 head I got 56/44 at .100, 113/96 at .200, 150/129 at .300, 173/139 at .400, and 179/142 at max lift (again, about .480).
083: 150/142 @ .480
193: 179/142 @ .480
These are 350 heads, and not the 305 heads, but they're supposed to be pretty close. And the 193's in this case didnt show any exhaust flow advantage. Flowbenches are susceptible to a lot of weird inconsistencies from one test to another, but swirl ports ALWAYS have HORRENDOUS intake flow precisely because of those swirl ramps. Port them and you're liable to mess with the cross sectional area and increase your port volume enough to ruin your throttle response.
I dont see how you're going to get more power out of swirlports except in very unique scenarios.
Also I'm not just adding a cam ... I'm also going .030 over which I know ain't much but it helps unshroud the valves at high lift .. And installing flat top pistons which with some slight milling of the heads should get me 10:1+ compression from the factory 9.3:1 , then Porting heads and installing new stainless swirl polished & back cut valves , installing a much much better intake , headers, CFM tech TB , and my custom homemade true CAI, also the valve train is much lighter than factory with the rev kit taking the lifters out o the equation and the spring retainers being 3 grams lighter on intake side and 18 grams on exhaust which shoul help some .. Plus the 1.6 full roller rockers should help get that cam up to around .528 lift with more duration from seat to seat .. And yeah I know y not just build a 350 ... Because everyone has a 350 that's why ...
06-01-2013 05:15 PM
06-01-2013 05:15 PM
You're going to get as much power as is possible out of those heads, that much is obvious. But why make things so difficult on yourself? 081's and 416's are known to be excellent heads. I have first hand seen a 305 with 416's do low 12's on pump gas. And he did with a flat tappet cam. And 416's came on every piece of crap LG4 out there. 081's are the exact same head, just set up for self aligning rockers and centerbolt valve covers. Far superior to swirlports according to actual numbers. You can port your swirlies if you want, but why not port some 416's or 081's? Those things respond GREAT to porting. Like I said, I've actually seen 300hp 305's with those. Save the money on the rev kit, you probably wont be going past 6000 RPMs so it wont help you much. Use that money and buy some 416's! Port those! They're good!
Last edited by InfernalVortex; 06-03-2013 at 01:46 AM.
06-05-2013, 10:52 PM
#59
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Re: LO3 rebuild (HP estimates?)
You are pretty much the only person I have EVER seen make TBI heads work for anything beyond boat anchors. 083 heads are fine. They have a proven track record. If they were that bad then the General would have used the TBI heads on the L98's. A little more exhaust flow is not going to make a given head vastly superior.
https://www.thirdgen.org/forums/tbi/...heads-why.html
Compare the green to the purple...
https://www.thirdgen.org/forums/post...821-post1.html
But since the above chart doesnt reference iron heads, here are numbers for iron L98 heads, and ironically, fast355, you are the source... ?
https://www.thirdgen.org/forums/post...367-post2.html
This is one of the more interesting ones, because he tested both heads back to back on the same bench.
Or...
083: 150/142 @ .480
193: 179/142 @ .480
These are 350 heads, and not the 305 heads, but they're supposed to be pretty close. And the 193's in this case didnt show any exhaust flow advantage. Flowbenches are susceptible to a lot of weird inconsistencies from one test to another, but swirl ports ALWAYS have HORRENDOUS intake flow precisely because of those swirl ramps. Port them and you're liable to mess with the cross sectional area and increase your port volume enough to ruin your throttle response.
I dont see how you're going to get more power out of swirlports except in very unique scenarios.
All the bolt-ons are pretty much implied. I expect headers and intake etc on a motor that gets rebuilt for performance. But I've got to ask, why make the investment in valves and not in cylinder heads? The TBI intake isnt great, but it suits the RPM range swirl port heads work in. All those things you mention still arent going to account for a 100hp increase over stock. The best thing you have going for you is that you have a very aggressive, but short duration cam. I dont think you're going to hit stock L98 numbers, but you may get very close.
