I'm after some info on the basic engine buildups from those of you who have upgraded your L98 California engines.

For me, the basic TPI 350 engine with enough mods to boost factory horsepower just past the 300hp and still being able to pull over 20 miles to the gallon seems like a reasonable setup for general street play.

I'm increasingly getting curious as to what the benifits or negative issues anyone has run into when they've started boring and stroking these 3rd gen vehicle V8's. Does boring .30 over or larger really add much? and at what point have you started noticing a drop in fuel economy/smog issues/longevity? Is going the 383 route really worthwhile for someone who wants to keep their F-body as a general purpose sport machine???

(Hopefully I explained that coherently....)

The reason I ask, is that my engine builder has been buried building a series of 15 engines for some race program and hasn't gotten around to mine yet, so I still have time to decide if I want to upgrade from 350 TPI hp and add a small blower, or nitrous, or fatten up the internals.
What I don't want to end up with is something porky that sucks 16 or less miles to the gallon, idles poorly, and dosn't cruise smoothly at speed. Plus, I want to keep the cost of the engine down near $5 grand.

Any worthwhile comments???? It would sure be appreciated.
Nitro

 

just rebuild your motor with forged parts add just about any aftermarket heads and a matching cam and you'll have 350hp easy with the right tune. you could also buy a long block with the power you want.

 

i would do a build with a 4 bolt main and fully forged with your choice of heads and cam and intake

why during my research its all the same price....

where your gonna get your gas mileage is in your cam, and tranny ie 6 speed swap

with my 6 speed swap i can get 28mpg's on the highway cruizing.

how ever i wouldnt go with a 383 for longetivity the stroke wont allow a 100K on it. just a 355 will do.

 

cough *BS* on the 100k.

The stroke won't allow it? Plenty of engines out there with many more longer strokes.

Hey Neagan, I've seen it before, and I believe in it, The power is in the heads.
Gas mileage and of coarse, idle, will be a direct reflection of cam choice.
If you can do forged, Go for it, If not, at least do forged rods, Cast cranks are fine for 500hp like the eagle cast steel crank. Pistons should be forged if you want to spray or boost. The more air you can cram into the cylinders, will net you more power.
So get some good intake and better heads. Headers, exhaust. The internals are your defense against hurting anything.

 

I'll definitely do the forged parts, although I'm okay to skip on the crank. I don'[t see myself coming close to the 500hp mark on this ride- I'm more after somthing light and quick. I have already seen the wisdom in going for a 4 bolt, higher nickle content, aftermarket block and the valvetrain design is going to be a lightened, hard hitting set-up that'll withstand any accidental miss-shifts.

It will be really interesting to see how well the small block will breath with all the CNC grinding 'Mike's Corvettes' did on the factory plenum, SLP runners, and matched up Edelbrock lower intake. The guy who's going to put together the final product builds actual NASCAR stuff and although it would have been cheaper to buy aluminum heads, he's going to actually take the time to show me how to do some special sculpting with a set of World Products iron heads. Interestingly, although I'm concerned with longevity and fuel efficiency, the heavy valve springs will probably eat through my camshaft by 100k miles.

The one thing that I have spent major amounts of time attempting to research, is the design of the exhaust. I'm really not much of a fan anymore of headers and was trying to find a way to avoid using any if at all possible. I was just sure there had to be a way to modify corvette 'Ram-Horn' exhaust manifolds to fit our F-bodies, but apparently it can't be done. Flowmaster's headquarter's are within 5 miles of my house, so I think I'm going to make an appointment with one of their technicians to come up with something strong and fairly quiet. I've already taken care of the 3inch full exhaust from the catalytic back...

One of the goals I have is to keep this as much of a visual 'sleeper' as I can get away with. I absolutely HATE getting pulled over, so what ever I can do to keep the cops from noticing me........ {Travis; that's why I want to polish up those factory IROC rims I'm buying from you- keeping a low profile}

But, back to the main subject: As far as doing the 355 or a 383- are there ANY disavantages to opening up the displacement? If not, then why don't more people make the jump if they're going to all the trouble of putting an engine together from scratch???????????? I know this sounds naive, but I just don't see the big picture yet. Obviously, the average hot rodder has a difficult enough time just paying for the engine parts, let alone needing to cough up cash for a 6-speed and modified rear axle assembly.

