Friggin need advice

[DarkoNova]

Ok so you guys may remember a while ago Car Craft carb'd an LQ4, put L92 heads on it and got 550 hp. So I was gonna do that. I just got the latest CC and they say that an LQ4 will die if taken to 6800 rpms too often (which is where the 550 hp was), so I'm pretty bummed now. And that's not even mentioning the fact that they actually had an LQ9 to begin with. :banghead:

So basically, I'm back where I was a year ago. I have an engine that burns insane amounts of oil, gets 13-15 mpg, and is in need of a rebuild. I have absolutely no clue what I want to do. I can stroke it out to a 383, I can get a big block, LS1, LQ4, etc.

So I turn to my fellow pro-touring addicts for advice. The only things I'm looking for are 500 hp (preferably at the wheels, but if I can get at least 500 hp at the crank, that's alright, too), 25 mpg MINIMUM, and hopefully not break the bank. That basically rules out the sbc and bbc because there's no way I can get such good mpg out of them. I've got around 10 grand to work with, but I'd like to get some disc brakes (I've got the ATS spindles, been sitting here for at least 4 months).

So basically, help me make a reliable 500+ hp engine that gets 25+ mpg. Is it possible?

EDIT: Oh yeah, this is going in a 69 Nova with a TKO-600 (.064 5th) with 3.42 rear gears.

Matt

[streetk14]

I say go with an aluminum block LSx motor, either an LS1 or LS2. The LS1s are definitely cheaper, especially for just a used motor. Find a low mileage motor from a salvage yard that comes with all the accessories and harness. Look for a 2001+ motor so it already has the LS6 intake. A mild cam, a good set of headers and nice set of heads should get you 500 hp at the flywheel without much trouble. You will then have a light-weight motor that will have no problem meeting your fuel economy goals.

If you want 500 hp at the wheels, that's a much bigger goal. I think that's going to take a stroker motor or some sort of forced induction. I guess you have to be honest with yourself about what you really want/need.

Getting back to the LSx motors, I feel that the aluminum block and fuel injection are two of the best reasons to do the conversion. Getting an iron block motor and putting a carb on it doesn't make sense to me. The aluminum block is more than fine unless you are planning to go crazy with the motor, and the driveability the fuel injection provides is amazing.

If I were doing the conversion, I'd try to get a LS1/T56 combo. The TKO 600 is a great trans, but the T56 is meant to be used with the LS1 and will help with your fuel economy goals. I'm not sure if you already have the TKO, or if it's in the car already, but you could probably sell it for a good chunk of $$$ to go towards the engine/trans combo. The reason I mention this is that I've had both a TKO and a T56, and the T56 is my favorite. The 0.64 OD on your 600 is really only good for a cruising gear (not performance use). The 5th gear on the T56 is a little more usable for performance, then you have 6th for highway cruising at low revs.

Just my 2 cents,
Andy

[Rybar]

My buddy just built an LQ4, why do you say they can't be taken to 6800?

You can get these cores cheap, add some ARP fasteners (especially the rod bolts) mill the stock heads to bump the compression up, or even add the L76/L92 intake with a nice healthy cam ~230+/230+ 112 and you should be well over 400 to the wheels, possibly 450+rwhp (which is over 500 at the crank)

Find a factory accesory drive from an F-body and you are set to a nice budget, EFI build.

[WS6]

If you want 25 mpg minimum and 500 rwhp you only have two options. Boost or nitrous. You're not going to get those numbers any other way. Now if you say you want 20 minimum and to stay NA, then you should be able to get 500 if not be very close. I would do like mentioned and look into the L92/L76 setup since you're a 6.0 you can easily do this.

CC is right, a stock 6.0 will not like 6800rpms. You can easily modify the engine to handle those rpms though.

Oh and don't waste going to a 383 when you can go 402 with just a crank change.

[DarkoNova]

The magazine said that the pistons won't take the abuse. I thought they would. :confused:

I found some articles online about the LS2. Apparently with a mild cam you can get around 490 hp (with a few other things, I think a TB), so now I really, really want an LS2.

Anyone have one they want to get rid of? I think that would be perfect for me. The article I was reading had a super docile cam on like a 114 or 116 LSA but it made like 494 hp. They claimed it was incredibly streetable. That might satisfy my taste for speed while getting 25 mpg. :)

Thoughts?

Matt

[MrQuick]

A good stock piston can take abuse if you are not detonating the hell out of them. There are usually other factors that will cause piston failure.

Not to offend anyone but I would take some magazine articles with a grain of salt. Same rag and very conflicting advise. I would find a good engine builder and put a build package together using quality parts. Don't worry about what stock parts can handle since you will go aftermarket anyways.

[Chad-1stGen]

500 rwhp and reliable 25+ mpg is not easily obtainable w/o turbo's. Also, while many motors might be capable of hitting 25+ on a long straight freeway drive, around town is where it's at. I think you are going to have to give in power or fuel economy with a 10k budget.