You're going to get as much power as is possible out of those heads, that much is obvious. But why make things so difficult on yourself? 081's and 416's are known to be excellent heads. I have first hand seen a 305 with 416's do low 12's on pump gas. And he did with a flat tappet cam. And 416's came on every piece of crap LG4 out there. 081's are the exact same head, just set up for self aligning rockers and centerbolt valve covers. Far superior to swirlports according to actual numbers. You can port your swirlies if you want, but why not port some 416's or 081's? Those things respond GREAT to porting. Like I said, I've actually seen 300hp 305's with those. Save the money on the rev kit, you probably wont be going past 6000 RPMs so it wont help you much. Use that money and buy some 416's! Port those! They're good!
https://www.thirdgen.org/forums/tbi/...heads-why.html
Compare the green to the purple...
https://www.thirdgen.org/forums/post...821-post1.html
But since the above chart doesnt reference iron heads, here are numbers for iron L98 heads, and ironically, fast355, you are the source... ?
https://www.thirdgen.org/forums/post...367-post2.html
This is one of the more interesting ones, because he tested both heads back to back on the same bench.
Or...
083: 150/142 @ .480
193: 179/142 @ .480
These are 350 heads, and not the 305 heads, but they're supposed to be pretty close. And the 193's in this case didnt show any exhaust flow advantage. Flowbenches are susceptible to a lot of weird inconsistencies from one test to another, but swirl ports ALWAYS have HORRENDOUS intake flow precisely because of those swirl ramps. Port them and you're liable to mess with the cross sectional area and increase your port volume enough to ruin your throttle response.
I dont see how you're going to get more power out of swirlports except in very unique scenarios.
All the bolt-ons are pretty much implied. I expect headers and intake etc on a motor that gets rebuilt for performance. But I've got to ask, why make the investment in valves and not in cylinder heads? The TBI intake isnt great, but it suits the RPM range swirl port heads work in. All those things you mention still arent going to account for a 100hp increase over stock. The best thing you have going for you is that you have a very aggressive, but short duration cam. I dont think you're going to hit stock L98 numbers, but you may get very close.
You're going to get as much power as is possible out of those heads, that much is obvious. But why make things so difficult on yourself? 081's and 416's are known to be excellent heads. I have first hand seen a 305 with 416's do low 12's on pump gas. And he did with a flat tappet cam. And 416's came on every piece of crap LG4 out there. 081's are the exact same head, just set up for self aligning rockers and centerbolt valve covers. Far superior to swirlports according to actual numbers. You can port your swirlies if you want, but why not port some 416's or 081's? Those things respond GREAT to porting. Like I said, I've actually seen 300hp 305's with those. Save the money on the rev kit, you probably wont be going past 6000 RPMs so it wont help you much. Use that money and buy some 416's! Port those! They're good!
06-06-2013, 10:23 AM
#60
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Re: LO3 rebuild (HP estimates?)
Why not just get a set of vortec heads + intake and be done with it.
06-07-2013, 01:52 PM
#61
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Re: LO3 rebuild (HP estimates?)
The LO3 heads are temporary ... Sometime next year prolly winter .. Ill prolly be going to the trick flow 170cc 58cc chamber heads if I don't like how it runs as is ..
http://m.youtube.com/#/watch?v=qZ8WeMGWUj4
Here's what I got goin so far ^
http://m.youtube.com/#/watch?v=qZ8WeMGWUj4
Here's what I got goin so far ^
06-27-2013, 12:59 AM
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Re: LO3 rebuild (HP estimates?)
Let's recap:
-Worse heads than an L98
-40 less cubes than an L98 (assuming a 310)
- Cam is the only advantage you have:
Yours: .485/.495 213/217 114 LSA
L98: .413/.428 202/207 114.5
Im not saying that isnt a big difference, it is, but thats still a pretty small cam. I'd say 270-280 hp is reasonable if you were to put that cam into an L98. But you're talking about taking an engine that makes 170fwhp, and using the same displacement and cylinder heads, and adding a cam to make an extra 100hp when the cam is still relatively small (although I think its a pretty good choice, it will definitely maximize what you have without interfering with your drivability too much).
-Worse heads than an L98
-40 less cubes than an L98 (assuming a 310)
- Cam is the only advantage you have:
Yours: .485/.495 213/217 114 LSA
L98: .413/.428 202/207 114.5
Im not saying that isnt a big difference, it is, but thats still a pretty small cam. I'd say 270-280 hp is reasonable if you were to put that cam into an L98. But you're talking about taking an engine that makes 170fwhp, and using the same displacement and cylinder heads, and adding a cam to make an extra 100hp when the cam is still relatively small (although I think its a pretty good choice, it will definitely maximize what you have without interfering with your drivability too much).