What I'm hoping you can find a way to explain this to me, is with keeping the rest of the drivetrain initially stock (which in my case is a 9-bolt 2.77 & 700R4). I want to be able to end up with a vehicle that I can occasionally drive up to the old family farm in Idaho without stopping at every fuel depot, and then take the nephews out to the local dragstrip for a few runs once I arrive. And on the way back, swing into the mountains for some back road high speed drifting.... Does that explain????

Will the 400 crank geometry on a 383 build reduce the 'sweet-spot' to a more limited rpm range? And will a 383 design limit the vehicle more to having to choose 1/4 mile runs OR staying in the 140mph club, instead of the versatility of being able to do both? I've always loved the versatility of the heavier sport touring cars we've grown up with, such as the 'vettes/300zx/SC400/ etc.; cars you could travel all day in and get out refreshed after a 8 hour high speed cruise through the mountains or deserts.

Is my dream to big????

 

wouldn't really reccomend a 383 if your gonna stay with the stock tpi design. even the aftermarkets wont flow enough air to feed a 383. although it would be a torque monster.

why would you not be a fan of headers

mileage,140mph, tuoring,1/4 mile: call who ever you plan to get a cam from and tell them what gears you have a what you plan to do or what you want the car to do and they should be able to point you in the right direction or even make a custom grind

 

With $5k you're damn near LSX swap territory IMO.

I'm more than happy with my 355 and when it was TPI I got quasi-decent gas mileage, but then again the real problem here is I drive my 'ROC like an a$$hole, the way it is supposed to be, so my MPG suffers terribly.

Headers are a must do, if you want to be part of the solution they make ones with AIR tubes.

 

The issue I have with headers is more of an issue with the F-body AND room for 'em. I tore up my back 'hella bad, and had to get a disc cut out and a metal replacement part this year. I just don't want to have to go crawling around underneath because a tube stress-cracked, or have to reseal, retorque, reinstall, replace, re-anything.

There's always someone who's had great luck with their set and have never had to touch them again once installed; but that's pretty rare. And then you have to pay attention to protecting your ignition wires and such. But; the factory design is pretty god-awful, expecially where it wraps around the oil pan area, so I've got to install something.......
Nitro

 

I would gladly help you with any exhaust issues!

 

a stock g92/n10 exhaust would suffice it yields a 15% power increase over factory there is no time change in my et in 1/4 mile going from the g92 exhaust to edelbrock tes headers, cat delete, and flowmaster muffler.

the g92 manifolds are bigger than stock and also the dual cats help.

 

no you just suck at driving

 

well i do suck at launching this damn 6 speed my my 60 foots have consistently sucked at 2.3-2.5 so they are comparable runs

 

Hi Travis. You have a strong reputation on this board for knowing what you're doing. I'd love to hear your input. I don't know what your new work schedule is, but when the holiday time's blow over and I come up to pick up those wheels, maybe you'd let me take you to lunch and pick your brain some?
I'm leaving town in just a few hours and will be back near mid January. By the way, I popped the Paypal funds for those and even threw in a few bucks to cover your Paypal costs.
Have an excellent holiday everyone! Nitro-Nicky

 

are you serious?

 

Hey hey my post quality might sometimes be in the gutter. But I do plenty of my own work on thirdgens!
give credit where it's due please

 

That's a far cry from knowing what you're doing though!

I like to consider you an explorer/scientist, going where no 3rd gen fan has gone before.

 

Ok, I'll agree on that.

wheres the cheers with beers emoticon?

 

Step 1: Mash gas. Step 2: Drop clutch.

Of course I can't talk because the few times I took my car to the track I was scared of parts breakage (stock clutch and rearend, plus it was my only car at the time) so I also got shitty 60 foots. Now I'm pretty much prepared to beat the crap out of it.

