Clayton91

Hello Im new here
Before I start I would like to thank this site with all the information Iv found on here in the past. I hope to learn and share my many new odd end builds that are to come. ALSO I would like to say this here and now....I KNOW a 350 or 383 would be better. It just would be in terms of power. I know. Trust me I know, Iv built a nice 355 in highschool and a high compression 350 last year. I know....

So my birthday is this week and I got a free pass to what ever I could find at the pick-a-parts in Houston from my father. After running around I came across a 96 caprice that was stipped apart from the engine, after taking at look at the back of the block I found out why. It was a 4.3L V8(l99 aka "baby lt1"). For those that have never neard of the engine, it has the same intake/48tb as the LT1. Reverse flow cooling and iron heads that are nearly the same as the B-body LT1 but with smaller cambers and intake valves to better match the bore size, which is 3.736in. The cam is the same as the B-body LT1/Vortec trucks. The rods are shorter and the crank is 3in. There was NO LT1's, TPI 350s, LSx to pick from. I liked the look of the engine and given my goals I figured it will do for this adventure.

The plan is to hit 330-350whp-350-380wtq with 10psi through a automatic with E85. By my math and in my head I would need to hit about 220-230whp N/A to have a chance to reach the goal under boost. Which I think is very possible. A 3.48 crank and 5.7 rod will drop right into the block, making it a 305. Stock the L99 makes 200hp-260tq while a vortec 305 makes what? 230hp-280tq??? So I would think the cid bump along with the better intake would put the engine a hair above stock 305 specs.

Questions...
1-Pistons!!! Im at a toss up of either KB hypers for $350 or forged, which run over $600 I don't see the point of going all out with forged slugs on a 305 and the power levels I seeking. Iv read that KB is a good brand and people have used them with mild boost or small nitrous hits. Opinions?
2-Turbo size. Im thinking of snatching up a used HX35 on ebay, their cheap and I found at least one guy who used one on a stock lg4 that made 300ish whp at 10psi. The engine died shortly after due to the stock pistons couldn't handle it. The HX35 seems to match to the size of the engine and psi level Im looking for, any input?
3-For the cam I was thinking of just using 1.6 rockers to give me a lift of .442/.457 with a LSA of 111, this would save a few bucks and keep my rpms low given I don't want to turn over 5800rpm given cast internals/turbo size. Good idea? Stupid idea? Should of got a 350 I know.

I will be giving E85 a try aswell, a station not to far from me has it. I know the oct rating is higher then that of 93(highest I know of in my area and I ran my HC 350 on it) but I heard it has a some what cooling effect under combustion. Given my engine is around 10-1cr with iron heads, the E85 combined with the reverse engine cooling system I would think it would better my chances of things not going BOOM at WOT under full boost.
I have started the clean up the engine and everything looks in very good shape. I'll be posting photos along the way and once dyno day comes I'll post a video I would like to find a good f-body to put it into but my project at the moment is a 85 Suburban that was my DD but has been promoted to project status now. Thus another reason why I don't want to rev the engine to high, incase I slap it into the truck which weighs about 5200 pounds.
And yes I know a 350 would of been better in Everyway.

Orr89RocZ

iTrader: (20)

E85 is good idea. Keep budget and use kb pistons. Fine with spot on tune and e85 will keep it safe.
Hx35 may work ok. Hx40 maybe good as well. I forget the exact specs but i believe the 35 is a 60-ish mm?

Throw in a 350 LT1 cam

Clayton91

Thank you sir for a non "350" opinion lol. The hx35 is 57/78mm compressor and 60mm turbine exducer. But I peeked at a dodge site that says you came upgrade to a 60mm compressor. The hx40 came with a 60mm stock.
Didn't think about getting a cheap fbody cam vs the 1.6 rockers in the hp-$ area. Im sure the cam on ebay will be cheaper then the rockers. And I was leaning heavy on the KBs as I just don't see a reason to go forged on a 305, though I looked online all weekend and couldn't find anyone els that has done this with a LTx. For good reason Im sure(lt1)

Orr89RocZ

iTrader: (20)

Hmm that is a smaller turbo for a single. But small cubes helps. Just like to see a little larger turbine housing as 8 cyl feeding that will spool rather quickly but have backpressure issues early in rpm range.

