1991 Rs 5.0..
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1991 Rs 5.0.. Alright, guys. I don't know if any of you know much about the RS's, or the engine\specs, at all. It's the 5.0 (Chevy 304) engine, and it's estimated at roughly 240rwhp, probably about 230 at the wheels. I just got this car, and I plan on using it as my drag\street car, that I can still take to shows. So, my question is this: What is the designation for the block? What are some bolt ons I can use to go faster? (CAI, Cams, Stroked, things like that?) I'm coming over from driving a Mustang. I had a Camaro Z28 before that I sold for my current 5.0.. And now I'm missing the Chevrolet's reliability. So, what do you guys think?
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Wrong forum, man. Not tryin to be a dick, just saying you might get a lil more attention in the SBC/BBC section. Now to answer your question.......
To tell you the truth, if you are after building the car up you don't want to keep the 305. It was designed and built for no reason other than to meet smog regulations. They do not respond well AT ALL to mods. There is a good reason for it being known as "the boat anchor", that reason being that it is quite possibly the worst chevy v8 ever built. If you really want a 3rd gen it would be a lot smarter to do an engine swap than to bother with the 305. a Gen 1 350 or an LT1 are both direct swaps that you can do without destroying your bank account. You could go LSx as well, but that will involve a few more changes since it is not the same bolt pattern, etc., whereas everything from the very first small block chevys on through LT1s uses the same bolt pattern.
EDIT: by the way, the 91 TPIs make 230hp at the crank, which translates to probably about 195 hp or so give or take through a manual if you figure 15% drive train loss.
To tell you the truth, if you are after building the car up you don't want to keep the 305. It was designed and built for no reason other than to meet smog regulations. They do not respond well AT ALL to mods. There is a good reason for it being known as "the boat anchor", that reason being that it is quite possibly the worst chevy v8 ever built. If you really want a 3rd gen it would be a lot smarter to do an engine swap than to bother with the 305. a Gen 1 350 or an LT1 are both direct swaps that you can do without destroying your bank account. You could go LSx as well, but that will involve a few more changes since it is not the same bolt pattern, etc., whereas everything from the very first small block chevys on through LT1s uses the same bolt pattern.
EDIT: by the way, the 91 TPIs make 230hp at the crank, which translates to probably about 195 hp or so give or take through a manual if you figure 15% drive train loss.
Last edited by nighthawk15; Jan 18, 2008 at 03:39 AM.
alot less than that at the wheels....you best bet would be to ditch the 5 liter, and build a motor. 383, 396...to keep it on the somewhat budget side, throw a victor jr w/ a carb.
Since you have an RS you have the L03 5.0 TBI which was not rated at 240hp. It was rated at 170hp. The 305 TPI which is the base Z28 engine was rated at 190hp. And finally the L98 350 TPI was rated at 240hp.
Most ditch the 305 but there was a guy on thirdgen.org (a place you should become very familiar with) running high 9s in his stalled auto 305 TPI with a single turbo. That is definately not the norm for those engines however but with the right work it can be done. I would yank the 305 and toss it in an s10 or something for a dd if you don't have one, then get you a 350 block and build it. With the advancements in aftermarket EFI, there is no need to go with an LT1 anymore, and the LSx swap is incredibly expensive. A built 355 with forged parts and the right top end will run great so long as you don't fall into the hype of stock and cheaper aftermarket parts. Get some good heads like Trick Flows or Darts, have them ported and flowed locally then contact a cam grinder (NOT Comp) and have them design a cam around your heads. Then stick a converted LT1 intake on it, a set of long tube headers and full exhaust and have fun. I bet you could make over 400rwhp very easily and stay NA if you wanted to.
Most ditch the 305 but there was a guy on thirdgen.org (a place you should become very familiar with) running high 9s in his stalled auto 305 TPI with a single turbo. That is definately not the norm for those engines however but with the right work it can be done. I would yank the 305 and toss it in an s10 or something for a dd if you don't have one, then get you a 350 block and build it. With the advancements in aftermarket EFI, there is no need to go with an LT1 anymore, and the LSx swap is incredibly expensive. A built 355 with forged parts and the right top end will run great so long as you don't fall into the hype of stock and cheaper aftermarket parts. Get some good heads like Trick Flows or Darts, have them ported and flowed locally then contact a cam grinder (NOT Comp) and have them design a cam around your heads. Then stick a converted LT1 intake on it, a set of long tube headers and full exhaust and have fun. I bet you could make over 400rwhp very easily and stay NA if you wanted to.