-305 block,
-Trickflow TFS23 heads which really flow compared to stock
-LT1 Cam with 1,6 rollers
-590 CFM TBI with 68 injectros with slightly increased fuel pressure
-TPI fuel pump
-Edelbrock performer intake bored to 50 mm
-Headers and dual exhaust with cats
-EBL
Logging with EBL gave me following results:
In local finnish board people judged me that there is error between travelled distance and time.
Whad do you think? EBL speed readings at least should be somewhat correct. (according to radar and GPS)
06-27-2013, 11:09 AM
#63
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Re: LO3 rebuild (HP estimates?)
Idk it prolly within .3-.5 seconds on elapsed time ... But I ran a 9.82 in the 1/8th @73 MPH with a pretty much bone stock LO3 engine .. 1.6 rockers , headers , exhaust , & CFM Tech TB ...
08-01-2013, 09:43 PM
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Re: LO3 rebuild (HP estimates?)
Well guys I ran out of $ and couldn't get my machine work done .. So that is why there hasn't been any updates here ... So I've decided to ditch the idea of spending 3-400$ getting the stock heads compatible and am going to sell the valve springs and retainers I had and just get a set of the assebled trick flow super 23 175cc heads ! ... And save my self Alot a trouble .. So everything else will be the same as before except the heads ... So with that said I am expecting to see 325+ HP at the crank ( hopefully upwards of 350) lol ... But I have a question I hope someone can help with .... What should I do with my current timing table in EBL seeing as I'm using diff heads ? The car ran 9.800 in the 1/8th with a mostly stock Lo3 so I'd say I had it tuned quite well ... But idk why to do with the timing tables ! Please help ! I should have this thing running within a month or two at most !!!!! Any new HP estimates for me with the head change ? Thanks to all !!! Nate
08-02-2013, 06:47 AM
#65
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Re: LO3 rebuild (HP estimates?)
Well guys I ran out of $ and couldn't get my machine work done .. So that is why there hasn't been any updates here ... So I've decided to ditch the idea of spending 3-400$ getting the stock heads compatible and am going to sell the valve springs and retainers I had and just get a set of the assebled trick flow super 23 175cc heads ! ... And save my self Alot a trouble .. So everything else will be the same as before except the heads ... So with that said I am expecting to see 325+ HP at the crank ( hopefully upwards of 350) lol ... But I have a question I hope someone can help with .... What should I do with my current timing table in EBL seeing as I'm using diff heads ? The car ran 9.800 in the 1/8th with a mostly stock Lo3 so I'd say I had it tuned quite well ... But idk why to do with the timing tables ! Please help ! I should have this thing running within a month or two at most !!!!! Any new HP estimates for me with the head change ? Thanks to all !!! Nate
08-02-2013, 03:38 PM
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Re: LO3 rebuild (HP estimates?)
Thanks fast ! I guess I'll start with the one with least timing .. I'd hate to pop a ring land in the first hour of running lol ... Everyone says the hyper pistons don't like pinging at all !
08-04-2013, 10:21 AM
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Re: LO3 rebuild (HP estimates?)
Any suggestions on intstalled cam timing ? I'm thinking about installing cam in on a 108 ICL? Instead of the ground in 110 ICL ? Any info on this subject in general would be great ... My timing set is adjustable 8* adv. or ret. ... What are the effects of installing a couple deg. Adv.? Ret. ? 4* ? 6*? 8* !!? Thanks !
08-04-2013, 01:57 PM
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Re: LO3 rebuild (HP estimates?)
Any suggestions on intstalled cam timing ? I'm thinking about installing cam in on a 108 ICL? Instead of the ground in 110 ICL ? Any info on this subject in general would be great ... My timing set is adjustable 8* adv. or ret. ... What are the effects of installing a couple deg. Adv.? Ret. ? 4* ? 6*? 8* !!? Thanks !
If you're going with the Trick Flows I don't think you'd need to advance that cam to bring the power band down as they should have plenty of flow for what you need. I'd only retard it if you want to shift higher. I'd probably try straight up as a starting point.
08-04-2013, 02:14 PM
#69
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Re: LO3 rebuild (HP estimates?)