Gt45 wouldnt be bad. Much bigger turbine and a good 69mm comp but that is slightly overkill. On3 budget T70 is a good choice here imo. Its what i am gonna try on a remote turbo setup 305

Clayton91

Im in no way ready for a twin set up, at least for this build. I'll look into what you have listed later on tonight and get some prices on them, I know I have to change my fuel lines to use e85 but is there a special type of injector I have to use? I know carbs have to have things either done to them or be built to run e85.

Fast355

iTrader: (2)

^^^

x2 on the LT1 cam

The Vortec truck cam is JUNK!! I could not stand that POS in my Express and never gave my brothers Suburban a chance to live with it either.

I have built a stroked L99 before and it went into a B-car. Used a vortec 305 crank and rods. Then used the L99s LONGER rods and 3" stroke crank in a 1-piece rear main seal 350 vortec block to make another 305 with a 4.030" bore.

The stock pistons will live to a very respectable power level, IF you prevent detonation from ever happening with aggressive timing retard under boost and keep the tune rich enough to help keep them cool.

Orr89RocZ

iTrader: (20)

And e85 will further keep cylinders cool due to alcohol content

Clayton91

How did the 305 destroker work? Im wanting to do more or less that same thing for a engine to put into my fathers monte carlo(1981) that hes wanting to make into a show car. He isn't looking for a 500hp monster but I think 300-350 crank n/a would be more then enough for him.(I have a 1pc rear seal block 350 in my burb that ill be swaping for this LTx till I can find a fbody)
The e85's cooling effect is the main reason I wanted to use it, as for the higher oct rating really making a difference Im not sure on. Iv read some say it put out more for them vs someone els. Im looking at a lt1 fbody cam for $80 on ebay so that's works for me lol. The t70s are within reason to me aswell. I'll be making a order next Monday(pay day) for the cam.
Arent the stock L99 pistons hypers like LT1s? The block will be fully torn down after I get off work Tuesday and I'll be able to get a good look at them.

Jay_rich

iTrader: (4)

Cool to see something different. Plus side is people basically give LT1 stuff away. My old 383 LT1 single turbo setup made 584whp on 7-8psi on a terrible 10.0:1afr tune. Would be interesting to see this thing. Any plans on tossing on a set of LT1 aluminum heads? Keep the weight down a bit.

Jay

Fast355

iTrader: (2)

It went into an early 80s 2 door Malibu with a T-56 and 4.10s behind it. Was a little screamer but did not have much to offer in low-end torque.

The 305 L99 actually ran pretty well in the heavy caprice it was in. Replaced a blown up 350 (hole through the side of the block). Keep in mind this was nearly 10 years ago and good LT1s were not nearly as common or cheap.

I actually have a 1998 K1500 Suburban I am thinking of putting a Vortec 4.3 with a CPI cam, Marine intake, and small single turbo at about 8-10 psi and hanging a 4L80E behind it. I am thinking plenty of power to pull a good size trailer and 20+ mpg unloaded.

I have had hyper pistons live over 500 hp and 6,500 rpm with nitrous. Biggest thing is keep the ring gap a little on the wide side, keep it cool with a rich tune, and be conservative with the timing. You can reliably make some good power number. Also need some good valve springs, especially on the intake side. Rememeber if you have a 1.94" valve you have 2.96" of area and at only 10 psi of boost you just lost nearly 30 lbs of valve spring pressure.

1991sleeper

iTrader: (-3)

Interesting ... I built a pretty hot 305 sbc not too long ago and my .030 over hyper flattops from speed pro were only 160$ a set at summit

Clayton91

I seen speed pros on summit but Iv heard they was trash. Always heard good things about KBs for what they are. The alumy lt1 heads I could get for about $300 on cragslist but I had a porting shop down in Houston tell me they couldn't go on a l99. Which I didn't understand at all given the l99 heads are almost the same as the lt1 irons(which flow more the alumy).
Im looking into trading off the burb for a 80s gen fbody or the alike before I get the turbo parts together so I can figure out how to jam it all in there. Talking to a guy right now about doing a swap for his 89 camaro

Orr89RocZ

iTrader: (20)

While its true you typically need abit more spring for boost, the math doesnt exactly equate to psi over valve area for additional spring load. Theres still a differential pressure across the port and chamber thats similar to na type builds, esp if you have a good turbo system and actually some back pressure in not so efficient hotsides, so spring rate doesnt need to be increased dramatically. Motor still works similar way to na just working in denser environment.