[MonzaRacer]

Ok for one WHICH engine are you talking about I am just dizzy trying to remember the lQ THIS, LS that and all the stupid designations.
Dont get me wrong I understand thats the new thing but I I do get confused with all the designations.
Now as for me take horse power numbers and forget'em.
Period.
If I had my choice i would go for a smooth,flat, fat torque curve and let the HP numbers fall where ever.
500 lb ft of torque and keep it smooth and strong, HP is nothing with out torque.
I had a guy who built a spec"300hp" 327 for his chevelle.
So he got his A$$ handed to him.
So we found some older heavy bouble humps with listed numbers and had them CNCed to match the numbers I gave them from a set of SR Torquers, we used 194/160s and made a solid 430 lb ft of torque, same cam/intake/carb and the car was litterally pullingthe front tires and skimming the lights, his rear set up simply consisted of an older adjustable upper control arm cross member from a Pontiac, a set of Southside machine lift bars and a set of ART CoolRide. (yes this car could run air if it had no electronic or driver adjustable controls.)
We set it up with manual fill lines and the car still got horrible 60 fts because the front tires may or may not catch the lights but it hooked nd went down the road and he drove it 300 miles to a race.
One part of the trip out we were playing with vettes in curvy roads and the car was awesome.
Heck get the dyno guy to pump up the numbebr s onthe dyno if you "have" to have "X" horsepower.
A good set of AFR heads, sawp in some good pistons and rods and a speced out cam and run it.

If you cna make it run hard and pull ahrd and match it to a good OD trans and some reasonable gears and tune the cruise side well enough you CAN get 500hp with reasonable mileage.
Everyone thinks 500hp is at cruise and its not its at peak efficiency and that is dependant on cam, heads and tuning. Oh and it meaets with torque at 5252 rpm so what ever.
Instead of dreaming call a head company and a cam company and make them seat the numbers for you.
Cam Mtion and Comp Cams can make you any cam you want with very good results, and as for the cam numbers it als odepends on heads.
Other than that simply rebuiolding a oil burner is going to bring you up 2-4 mpg and make a ton more power.
Lee Abel

[merriman44]

Darko, the ls2 block is only around 700ish. You can get new/slightly used forged rods of many lengths at ls1tech (their are 2 listings last week). Good forged pistons are around 600-700. Add a stroker crank for another 800 from eagle. Have a shop put it together/balanced/line-honed for aroun 500. Your looking at roughly 3.2k for a bullet proof bottom. Pick up pulleys over on tech for cheap and a full ls6 intake. Mild cam and good heads and you are way over your goal for way under the price.

But then you actually have to get it into the car and thats where it gets pricey. Just my take on it.

[DarkoNova]

Merriman, where are you finding these deals? I haven't seen any LS2 blocks for that cheap. The main reason I don't want to build the engine piece by piece is I don't know how hard it would be to get all the different sensors I'd need. If that's easy I may start looking at individual pieces so I can build a 402 stroker.

The main problem I have is patience. I've got all this money sitting in the bank and I hate seeing the Nova sitting in the driveway so I want the engine NOW. I've wanted to hit "buy it now" on one of those ebay listings for an LS2 and T56 so many times. :(

I know hp doesn't really matter (technically there's no such thing, it's just a number based off of torque), so let me rephrase. I want 25 mpg and the ability to run mid to low 11's, or better. I don't know how much power it would take to move 3500-3600 pounds that fast, so I just shot for 500.

So say I managed to get all the necessary parts for a 402. Assuming I had decent compression, some L92 heads and the L76 intake, it should easily make 500 hp, right? Or am I being optimistic? That sounds like a pretty reasonable goal to me. :)

Matt

[streetk14]

So, we are talking about 500 flywheel horsepower, right? 500 RWHP is a BIG difference (and not very likely with your budget), so I just wanted to make sure what your goal is. I'd go check out what kind of times F-body guys are running over at LS1tech.com. Those cars are similar in weight, so that should give you a better idea of how much power you may need.

Don't worry about making torque, the LSx engines always make good torque numbers, and strong HP to back it up. If you can afford it, my vote is for you to get a complete LS1 or LS2/T56 combo. You could go with an iron block 6.0 for less $$, but I'd rather have the aluminum block for a P-T car. Another thing to think about is that if you plan to change the heads and cam anyways, there isn't much difference between the LS1 and LS2 (except for 18 cubic inches). I haven't priced LS2s lately, but they used to be a lot more than the low-mileage LS1s out there.

You could build an engine from scratch, but I think all the little parts would add up in the end. A complete pull-out motor and trans is nice because you know almost everything is there. You could then worry about getting it running in the car, and make the performance modifications to the motor later.