Any suggestions on intstalled cam timing ? I'm thinking about installing cam in on a 108 ICL? Instead of the ground in 110 ICL ? Any info on this subject in general would be great ... My timing set is adjustable 8* adv. or ret. ... What are the effects of installing a couple deg. Adv.? Ret. ? 4* ? 6*? 8* !!? Thanks !
For a mild street motor, I like the ICL about 4* less than the LSA. 4-5* seems to work well for me. If its a 110 LSA you want a 106 LSA and if its a 114 LSA you want a 110 lCL. I think figured this out years ago and almost all GM cams are setup this way. My vortec cam for example is a 111 LSA on a 106 ICL.
Last edited by Fast355; 08-04-2013 at 02:18 PM.
08-04-2013, 08:16 PM
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Re: LO3 rebuild (HP estimates?)
Alright cool ... And thanks again ! .. I think I'll just install it straight up ... Cam is 114 LSA and 110 ICL .. I'm so freakin ready to get this build done and eat some stangs and a few mild 350's with a 305 ! Muuaahhahahaha ( evil laugh ) first on list is my dads 08' GT/CS ... Im wanting my shift point @ around 6000rpm or slightly higher ... With a shift point at around 43-4500 (stock) I was grabbing 4 gears in the 1/8th and trapping about 4000 in 4th with 4.10's and T-5 Trans of course ... I wish RBob would create a timing table to start with specifically for these heads !!! Any suggestions on some things I should change in the tune before initial firing ? Like what should I do with VE ? To get it slightly closer ? I'm also switching to 68# injectors from the 55's .. I know to change my BPC tables and change timing for the head swap but idk what to do with VE or how much to increase the fuel delivered ???
08-05-2013, 07:49 AM
#71
Re: LO3 rebuild (HP estimates?)
Originally Posted by 1991sleeper
I wish RBob would create a timing table to start with specifically for these heads !!! Any suggestions on some things I should change in the tune before initial firing?
08-05-2013, 09:30 AM
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Re: LO3 rebuild (HP estimates?)
Cool man ... I have my initial set at 6* I believe but that was with the stock engine ill have to play around n see what it likes , I was thinking prolly around 10* or so with the new cam and heads ... I think I'll email trick flow and see what the reccomend for total timing ... I had 98% of my timing in by 2800 with the stock lo3 (tb,CAI,1.6RR,headers,exhaust) , pulled me to a 9.80 @ 72-73mph with 2.05-2.10 60's ... Any suggestions on the VE table ? I read somewhere that better flowing engines (heads,cam) like a little less at idle and more through the "power band" of the cam ... Which the adv. power band is 1000-5000 but that's on a 350 so I was thinking it would be more like 1500-5800 or so and idle around 750rpm easily
08-05-2013, 09:40 AM
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Axle/Gears: 4.10
Re: LO3 rebuild (HP estimates?)
Streetlethal ! If u don't Mind what kinda power or ET r u putting down ? Are u TBI ? Forged internals ? I know u prolly have one of the fastest 305's here if not THE fastest ... Next in line would prolly b FAst355 & Robertfrank for the NA cars lol... I may go with a couple pounds with a wynjammer here in a few years ... But with around 10:1 I prolly won't b able to put much on it Mabey 5-6psi ? (no boost guru here) or mabey a 75-100 shot on the bottle just in case .. Who would be a good company to send my heads to to get ported ? N how much does that usually cost ? I would do it but this ain't gonna be no set of free LO3 heads ... 240cfm @ .500 out the box has alot a room for improvement ! Hehehaho
08-05-2013, 07:05 PM
#74
Re: LO3 rebuild (HP estimates?)
Originally Posted by 1991sleeper
Streetlethal ! If u don't Mind what kinda power or ET r u putting down ? Are u TBI ? Forged internals ? I know u prolly have one of the fastest 305's here if not THE fastest ... Next in line would prolly b FAst355 & Robertfrank for the NA cars lol...
Very first start without the EBL, whistling/vacuum noise is from the IAC...
... still without the EBL, was running the $8D code during this video.
Last edited by Street Lethal; 08-05-2013 at 07:13 PM. Reason: Added Videos
08-06-2013, 06:59 AM
#75
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Car: 1991 firebird
Engine: TBI 305 (built)
Transmission: T5
Axle/Gears: 4.10
Re: LO3 rebuild (HP estimates?)