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Ah. Thank you for the responses. Suprisingly, this is what I wanted to hear. I'm going to be using the RS as, essentially, a toy. I've got to rebuild or swap an engine for my GM Certicification, and this sounds like the perfect way to do it. 
So here's my next question.. Swapping a full LS1 in. Is that possible? And, sorry for posting to the wrong section of the forums, I'll post this over at thirdgen also.
So here's my next question.. Swapping a full LS1 in. Is that possible? And, sorry for posting to the wrong section of the forums, I'll post this over at thirdgen also. 
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The L03 is also a roller motor, which is a plus if you plan to further it. Also they actually respond well to LT1 cams with a tune and some other upgrades like a 454 TBI (assuming it has the high flow injectors and not the really low flow ones in a high pressure system).
Also, the above ratings are right for power. Your BEST idea for it would be to make it a 305/350 TPI motor and not leave it throttle body as it is. For this, the best I can help you is I have a TPI base plate and runners I could sell you. You'd still need the TPI Upper Plenum though and the fuel rail + injectors. I might have 1 rail left but no injectors in it. Also it's a 88 fuel rail, and you'd have to remove the 9th injectors (for cold starts), but that should just be a simple removal of the plumbing and plug up the hole with the right sized thread plug. Aside from that you'd also need the wiring harness (Painless Wiring sells a kit for $300 which has everything) and a computer for it. Your stock computer won't work for it, but the TBI distributor and the rest of the ignition parts will still work.
Yes you can install an LS1, but just like installing a TPI setup, you'll need all the wiring, computer, etc etc. More expensive and more work than installing a TPI setup. The LT1 is still the same like the LS1, would be more expensive than TPI, but maybe less than LS1.
Also, the above ratings are right for power. Your BEST idea for it would be to make it a 305/350 TPI motor and not leave it throttle body as it is. For this, the best I can help you is I have a TPI base plate and runners I could sell you. You'd still need the TPI Upper Plenum though and the fuel rail + injectors. I might have 1 rail left but no injectors in it. Also it's a 88 fuel rail, and you'd have to remove the 9th injectors (for cold starts), but that should just be a simple removal of the plumbing and plug up the hole with the right sized thread plug. Aside from that you'd also need the wiring harness (Painless Wiring sells a kit for $300 which has everything) and a computer for it. Your stock computer won't work for it, but the TBI distributor and the rest of the ignition parts will still work.
Yes you can install an LS1, but just like installing a TPI setup, you'll need all the wiring, computer, etc etc. More expensive and more work than installing a TPI setup. The LT1 is still the same like the LS1, would be more expensive than TPI, but maybe less than LS1.
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Hmm.. Sounds good, about. I'll be doing an LS1 swap regardless, just not soon. I'm still scavenging around for a block. 
Anyways.. So swapping in an LT1 350 cams, throttle body, and plenum will show a boost in performance, but for that I'll also need the wiring harness and a new comp, correct? I've still got roughly 1200$ to play with here, to make this thing go zoom. Any suggestions on a budget like that?
Anyways.. So swapping in an LT1 350 cams, throttle body, and plenum will show a boost in performance, but for that I'll also need the wiring harness and a new comp, correct? I've still got roughly 1200$ to play with here, to make this thing go zoom. Any suggestions on a budget like that? LS1 Tech Stories
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Hmm.. Sounds good, about. I'll be doing an LS1 swap regardless, just not soon. I'm still scavenging around for a block. Anyways.. So swapping in an LT1 350 cams, throttle body, and plenum will show a boost in performance, but for that I'll also need the wiring harness and a new comp, correct? I've still got roughly 1200$ to play with here, to make this thing go zoom. Any suggestions on a budget like that?
Anyways.. So swapping in an LT1 350 cams, throttle body, and plenum will show a boost in performance, but for that I'll also need the wiring harness and a new comp, correct? I've still got roughly 1200$ to play with here, to make this thing go zoom. Any suggestions on a budget like that?Even stock it will be leaps and bounds ahead of that motor modded with the same amount of cash.
Another piece of advice, is to NOT buy an LS1 block. I did that thinking I could piece it together as I found deals on parts and came across extra money. But, what I didn't know before hand was how many covers and small pieces were used on the engine that hardly ever show up used. I ended up selling it for a huge loss.
I still stick by my original suggestion. Build a SBC for it with an aftermarket ecu. Check into the megasquirt setup (search google for info). Its a GREAT setup and can be mated to a sbc VERY easily and is on par with the newest LSx based ECUs in terms of what it can control. SBC is the way to go for that car as you can build something truely nasty without taking a huge hit on the budget.