Andy

[DCx]

i got ls7 lifters that are capable of 7000rpm for $99 bux new! just upgrade the valve train. i also went arp on the rod bolts $70 and if you can spare the cash i hear that harland sharp will rebuild the stock rocker arms needle bearings for $200-250. add some ported heads, hardened push rods, and the works and you are ready to go!

i forgot? did you go carbed? i found a place in texas that said they would port a ls1 victor jr for me, no price quote though. that should add some power along with some ported heads. man you can easily have a monster motor for 10gs!

im still debating the carb issue myself. and dont forget! i live like 3 miles from you!

[DarkoNova]

Yeah I could probably just get an LS1. I know they're basically the same as other LS motors but I don't know how easy it is to get power out of them. Would it be just as easy to get 500 hp out of an LS1? The main reason I want a 6.0 is to use the L92 heads. It'd be easier because I could just literally drop them on whereas I'd have to bore the cylinders to get them to work on the LS1.

Anyone have any combos for 500 hp LS1's?

DCx, I haven't forgotten. ;) You should stop by Target whenever (though I get off work at like 11 am so unless you're a morning person you'd probably miss me :p). And no, I decided not to go carb. Like I said, the only reason I was planning on carb'ing the motor was to speed up the transplant, but now I have another car for a daily driver, so I can take as long as I need to get this thing running.

Yeah 500 hp at the crank is fine. I figure that should be enough to get me into at least the low 12's, and I'll still have major traction issues anyway, so yeah, that should be enough for now. ;)

Matt

[merriman44]

Can't use the l92's with the smaller bore size of the ls1 though.

I got my deals from a fella in MI. If you want I'll get his number for you. The blocks are not expensive. As for the other stuff, patience will def. help. I'm in college so that all I have. My 69's body work is almost done then its on to the engine. All I need is a stroker crank and pistons (and yes all the little stuff, much of which I'll get from my beat up ls1 block). All the sensors from the ls1 will work for the ls2.

My advice if you wanna build it yourself (i recommend out of personal preference) is to find a junk ls1 and use all of its pulleys and sensors.

Your goal can be done for way less than 11000. I gaurantee it because I'm almost done with my shortblock and have less than 2500 in it.

[DCx]

sounds good. im glad you got your engine situation settled.

Darko, what target do you work at? redlands or sterling? only reason im awake this early is because of school. i normally work stupid hours ranging from 2pm to 1 am. if you look at a lot of my posts im usually up until 4am.

[streetk14]

[quote=DarkoNova]Yeah I could probably just get an LS1. I know they're basically the same as other LS motors but I don't know how easy it is to get power out of them. Would it be just as easy to get 500 hp out of an LS1? The main reason I want a 6.0 is to use the L92 heads. It'd be easier because I could just literally drop them on whereas I'd have to bore the cylinders to get them to work on the LS1.

Anyone have any combos for 500 hp LS1's?



You are really only giving up 18 or so cubic inches by going LS1, and there are a lot of people making very good power with them. I'd really suggest going over to LS1tech and checking out some F-body guys' dyno/track results.

This is a very popular LS1 combo from AFR: http://www.airflowresearch.com/ls1_dyno.php

Her's another similar motor that was built by a 3rd party (no AFR) : http://airflowresearch.com/articles/article042/A-P5.htm

A motor like these will drive very nicely and have no problem getting a nova into the 11's with decent traction. I think Tony Mamo's (AFR's head designer) C5 Vette was running very low 11's with this engine combo. I know his probably had some secret tweaks and a lot of dyno time, but it's amazing what a mild combo can do. You could substitute the AFRs for a set of Patriot LS6 heads and still make over 500 hp while saving a bunch of cash.

I'll try to track down some of the other LS1 dyno tests I've seen in the past.

Andy

[DCx]

this is an article from GM hight tech performance
http://www.gmhightechperformance.com/tech/0701gm_ls1_dyno_tech

what do you get when you take an LS1... add a Magic Stick 3 cam, and throw some ported PRC (texas speed) LS6 heads on it?

530hp on the engine dyno.

i have the same cam and heads. will see how it adds up.

[DarkoNova]

this is an article from GM hight tech performance
http://www.gmhightechperformance.com/tech/0701gm_ls1_dyno_tech

what do you get when you take an LS1... add a Magic Stick 3 cam, and throw some ported PRC (texas speed) LS6 heads on it?

530hp on the engine dyno.

i have the same cam and heads. will see how it adds up.

But they also used 101 octane. Still, amazing that they could get that much out of it. I don't understand why they said only diehards would drive the car with that cam because the powerband is 2300-6800. That seems like an awesome powerband to me. :yeah:

Still, heads are RETARDED expensive for LS1's. Another plus to the LS2: L92 heads are $1000 for BOTH.

*sigh* Once again, I don't know what I want to do. :(

Matt

[DCx]

the camaro is full of 110 right now! and i have 5 gallons just chillin. i got my heads for $800 plus shipping, the cam for $250, and the push rods for $85. cheap setup.

and yes, 2600-6500 is perfect for a 6 speed with 4.10 gears!