Damn . So what the hell u do to that tuned port system? Lol .... 800HP 305 ! F'in smoke on that 350/383/400 guys haha ..... ... Boat anchors ha .... I'd like to eventually have all forged internals on my 305 might even make a 334 ... If so I believe id go with the wynjammer set up @ about 10psi ... My # 1 choice would be an all forged 327 roller @ about 500hp @ 7500 + N/A but the short block I want is 6k+ lol ... .....
My dad has a BB427 with stock forged internals from 1968 and I've seen that thing on 8k from the back seat several times ,so I know a 327 could do the same easily ...
My dad has a BB427 with stock forged internals from 1968 and I've seen that thing on 8k from the back seat several times ,so I know a 327 could do the same easily ...
08-06-2013, 07:11 AM
#76
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Car: 1991 firebird
Engine: TBI 305 (built)
Transmission: T5
Axle/Gears: 4.10
Re: LO3 rebuild (HP estimates?)
I just put all my info in desktop dyno .." I WAS EXTREMELY CONSERVATIVE "... I used solid flat tappet because roller just seems like it gives way too much increase , no overbore, I used airflow #'s from trick flow heads, 9.5:1, 600cfm@1.5, dual plane , small tubesw/ mufflers , and my cam specs , 380hp@7500 and 330ft.lbs@ 5000 ... But I ain't gonna be turning that high so 366hp@ 6000
08-06-2013, 08:37 AM
#77
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Car: 1991 firebird
Engine: TBI 305 (built)
Transmission: T5
Axle/Gears: 4.10
Re: LO3 rebuild (HP estimates?)
I goofed ! I had the cam specs @ 50 With advertised duration numbers so I changed that and the power band looks alot more like it should b ... 340 HP @ 5500 & 378 ft.lbs. @ 3500 and that's alot more conservative tan what I'm actually building .. That's @ 9:1 , no overbore , small headers w mufflers ( I have a dump ) , and that's with solid lifter no roller .... I I change nothing but the lifter from solid to roller I get 346 @ 5500 & 393 @ 3500-4k .... What y'all think?
08-19-2013, 05:45 PM
#78
08-23-2013, 11:39 PM
#82
Re: LO3 rebuild (HP estimates?)
If done properly is a caveat that kind of applies to everything. That said, you'd be a fool to not spend the money on that. Factory engines are balanced (a completely different, far less labor intensive method due to the realities of mass production). You dont want to invest in a rebuilt engine with a new bottom end and then not balance it. It's easy to say you dont care, but you're raelly shooting yourself and your investment in the foot by not taking care of that.
08-24-2013, 12:06 AM
#83
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Car: 1991 firebird
Engine: TBI 305 (built)
Transmission: T5
Axle/Gears: 4.10
Re: LO3 rebuild (HP estimates?)
It's the stock bottom end .. Just new pistons and arp bolts ... EVERY BOLT in the engine is brand new from arp even the oil pump stud ! .... I'm also thinking about sending by TFS heads somewhere to get ported ! Any places u guys know of ? Also I believe after a couple years I will be going with a larger cam after getting the hang o tuning this setup.... And i am definitely gettin it balanced by walker engine service in Memphis TN .... Any new HP estimates with the change in head selection ? I believe my CR will end up being closer to 10.5:1 now ... And thanks for all the replies !
08-24-2013, 07:09 PM
#85
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Car: 1991 firebird
Engine: TBI 305 (built)
Transmission: T5
Axle/Gears: 4.10
Re: LO3 rebuild (HP estimates?)
I am ... What kind of fuel pressure MAX will these injectors handle safely ? I have the CFM tech 68# er's ... No new HP Estimates with head swap ???!!!
08-25-2013, 01:33 AM
#86
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Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
Re: LO3 rebuild (HP estimates?)
The stock regulator is the main limiting component and I wouldn't run it over 35-40 psi. I have run the 68s at over 60 psi without issue.
08-25-2013, 01:38 AM
#88
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Car: 1991 firebird
Engine: TBI 305 (built)
Transmission: T5
Axle/Gears: 4.10
Re: LO3 rebuild (HP estimates?)
If my calculating is right I believe I'll only need around 35-37 psi anyway so I should still b in the green
08-26-2013, 12:04 AM
#89
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Car: 1991 firebird
Engine: TBI 305 (built)
Transmission: T5
Axle/Gears: 4.10
Re: LO3 rebuild (HP estimates?)