 

.....I didn't get much time this winter to do much to my IROC, other than basics like replacing the entire brake system, stereo, little nagging issues, etc. HOWEVER; I did take the time to install the bored out Plenum I got back from Mike's Corvette's and put in the larger Ford SVO injectors. I purposely left off the larger bored through runners and better intake manifold so I could do some real world testing of the breathing. I did 4 pulls and it showed a strong 13 horsepower increase to the rear wheels along with a fist full of torque!

I did order up the new engine last week, so have made all my part selections other than the exhaust manifold/header issue. I am hoping Travis and Pork (or anybody else knowlegable) are still linked to this THREAD and can maybe add a bit more to the exhaust solution.
I did a quick check to see if there's a Doug Thorley Tri-Y set that will work on our F-platform; they seem to be what the guys down the street at FLOWMASTER headquarters feel would be the number one choice, with Edelbrock down somewhere near a last place choice. Porkyzilla- could you expand a bit more on your
"stock g92/n10 exhaust would suffice it yields a 15% power increase"
comment? I think with the California Smog laws, I have to keep my factory one catalytic setup. My current exhuast is full 4-inch including a newer high flow cat.

....More Torque for me and my horses, bartender....

Nitro-Nicky

 

well dude you can go dual cat there is no problem with that.

hell you can have 8 cats if you wanted. nothing in california law says you can only put one cat on a car if it only came with one..

infact on my emissions lable it only stats twc meaning three way catalytist not x3 or twc twc, a technican will not fail you for having 2 cats.

but go with the magnaflow high flow 3 inch cats they are really good we used them at the shop produce good smog numbers and flow better than stock.

 

4" exhaust? must be mufflex? i just got myself a set of longtubes. i vote go with the hedman legal headers and have the y pipe chopped to accomodate the 4". do they sell 4" cats. im sure one cat will flow well enough if so. im just running a shell of a cat around my pipe lol

 

You should check CA's smog laws again. You cannot add a cat on a car/engine that didnt come with one, nor can you remove a cat from a car/engine that came with one. The only thirdgens that legally can have dual cats are the 89-92 models. You *can* change over an 89-92 TPI thirdgen from a single cat to dual cats and vice-versa, because that was an option for those years and models. But you cannot legally change an 82-88 thirdgen, nor an 89-92 TBI/V6 thirdgen to dual cats. If you dont believe me, I'll go searching on http://www.epa.org/ and http://www.smogcheck.ca.gov/ for you and find the specific laws. But I suggest you take my word for it.

By the way, I recommend Magnaflow cats too. The owner is a long time friend of my dad's.

 

Holy crap i've been gone a while

 

I agree with porky on this one. where does it say that you cannot add catalytic converter?

Porky, remember this conversation with Walter(BAR)?

The vehicle owner can add as many cats he/she wants. BUT, if the vehicle's underhood label says 1 catalytic converter, a shop can only put one. If the owner wants catalytic all the way to the tailpipe then go for it. The shop can only put the number of cats per underhood label(correct underhood label that is).

 

budget will dictate what you can build. for 5 grand though, you should be able to build a potent 383. i would definitely go with the 383. you don't need to have forged internal on this combo either. If you plan on adding any power adders in the future then back on the drawing board. Are you going to do the install? If not, then 5 grand will not cover it. Labor will at least take 2 g's.

 

 

yes exactly i remember that conversation

it was in regards to a blazer which had 4 cats haha

 

You can add a cat if you want. The law states that the minimum requirement is one or two cats as what the emission decal says.

The referee is the one who makes the ultimate call on what is legal or ok to have on your car.

My 82Z has a CARB sticker that says:

engine - 1970, trans - M, Emissions -PCV, TAC, FR, EVAP, and SPRK. So to say that you can't add or remover a cat is BS!

Now I know my car is rare to be able to get a smog sticker that has 1970 emissions but what my point is anything is possible! I do not need Air injection, cats, computer, egr, or any of the other parts not listed.