Definately open up rings. Too wide wont hurt power much if got good bore surface and ring seal procedure on break in. Too narrow will kill a motor.

1991sleeper

iTrader: (-3)

We'll I hope they ain't garbage cause that's what's in my motor :-/ ... And I'm gettin ready to spray her 150 wet shot ... Gonna start out at 75 though n work my way up ... Hope they hold :-I

Clayton91

I seen the speed pros you had a did some searching few days ago and I couldn't get any positive remarks for the post 10's, they are made over seas from what I was reading. Im sure they would work fine n/a or a small shot, I just didn't want to risk it boosting ya know?
Noted on the ring gap
And as of right now I'll be picking up the 89 Camaro after I get off work. Guy says he got it for a project but lost interest, also says its a 350 with a carb...to the best of my know-how they only had the l98 in the thirdgens for 350cid and only carb'd engines was 305s. Soooo this is what Im betting made him lose interest in it lol.

Clayton91

Got the oil pan off and peeked inside, also gave the heads a bath. I noticed that in the intake port there are little pot-holes in all of them. Is this normal? At first I only seen one and thought I had a bad casting, went port by port and they all have it in the same spot and same depth. I'll post some photos of that after I get some time tomorrow evening if no one knows what Im talking about...

Clayton91

Snapshot_2014092Snapshot_20140925_2.JPG5_1.JPGSnapshot_20140925_3.JPG
Just got my 89 home last night, traded the burb for it

Clayton91

After looking around the engine bay and under the car Iv come to see the biggest difference between this and my c10s...hardly anyroom in there lol. Next series of questions are.....

This there any disadvantage/advantage to a rear mounted turbo? Or would I be better off having it in the engine bay? And also when it comes down to getting the engine back together should I wait till I have the whole FI system ready, put the engine back in the car and wire it all up/install the system then tow it to the dyno Im using to tune it. OR get the engine together, get it in the car and wired up/dyno it N/A. Then install the system on a later date once I get everything els finished with the car(transmission and the alike)

Clayton91

Well the block is fully apart at last. had some free time this morning and cleaned up the rockers. Good call on getting a different cam, the stock stick doesn't look to good. Looking at a lt1 cam from a Camaro for $80 on ebay and will be placing the order Monday evening.

Clayton91

Update. Just ordered my LT1 cam today and it should be here by friday

1991sleeper

iTrader: (-3)

Need some roller rockers and a LT4 cam

Clayton91

I think the lt1 will do for this build, the hot cam was a tad out of my price rang for this)I paid $80 for the lt1). Really want to get this engine together before new years so I can get to work on the trans and rear end, just itching to drive it.

83 Crossfire TA

iTrader: (2)

Cool build... I like 305's

I don't see why the aluminum LT1 heads wouldn't work on it, I'm setting up a set for a 305 SBC and everything looks like it's going to fit fine (well with changes done to make them work on an SBC.

An HX35 will be on the small side for it, you can use it to get it running and you can run the rather low HP numbers you're expecting (I know back in the day there was a 302 mustang build with one that got into the 4xxHP range, but it really was smallish for the engine making that power), but the whole thing would be happier with an HX40 or bigger.

I'd also be very tempted to try to find something a little bigger than any of the stock cams, it will be much more fun that way

Orr89RocZ

iTrader: (20)

I am goin zz4 in my 305 rear mount over this winter

nytmare

iTrader: (1)

I'm just throwing this out there for something to think about. I built a 88 Fiero with a 3.4 v6 and rear mounted turbo, had to use a pump to pump the oil back to the pan. If for some reason the pump fails oil gets by the seals on the turbo and makes for a large smoke screen lol. If I was to do it again I would mount it under hood and use gravity to return oil.

Orr89RocZ

iTrader: (20)

Oh i am fully aware lol run a oil pump on my black car. 2 years no issues. Knovk on wood. Gonna run same pump on the 305 car i got.
The reasons? Simple.
Dont have to touch motor. Leaves all emissions, accessories and ac in place. No excess heat in bay like my black car. No real fab required. And main reason, its different. Stealthy too, people wont see it and think its stock

Clayton91

Iv thought of a rear mount but iv read a TON of mixed opinions of it, mostly due to less heat causing the turbo not to spool right...or something like that In my mind i thought it had more due to velocity of the gasses exiting rather then how hot it was that spooled it. But then again I honestly am new to turbo tech, trying to fixer how to read the charts and such.
I would like to put on out back given I could just run a single exhaust to the rear and have room to run the air back up that snake channel, not much room in the engine bay. least to me(mostly worked on c10s)
Id have to agree on the hx35 being a tad small after talking to some people about it. Once I the engine its self together and all the wiring, ill start hunting for the turbo more seriously. By that point I should know forsure what I want lol.