This wouldn't be added any time soon but I was gonna see what y'all thought anyway for possible future upgrades 2-3 years ... Anyone ever heard of these ppl ? Quality stuff ? Price looks good ... What is the HP/RPM limit of the factory rotating assembly "roughly" with good arp main studs & rod bolts installed ?
Anyway check out this kit ! Price looks good ... I was leaning towards a procharger by wynjammer but this is 1200$ cheaper lol even tho the procharger would b alot easier to set up and I wouldn't have to change my exhaust !
http://www.xs-power.com/gm-turbokits-1.htm
Anyway check out this kit ! Price looks good ... I was leaning towards a procharger by wynjammer but this is 1200$ cheaper lol even tho the procharger would b alot easier to set up and I wouldn't have to change my exhaust !
http://www.xs-power.com/gm-turbokits-1.htm
08-26-2013, 04:34 PM
#90
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Car: 1991 firebird
Engine: TBI 305 (built)
Transmission: T5
Axle/Gears: 4.10
Re: LO3 rebuild (HP estimates?)
Do y'all think it would b easier to pull the Trans and bolt it to the engine before installation or just put motor in by itself ? This is the first third gen motor I've pulled ! Remember this is a manual Trans car also I've never installed the engine on anything but auto cars ... I had to push the clutch in to get it to let loose of the motor when I pulled it ... This build is getting close guys ! Should be back in the car in less than 2 months ! Can't fF'n wait ! Ill be pretty much doubling my power and increasing my shift point by 2k rpm !
08-27-2013, 11:31 PM
#91
Re: LO3 rebuild (HP estimates?)
I know a lot of guys who like to do it together, but me personally I've always done it separate. Also I suggest you buy a power steering pump pulley puller and a torx bolt set and pull the accessory bracket off and pull the engine with the power steering pump left in the car.
You may want to consider leaving the bellhousing and clutch on the engine for the pull and the reinstall. I installed mine flywheel only, but it might be easier the other way... if you do it with the bellhousing on the engine let me know how it goes.
You may want to consider leaving the bellhousing and clutch on the engine for the pull and the reinstall. I installed mine flywheel only, but it might be easier the other way... if you do it with the bellhousing on the engine let me know how it goes.
Last edited by InfernalVortex; 08-27-2013 at 11:35 PM.
08-29-2013, 09:48 PM
#92
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Car: 1991 firebird
Engine: TBI 305 (built)
Transmission: T5
Axle/Gears: 4.10
Re: LO3 rebuild (HP estimates?)
The engine is already out and has been for a few months ... Just trying to find the easiest possible way .... I called the machine shop today for the third time in the last week so I am making a trip to Memphis Tn Saturday morning soon as I get off wrk ... And the machine wrk will be done by Wednesday next week .. I also ordered my Trick Flow heads today so they shoul be here soon ! Hope to start assembly next weekend ! And I will definitely be taking lots of pictures and keeping this thread updated along the way ... With videos of first crank and a track run after I get the tune dialed in ( with the help of all of u ) lol ... I had this thing tuned dang close to perfect before pulling the engine
(9.802 1/8th @ 73-74mph with stock engine & 1.6 rockers) ill also be installing the SFC's that have been laying in the floor before I head to the track ! I can't wait to get this thing done ... I know it prolly aint to exciting for y'all with ur 500hp + cars but I'm going from less than 200hp to 325-350+(hopefully) and I think it will be a fun/efficient street car and won't have to worry about getting smoked by a bicycle with a flat tire
Ill prolly need some serious help on my tune just to get it close at first .. Idk what to do with my timing tables with the head swap and the VE tables with the cam swap ? .. I also went from 55 to 68# injectors which I know to change my BPC stuff but why about injector correction/offsets etc. ? I was running 17 psi fp before and plan to start with 25 or so now ... I know I also need to reduce my ae stuff with the injector & FP increase .. Anything else y'all can think of or help with these above things possibly ? Fast355 I know u are a decent tuner
(9.802 1/8th @ 73-74mph with stock engine & 1.6 rockers) ill also be installing the SFC's that have been laying in the floor before I head to the track ! I can't wait to get this thing done ... I know it prolly aint to exciting for y'all with ur 500hp + cars but I'm going from less than 200hp to 325-350+(hopefully) and I think it will be a fun/efficient street car and won't have to worry about getting smoked by a bicycle with a flat tire
Ill prolly need some serious help on my tune just to get it close at first .. Idk what to do with my timing tables with the head swap and the VE tables with the cam swap ? .. I also went from 55 to 68# injectors which I know to change my BPC stuff but why about injector correction/offsets etc. ? I was running 17 psi fp before and plan to start with 25 or so now ... I know I also need to reduce my ae stuff with the injector & FP increase .. Anything else y'all can think of or help with these above things possibly ? Fast355 I know u are a decent tuner
08-30-2013, 12:05 AM
#93
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Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
Re: LO3 rebuild (HP estimates?)