As for your current budget, I wouldn't do ANY mods to the 305. Drive it until you save some money and then build the engine on the side. A cam swap is hard enough in those cars, no sense in doing one and then a little while later pulling the engine for a new one. Plus it might keep the frustration level down as well which is always a good thing.
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People typically refer to the Gen 1 small blocks (anything before the LT1) as SBCs. By the way, pardon my brain fart in my post from last night. For some reason I was thinking of the LB9 Z28s, which did have 230hp and came with the L98 cam. The above stated is correct for your car, the L03 only has 170, which would mean ~140 or so at the wheels. An LS1 swap is entirely possible, it just requires some extra stuff like a different k-member among other things and just all said and done costs a lot more, where an SBC or LT1 can use the existing motor mounts and everything (except of course the computer). For a budget build I think a carbed SBC would be right up your alley. If you want an injected engine and still want to keep it somewhat on the cheap then go LT1. The TPI injection system, just like a 305, is not good for a performance application. Hence why you see so many guys with carb swaps on TPI engines.
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Ebay might be an option. I've seen some pretty darn cheap LT1s on there before. Craigs List and for sale sections on forums like this one are good places to check as well. What it really comes down to is what do you want? An old fashioned carbed SBC, or rather a more modern injected version (LT1) with a computer? Both could be good choices for your application.
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Night, the TPI motors do/can make power, just they don't like higher RPMs. They are lovely torque monsters though! Great for trucks IMO.
The LT1 should be fairly easily found in almost any state I'd think. The easiest swap for you, assuming you have the automatic transmission, would be from a 92-93 LT1. They aren't as easy to tune as far as the computer goes, but it'll save you money since the transmission will work from your 305. In 94 they changed to an electric version of that transmission, which the computer controls. So if you get a 94-97 LT1, make sure you get a 4L60E from something V8 to go with it. Also only 94-97 will work with a 94-97 motor. 94-95 and 96-97 use slightly different wiring harnesses, so make sure you get the correct year harness for what year motor you get. If you DO get an LT1, you can always ask here and we'll help.
Also, for about the same price as a stock LT1 with all the stuff needed, you can probably do like Night said and just have that motor sent to a good shop and turned into a 350, 383, or whatever you want, and then carb it. You can still use that transmission, but if you DO, make sure you get it built nicely to handle the motor. Likewise, you'll want to look after your rear end. It'll hold up for awhile under 450hp, but don't expect it to last forever, especially since it's use to begin with.
The LT1 should be fairly easily found in almost any state I'd think. The easiest swap for you, assuming you have the automatic transmission, would be from a 92-93 LT1. They aren't as easy to tune as far as the computer goes, but it'll save you money since the transmission will work from your 305. In 94 they changed to an electric version of that transmission, which the computer controls. So if you get a 94-97 LT1, make sure you get a 4L60E from something V8 to go with it. Also only 94-97 will work with a 94-97 motor. 94-95 and 96-97 use slightly different wiring harnesses, so make sure you get the correct year harness for what year motor you get. If you DO get an LT1, you can always ask here and we'll help.
Also, for about the same price as a stock LT1 with all the stuff needed, you can probably do like Night said and just have that motor sent to a good shop and turned into a 350, 383, or whatever you want, and then carb it. You can still use that transmission, but if you DO, make sure you get it built nicely to handle the motor. Likewise, you'll want to look after your rear end. It'll hold up for awhile under 450hp, but don't expect it to last forever, especially since it's use to begin with.
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Yes, it is an automatic, and I have found quite a few LT1 engines on EBAY. One group sells only LXX engines, so.. Some of them come with transmissions + all belt driven everything and wiring harness \ ECU. So far, all I'm doing is exhaust and CAI. It's got a good 107k miles on it, too, so I'm going to drive it around to about 130k, by then I should be good to get the engine swap going. I've got a 2006 Mustang GT S/C'd as my daily, so at least I wont be without some Muscle..
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Oh yeah man, they definitely have nice power down low, but partially due to the runner design on the intake they peter out after like 4500RPM (correct me if I'm wrong). I mean that's ok for a truck like you said but IMO that's not something I would want in my car. I do not have personal experience but if you are looking to build serious power I have always heard that the TPI intake was a serious limiting factor and should be replaced with a carb. Again correct me if I'm wrong, you seem to be more experienced with TPI than myself.