Clayton91

Update-LT1 cam is in at last, ups was two days late
I cleaned up the intake and have started painting it, got two coats of gloss black on and be hitting it with one more in the morning. Fallowed by a clear coat or two after work.

Talked to a coworker about where he gets his head work done and I'll be having my l99's flow benched at some point, interested on what the numbers will be. Iv tracked down both a HX40W and a GT45 that I can get at any point that's within budget, Im thinking on getting the GT over the HX now. Over the last week there has been a good amount of trash talk between the men in the family on who's car will be faster once I get mine running aganst my brothers 95 mustang gt(5.0 auto with stock stall, has gt40 intake-coldair, shorties and true duels, "bigger" injectors) but the car has sat in my parents yard a good 4-5 years now, trans was slipping in OD at that time and still has the same gas in it from being parked

I'll be getting a new camera come pay day so I can take some good photos for a change, sorry about the webcam shots lol.

1991sleeper

iTrader: (-3)

I really think ur gonna wish u woulda went ahead b bought a new cam for it .. Like 212-220 @ .050 intake on 114 lsa for boost

Clayton91

:/ honestly after sitting out in the shed taking off a engine mount that was left on it I started thinking about the cam. Not like I cant swap out later on or flip the lt1 stick, still a good ways to go till its together and running. Need to sell off all my GEN 1 stuff and may get the extra cash to up the cam a bit. If not I'll have to settle as is for now.
JC but what does your l03 put down and run in the quarter?

1991sleeper

iTrader: (-3)

It's not really a lo3 anymore lol ... But I believe it's good for 8.00 1/8th on sticky tires trapped at 88 mph on street tires with 2.2 60' :-/

Clayton91

That's what in the 1/4th? a mid 12's? Haveyou sprayed the speed pros yet

Orr89RocZ

iTrader: (20)

Yeah 88 1/8 is good for mid 12's. conversion is 1.56-1.57 times 1/8 et.

1991sleeper

iTrader: (-3)

Nope no spray ... And I figured with some sticky tires to get my 60' downs to 1.8-1.9 I may get 90+ out of it after headers and diff exhaust ... Just haven't done it cause don't have $ for a new trans still has bone stock clutch and T-5 in it with 200k+ on trans and 100k on clutch ... Noticed some slight clutch slip in datalogs around 6000rpm 2nd &!3rd gear when running those numBers
Eventually wanna go T56

Needless to say several 350's @ track have stood over my engine bay scratching their heads in disbelief "that ain't no 305" lol

Clayton91

Very nice, I didn't think a T5 would go that long. Ever dyno it? Mid 12's is where Id like to get with this engine.
Iv never been to a 1/8 mile track, always go to a 1/4th. May check out the one that's in Houston, its a lot closer the where I go to most of the time.

1991sleeper

iTrader: (-3)

Nah tune still ain't nailed down as I've went through recent changes ( flow master gone / race bullet dumped at axle installed and injector swap) ... Closest dyno to me is prolly 2 hrs closest track 15 min ... Wish I had a 1/4 mile track closeby also ..... Also wish i da went with 112 lsa instead 114 and found a cheap 400 crank lol 334 :-o ...

I'll have this motor @ 400 N/A horsepower at crank before it's all said n done with 310cu.in (goal)

Clayton91

400hp n/a is nice goal, when I first got this ltx I thought of getting the 3.75 crank to make a 330cid(ish) but already have a good 3.48 on me. Closest dyno shop is about 35 miles from me and the 1/8 mile track is about 70 miles, 1/4 mile is 95 miles
Never been on a dyno, this engine is a LOT of firsts for me. Really trying to just get a good running small block together that I can swap over to a more serious LTx later on when I have a bigger budget.

1991sleeper

iTrader: (-3)

My advice is good rod bolts good rings n bearings n good oil pump and take ur time

Clayton91

Yes sir. Ill be ordering all new cam/rod bearing from summit with APR bolts on everything. Im still looking around on valve springs and lifters for it.