Thing I can think of off hand is it will want a ton of extra timing with tha aluminum heads compared to the swirl ports. I think I have a ZZ4 head 305 with a healthy cam spark map hanging around still.
09-05-2013, 02:05 AM
#95
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Car: 1991 firebird
Engine: TBI 305 (built)
Transmission: T5
Axle/Gears: 4.10
Re: LO3 rebuild (HP estimates?)
Does anyone have a guestimate as to how much RPM the stock LO3 rods will handle ? I was planning on shifting between 6k&6500 but after some reading today I found out that 305 rods are NOT the same as 350 rods and are actually 30grams or so lighter than 350 rods ! ... I believe the rods are my weakest link here as I have arp wave lock rod bolts and arp main studs as well and the crank should easily handle 6500 seeing as I am having the bottom end spin balanced
09-05-2013, 05:34 PM
#96
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Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
Re: LO3 rebuild (HP estimates?)
Does anyone have a guestimate as to how much RPM the stock LO3 rods will handle ? I was planning on shifting between 6k&6500 but after some reading today I found out that 305 rods are NOT the same as 350 rods and are actually 30grams or so lighter than 350 rods ! ... I believe the rods are my weakest link here as I have arp wave lock rod bolts and arp main studs as well and the crank should easily handle 6500 seeing as I am having the bottom end spin balanced
09-11-2013, 11:45 PM
#97
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Car: 1991 firebird
Engine: TBI 305 (built)
Transmission: T5
Axle/Gears: 4.10
Re: LO3 rebuild (HP estimates?)
Well guys the time has come ! I'm going to pick up the engine from the machine shop Saturday morning as soon as I get off wrk ! And I am planning on having it assembled within a week and back in the car and running within 2 weeks from Saturday ! I'm taking my time and doing this right ! No shortcuts .... And I'm working night shift so ill only be messing with it a couple hours each day ... So anyway here's a couple pics of recent activity in the man cave (garage)....
Got most of the engine bay sprayed in primer today gonna finish that up tomorrow and Mabey go ahead and spray the top coat ... What y'all think satin or gloss black for the E-bay ? Or another color ?
Got most of the engine bay sprayed in primer today gonna finish that up tomorrow and Mabey go ahead and spray the top coat ... What y'all think satin or gloss black for the E-bay ? Or another color ?
09-15-2013, 09:26 PM
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Car: 1991 firebird
Engine: TBI 305 (built)
Transmission: T5
Axle/Gears: 4.10
Re: LO3 rebuild (HP estimates?)
went and picked up my engine from the machine shop Saturday so ill be starting the rebuild this week sometime ... Finished painting the engine bay today and got the garage all cleaned up an dust/dirt free them unloaded all the parts out of the trunk of my beater ... So here we go ! ... Can't wait to get this thing running again ! I've missed my toy haha ... Lets see what the little 305 is gonna do ! I also need to install my SFC's soon :-/ ... Or before track day anyway ...
Edit: oh yea .. Tomorrow I will just be finishing up all the little things that need to be done in the engine bay (wiring, painting crossmember etc.), rebuilding the old distributor , rebuilding the TBI unit with the new CFM tech injectors , gettin the oil pan ,bolts, etc. cleaned up and organized then prolly taking some measurements or the bores , journals, etc. if I have time that is .... Have to b at wrk @ 3 tomorrow :-/
Edit: oh yea .. Tomorrow I will just be finishing up all the little things that need to be done in the engine bay (wiring, painting crossmember etc.), rebuilding the old distributor , rebuilding the TBI unit with the new CFM tech injectors , gettin the oil pan ,bolts, etc. cleaned up and organized then prolly taking some measurements or the bores , journals, etc. if I have time that is .... Have to b at wrk @ 3 tomorrow :-/
Last edited by 1991sleeper; 09-15-2013 at 09:32 PM.