Hello there i am a fairly new member to this site and i have researched alot of info !
I recently pulled the engine on my 1994 Copper coloured vette !
Its a LT-1 - 350 -6 SPD.and i want to increase the horse power in it.
I would like to accomplish at least 450 hp and around the same in lb ft torque.
I have alot of ideas in mind but i thought i would ask people on this site for some ideas as well.
People that have gone through this up grade in power !
I am a Journeyman H D Mechanic up here in Alberta Canada,so i do my own work on this beauty of a car,its mint through out.
I hope there is someone out there that can help me in this adventure ,i would greatly appreciate any info,Thanks so much !!!!

 

How much do you have to spend (budget)?

Do you have to pass emissions inspection?

What kind of driveability are you expecting?

Willing to upgrade/change the rear gear/clutch & FW?

Do you have tuner in your area that can tune the 94 PCM?
Will

 

Hello,well to answer your questions,i do not have to pass emissions,i only drive on nice sunny days,never seen rain ,snow etc,willing to change gear train,and not sure of a tuner locally but i could send ecm away to get this done !
Also my budget is 5k---6k

 

Stroker time that will fit the bill, will be easy to drive and pull hard everywhere.

 

$5-$6,000 is a little tight on the budget for everything your going to need.

450hp (crankshaft) is not a problem. Thats about 360-380RWHP... You can utilize some budget minded parts at that HP level.

I can only estimate what machine work cost by what we charge and I'm not familiar with how close those prices will correlate to a good Canadian machine shop.

Machine work-
Clean -$100
Line Hone - $150
Deck - $150 ($75 per side)
Bore and hone w/plate - $200
Install cam brg/freeze plugs - $75
File Fit Rings - $100
Balance $200 (less if just check because you buy a pre-balanced kit)

Machine work total - $975.00

On the engine kit... You can make that power with a 355 but I'd prefer to do it with a 383. It'll make more TQ and be better to drive. It’s going to be more expensive thou.

I would buy this rotating assembly. Scat 9000 crank and I beam rods, SRP forged pistons, file fit 1/16 rings. Pre balanced neutral front and external rear so it'll work perfect with your LT1.

Scat PN 1-91060BIE

$1335.00

http://www.cnc-motorsports.com/rotat...p-pistons.html

Oil Pump. Melling PN M155

$46.00

http://www.summitracing.com/parts/mel-m155

Hardened Oil Pump drive shaft. PN IS55E

$9.25

http://www.summitracing.com/parts/mel-is-55e

Gaskets... You need to buy this stuff separately to get the best stuff for your application.

Victor .026 Head gaskets PN 5898

$36.00 ($18 each)

http://www.cnc-motorsports.com/victo...-per-pack.html

Fel Pro Conversion set PN CS9966.

$52.00

http://shop.advanceautoparts.com/buy...sket-sets.html

AFR Intake gaskets PN 6860.

$20

http://www.summitracing.com/parts/afr-6860

You'll need cyl heads... I'd recomend the AFR 195. With flat tops and a 3.75 stroke you'll need the 65cc chamber to put you at around 11.25 SCR

$1878 (there is a member here that is an AFR dealer and he can knock a little bit off that MSRP price for CF members... PM and I'll give you his info)

http://www.airflowresearch.com/produ...uifpr94vqbajg6
Head bolts –
ARP 3601 $80
http://www.summitracing.com/parts/ar...make/chevrolet

You need a cam. My cam grinder is Mike Jones. All his stuff is custom ground... so when you call you have to know what lobe series and what ICL and LSA you want or you can ask him for a recomendation... I'll give you my recomendation. The cam will have very docile manners, be easy to tune and have good power from 1500RPM and pull until 6000RPM. It will hit a very small lick at idle in a 383... just enough to let you know you got something under the hood.

HR68375/HR70375
272/280 advertised duration
220/227 @.050 duration
.375/.375 lobe (.600 w/1.6)
112 LSA (installed on 108 ICL)

$385
http://www.jonescams.com/2006catalog_001.htm

The rest of the valve train.

Rocker Arms - This is a trick because you need a good rocker that will work with the AFR 7/16 stud and still fit under the stock plastic rocker covers. My normal recommendation on rockers won't fit.... These TFS rockers are narrow and are good quality.

TFS rockers 1.6 ratio

$216

http://www.summitracing.com/parts/tf...make/chevrolet

You will need pushrods. You won't know the correct length until the motor is together and you plot the rocker geometry. Literally the last thing you buy for an engine.

TFS 5/16 .080 wall

$120

http://www.summitracing.com/search?k...pushrods&dds=1

You can reuse your LT1 roller lifters if they are in good shape to save $$$.

Also re-use your oil pan and windage tray. You will have shim the windage tray down to clear the new rods.

Timing chain set.... I left this until last because there are a few ways to go about this. With a 94 unless you spend more $$$ to upgrade to a pin drive opti you have to run the single row silent drive LT1 chain. Personally I'd spend the coin and buy a 96-97 cover, new pin drive optispark and either use the extreme duty chain set (OK) or run a double roller and convert to an elect water pump (best option)....