1991sleeper

iTrader: (-3)

If ur gonna stay with the LT1 cam atleast go with springs one step up from what is recommended ... IMO I'd go with some good beehive springs ... They cut down on valvetrain weight and are more stable at high RPM ... Any $ spent lightening valvetrain parts is $ well spent ... Makes for a snappy quick revving engine ... I plan to add some beehives , rev kit, little bigger cam , small single plane intake and 1.75" (has 1.5" primary shorties now ) primary long tubes one day ... Nowhere near in that order lol...

That will prolly b the full extent of this motor besides Mabey a 100 shot wet kit just incase it's needed :-p

I think my N/A 400fwhp goal would b far surpassed with all of the above..Mabey :-o

Wish I woulda had the $ for total seal gapless rings when I built it but I didn't so just went with KING bearings and some good moly rings ... I also blueprinted the whole engine myself with some PDF spreadsheets I downloaded and my micrometer / snap gauge set

Clayton91

Iv been looking into beehives, never tried them before and figured this would be a good time to give em a try. Same goes with the gapless rings, came along them last week while looking around summit. Talked to streetlethal and got a link for head gaskets...hard to find anything past stockers for this engine :/

Jay_rich

iTrader: (4)

I ran pac 1218's in my old 383 LT1. Very reasonably priced springs. It had COMP 918's in it before and had valve float issues (aggressive cam) Swapped to what should be he same sping PAC 1218 and the car picked up 60whp.

Looks forward to the build. No-one gives the LT1 love. i loved when i had a turbo Lt1 since everyone was LS already. But when I cracked the crank etc it made more sense to go LS. Probably shoulda played it out since I had a solid block, splayed mains, o-ringed deck etc. Same block is in my buddies 8 second 6 speed LT1 Camaro.

Jayu

Clayton91

Dang 60whp? That is some major float lol. Iv always loved the look of TPI and the LTx's, the LS may be easyer to get power out of but I just don't like the look of it :/ Im leaning more towards a GT45 on this and I see your using one of the 5.3, think it would run alright on the 305?

Jay_rich

iTrader: (4)

Cant tell you from personal experience as I am currently building mine (tread is a few down, project deja vu). It would probably be a bit laggy on a 305 down low. Nothing a cam wouldn't help though. If anything it would help you hook up on the street lol.

It is physically a big *** turbo though. Tough to fit in our bays.

Jay

1991sleeper

iTrader: (-3)

This could come in handy on a boost build ... Google high compression low boost Xcceleration.com

Technically on a 10:1 engine u can run 12psi boost with good tune on 93

Orr89RocZ

iTrader: (20)

I dont like that chart. Comp ratio really doesnt change as its just a ratio of cyl volume to compressed volume. Its set by geometries of components. Addin boost just changes densities of the mass flow goin thru motor

Clayton91

Iv seen that chart before but given I'll be running E85 only with this engine and its reverse cooled I didn't bother saving the chart to a file. I figure 10psi will get me where I want....for now.

@Jay....I figured Id have a bit of lag on the low end but Iv heard some people having traction issues(I don't know given this is my first 3rd gen) and Id rather have some lag vs choking the engine with a HX40W....unless I can find a t70 before new years lol.

@Orr89....Iv looked at my stock PM rods and done some research over them, from what Iv read their good for under 450hp. Would it be alright to reuse them given they would hold at TDC a little longer and have less stress on the side walls? Or would normal 5.7 rods be a better bet? Iv cleaned them up really well and cant SEE any cracks or chips, pistons and crank was fine so I doubt they was beat on much.

1991sleeper

iTrader: (-3)

If only planning 10psi I'd stick with 9-10:1 to keep up ur low end torque a little to compensate for the turbo lag ... I'm @ 10.7:1 and was thinking about running around 10psi myself just no funds for all that right now

1991sleeper

iTrader: (-3)

So what all changes need to b made to run E85 ? I've head it's extremely corrosive on the older fuel systems

Clayton91

I'll be around the stock 10-1cr once its together, maybe a tad less given I have to have a custom head gasket made anyway. To run the E85 you need a fuel pump and new lines that can handle it, Iv found lots of big name brands on summit that are compatible and not a ton of money(most can be ran with Diesel/E85/Gas). Im pretty sure you have to use a special type of injector?
Not sure if the normal ones can run E85 or very long :/ One of those questions Iv been needing to get out there lol.