 

I did a quick search on CA's website http://www.smogcheck.ca.gov/ but I couldnt find anything on changing the number of cats, only on removing a cat completely, which we know is illegal. I have seen it before so I will keep looking.
Also, I remember a few years ago back in 2000 or 2001, Tom Keliher went to get his 89 Formula (dual cats) smogged, and the tech failed him because his car had dual cats. The tech's book said no 89's had dual cats, only 90-92. Obviously we know that '89s had dual cats, but the tech had to go by his book. Interestingly, the previous year's book listed 89's with dual cats, so it was a typo, but the tech still had to go by his current book. Tom simply went to another smog tech and the car passed with no problems.
So, if you're allowed to change the number of cats on your car, why did the first smog tech fail Tom's car?

 

well kevin heres the low down scoop

a tech can fail a car for anything and he wont get into troubble even if he is wrong.

and this has been discussed before with our bar rep in the area for the old smog shop me and bennie ran. and up int he qote is the bar reps exact words

it is not against the law, but a muffler shop can not install more than what was equipped.

and infact interestingly my emissions label only has one twc (three Way Catalytist) listed under my service parts identefication sticker N10 Dual Catalytic Converter System.

and G92 of Course

car has never failed for too many cats.

 

I had checked with my local muffler shop that does the majority of high performance exhaust systems when I had my current exhuast lengthened past the rear bumper. That's where I was told I can't do duel exhaust if it didn't come as an option in California. I've also heard stories where folks moving in from out of state had to 'correct' their exhaust setup back to a single?? Anyone else ever hear about that??
The car came with a new exhaust that starts out as 4" just before the new cat on back through a flowmaster.

Travis's comment:
4" exhaust? must be mufflex? i just got myself a set of longtubes. i vote go with the hedman legal headers and have the y pipe chopped to accomodate the 4". do they sell 4" cats. im sure one cat will flow well enough if so. im just running a shell of a cat around my pipe lol


Should I go through Jet Coatings to buy a set of hedman's? Or??

As for the engine install, I"m on my own for that. Since I"m recovering from spine surgery I'll probably have to hire out. I"m just hoping that the current 350 block holds together till I get the new engine preped for paint and figure out what sensors and accesories I should reuse from the old vs replace with new.
What I wish, is that I could afford putting a MARCH pully kit on the front! Plus I want to copy Travis on repainting the entire engine compartment before placing the new drivetrain in, although it looked like he (for those who've seen his empty engine bay) picked a real labor intensive way to do it. How about it Travis, have you posted any pic's of the finished engine compartment???

I'm quickly running out of cash: 5k for all the engine parts and machining/$600 for the alarm system/ $800 for all new brakes/ $500+ to upgrade the ray-dee-o/ ect. I suppose I better decide if I want to sell some of my extra shooting hardware or just park it for six or so months.......

Thanks guys for yer responses....
Nitro

 

I'm running late for work, but ill make a good reply to your post in a few hours neagan! (btw, when you coming up for that front clip?)

 

.....I'm late because I've been working on some great front '****' lately... (ha!) Speaking of which, i c it's lunch time.....
Nitro

 

UI think the hedman ceramic option is good enough quality, that you don't need to pay jet hot a few extra bucks to do the same thing.

My engine bay is ready for primer and paint, but its not painted yet, this wednsday I am putting on my front wheels and brakes, and then I believe friday, having the car towed up to placerville to my shop I work at to get finalized for real paint. then pics will follow.

 

Are you going to do anything 'fancy' with the paint design?? I'm really thrilled with the Chip Foose stuff and am considering how to two tone the area under the hood with a word or lettering or lightning boltz/Days of Thunder type of idea. I'm also giving thought to stripping the entire black exterior paint, adding the top of the hood, roof, t-tops, trunk that same blue 'Neil' has been using to build that beautiful Camaro show ride, and then doing silver from the doors down or something with European flavor
Nitro

 

No, I am just going a solid pearl red.