Your at $4200 in parts (minus some if you shop around on price) and $975 in labor before you tackle the timing chain deal....

The expensive but best way here is:
Used 95-97 timing cover $75-$100 on ebay

New Delco Opti SPark PN 19212300 $450

Mezier elect water pump $270

Cloyes Double roller timing chain PN 9-3145 $95

That’s $915 additional to upgrade the timing system to the best set up that exist for an LTX.

The above is what I recommend you do. I’ve been building/modifying/racing these LTX engines since they first came out and there is no way I will recommend using a 92-94 style timing set on a modified high performance LTX of any sort.

That said it’s your car and the cheap route is the Cloyes PN C3228 92-94 stock replacement timing chain…. You can reuse your stock WP, timing cover, opti spark….

Cloyes - PN C 3228 $97.00

All that’s left is Clutch and FW and headers/exhaust.
Spec Stage II Clutch – PN SC422Y
$450
http://www.lmperformance.com/5257/24.html
Spec steel SM Flywheel - PN SC05S
$270
http://www.lmperformance.com/5266/24.html

Headers… You can lots of $$$ here, but IMO the Headman Elite are a great deal for what you are doing.
$400
http://www.summitracing.com/parts/hed-68448

That’s about $6200 if you cheap out on the timing chain upgrade and about $7150 if upgrade to double roller and elect WP….

There is some $$$ to be saved by price shopping as I said. I could show you a cheaper rotating assembly but it won’t be the quality I prefer/recommend.

Building a good 355 is a little bit cheaper as you reuse your stock crank, spend $450 on pistons, $105 on rings, $260 on connecting rods, $32 rod brg and $40 main brg… total of $887

I hope that gives you something to think about. A lot of little stuff adds up to kill a 6K budget in short order and many people think ”hey it’s only $1300 for a 383 stroker kit and I’m all done”… it never works out like that and since I just pulled this stufff off the top of my head I'm positive I forgot a few nickle and dime parts.
Will

 

^^ Great post Will!!

 

Will is the man!

 

This post is pure gold for all LTX guy...

 

+1000 on "Will is the man". I'm just finishing up my build, most of which was recommended by him. If you follow his road map above, you should shoot well past your HP goal and have great driveablitly.

Do it.

 

Thanks you guys,especially Will,i greatly appreciate all the info.Do you work at CNC Motorsports ??

 

I do not work at CNC Motorsports... They are often just one of the best priced places to buy certain parts. They are one of many companies I personally buy from and have always done me right so I don't mind recomending them to others.

No problem on the info. I just want others to know what they are getting into.
Will

 

:QUOTE=rklessdriver;1582790383]I do not work at CNC Motorsports... They are often just one of the best priced places to buy certain parts. They are one of many companies I personally buy from and have always done me right so I don't mind recomending them to others.

No problem on the info. I just want others to know what they are getting into.
Will[/QUOTE]

Hello again,i have been on corvette forum a seen a 1994 convertable with a LS-3 engine installed in it and then i checked my local gm dealer and a LS-3 with computer and hardware goes for about 8k ,but the big question is,IS IT A PAIN IN THE you know what.
Does anyone out the know anything about this ?
Thanks again.

 

Nice job Will

Oh wait! did you forget the carb n manifold! hehehee

 

The last build I did was a budget LT1 build. To be honest it can be done right for far less than $6000. Forgive me ahead of time, I haven't slept in 24 hours, so I may skip something.

First: If the stock bottom end isn't hurt, why even tear it down? Stock bottom ends are pretty durable from the factory, but if you want to go through it for peace of mind, I guess it wouldn't hurt. Next, unless your factory parts are broken why change them out for Chinese steel? Factory cranks, rods, and pistons are plenty for a 450hp motor. Make sure everything is within spec and move on to having necessary block work done. Knowing I was within the limits for the factory components, I had the crank turned 10/10, resized the rods with ARP rod bolts, and re-ringed the factory Mahle pistons with Mahle rings. I got away with a cylinder hone and had the block decked a little for a true surface and compression bump. Now that you just saved a bunch of money there you can spend it where power is made.

Low end from a 383 just isn't enough of a reason to spend the extra money here, especially in the 3300lb car.

I agree with much of what rklessdrive said so hopefully he doesn't mind if I build on what he posted with a few changes. I agree with most of the smaller parts, gaskets, etc.

Here is the link to my budget build thread, it's on LTXtech: http://ltxtech.com/forums/showthread...ads-Comp-XE503

I'm behind on posting pictures, but the text is the important part.

Obviously if the pistons are out of spec or the block needs bored you'll be spending money on pistons, boring, balancing, file fit, etc. But the trick to saving money would be resusing the stock pistons and not having to balance, bore, or pistons. That would save you almost $900 right off the bat.

Quick math using rklessdrivers figures with my own:
Machining: $325
Rings: $60
Bearings: $75
Small parts: $161
Heads and Camshaft: $1200 [LE1 heads with matching custom camshaft]
Clutch parts and headers: $1120

= $2941 plus or minus small things we're missing.

Either way that's the majority of it and that'll get you to 450hp under $3000 unless you do the vented opti upgrade, they you'll be right at $4000.

I ran used heads with my build, reused factory pistons, used clutch and flywheel, etc to keep costs down. I'm around 450hp and I got 24-25mpg out of my last tank driving with some enthusiasm. This is currently in an Fbody.

Hope that helps a little, not trying to step on anyones toes, but I'm all about only buying what's necessary to reach the goal.

 

Bersaglieri -
I'm def not intending to bash you or step on toes either here - but I have to point out where I see false economy in your recomendation.

I agree with you that reusing the stock bottom end with heads and a cam can indeed make 450hp... Infact back in the 90's and early 2000's I did plenty of heads cam packages for LTX's... but it's 2013 and your talking about a 1994 - almost 20yr old stock bottom end, with ??? miles of use (and possible abuse) on it. Just my opinion but stock LTX rods and pistons are not up to 450HP for any engine I would consider attaching my name to. The GM crank I would have no problem reusing and you can see I gave him a second option of doing that with a 355....

The botom end is the castle for all HP production. IMO you can never spend too much money fortifying it. Stock used bores are not straight or round and they can not be honed round. It will not seal and at 450+hp rings have to seal. One of the things I spend the most time on our stock eliminator motors fooling with, is the bore... Ring seal is that important.

If you haven't seen the recent 93 ragtop's 383LTX build and dyno threads take a look... I built that new engine because his heads and cam mid 11 sec stock bottom end LT1 grenaded after a few years of use.... The engine he has now will live forever at the HP he's making (and it's a bunch).

There are very good reasons why I used the parts I did. I honestly hate imported cranks and rods but I can't tell a guy with a street car that he needs a Winberg crank and a set of Carrillo's... Import parts are all that fits in the price range. They are what they are - Certain ones are good enough for the job, cheap enough for the job and better than the stock stuff, so I recomend them for them job.

That $250 Comp cam you recomend is ground on an Austemper cast core... well known to be junk in any hi-performance useage. That $395 Jones cam is ground on a steel billet that has a pressed on melonized steel gear... BTW it cost $125 to upgrade to that Austemper cast core to a billet from Comp Cams. And then he's still stuck with a cam from that scum Scooter Bros instead of a real cam grinder. If you have never used Mike Jones on a cam, all I can tell you is that your missing out.

Lloyd has done some good port work and some not so good port work in the past... reguardless of which he might do in this instance, I can't risk my reputation on what kind of work he might turn out. AFR's casting is better and their CNC work while not ideal for everything is consistant, well known performance potential and they do take care of f ups promptly....

I have to tell you, I recently went thru this very secenario on a budget 450hp build recomendation - AI on a set of LT4 castings and that coupled with a home builder not 100% familiar with LT4 self aligning rockers and knowing to check retainer/lock clearance turned out as a real disaster for him. AI didn't send the heads back with guide plates so he thought he was good to go with SA rockers.

Your totally free to make whatever recomendation you want but put yourself in my place. I own a Race Engine Consulting Service in real life. Any thing I do on the internet for free, just to help someone out, when I have the time - still has my name on it. The internet is forever... You have to look at what a potential real customer of mine see's when he googles me... I'm not trying to float any BS here, I'm just telling you where I'm comming from.

What I would have done 10-15yrs ago just isn't what I'd do today. IMO there is too much potential for failure and a lack of capability of perform at the stated goals to recomend re-ringing a stock LT1 bottom end and pushing it towards the upper end of it's HP capability.

Of course I know what I've recomended will exceed his minimum HP goals by a bit but in the end thats good for him. He has a pretty good budget for building a good ENGINE ONLY... The way I see it, the extra stuff for the car he needs (clutch FW and headers) are what put him a little short.
Will

 

Extra 40 lbs min sometimes more..its not just at the bottom its everywhere that extra stroke works. It cost me less than $200 difference from doing the last 350 to the 383 night and day difference esp at WOT in the upper ranges. Prior 350 wouldnt have a prayer against this one and reused a lot of the same parts (intake heads etc). Always go bigger

Wont comment on pouring tons into old cyl heads.
Unless you have to/really $ limited, save more and get the good stuff.

 

sometimes to spend a few more bucks let you sleep and dream like a baby...

 

On the stock bottem end not being hurt part:......How do you know? Everything may look fine, but there may be a minor imperfection waiting to fail, especially on a high mileage engine.

My story: Last year I began improvements on my 1996 LT4. It had 82K miles on the clock and I decided to do the heads, intake, cam, headers...etc.....Everything seemed fine. The build went smoothly, the engine seemed tight. Compression was good...etc....Then, while idling the engine began to chirp very loudly. Then it shot off. Stacked 2 rod bearings. That led into the build I'm doing now, that I probably should have done in the first place.

If you have the budget to not cut corners, why would you want to? It only guarantees you'll be breaking out of your budget later with double work and rebuying parts.