ok guys.. i have a 88 TPI 350 in my IROC... and i think its time for a rebuild.

ive already got some basic bolt ons like MSD ignition, coil, and dist.. a BBK TB, and full exhaust.

if i do the 383 strocker kit thats in Summit: 3.75" stroke crank, stage II rods, kieth black pistons, sealed powe/speed pro rings, clevite chamfered bearings, sealed power gaskets and melling oil pump.

what kind of power/performance would i be looking at? specifially rough horsepower, torque, and 1/4 times.

also, what the hell are chamfered bearings? do i have a 1 or 2 piece rear main seal? and what cam do i need for this kit?

thanks in advance.

 

You have a 1 piece rear seal block being the car is an 88. Performance wise, you will do no better than the heads and cam you put in it. IF you put it back together w/ the heads and cam in the 350 now, you probably won't see too much of a difference, b/c those heads will choke the 383 to death, and the cam will act even smaller in the 383.

If you went w/ some heads and a cam then you can expect more than stock.

 

any suggestions on what to do then?

 

Can you afford some new heads and a cam?

 

increasing the displacement of the 350 block is not the best way to get good power out of it. The increased distance that the piston has to move forces the motor to turn lower RPMs than a similar build with less stroke. I say stick with 350cu in and just go with a very strong head and camshaft combo. If you want to increase the power from your internals directly, get a standard stroke alum forged set, very lightwieght and that will probably do you as much good, if not more good, than stroking to 383.

IMO, stroking only works well when you stroke an engine DOWN, i.e. taking a 400 block to make a 383. This increases compression and reduces the vertical motion of the pistons, allowing for higher RPM and top-end HP increases. Unfortunately, it doesn't work as well going from 350 -> 383 as it does 400 -> 383.

 

dammit... im so confused now.

how huch would a head and cam combo set me back? which ones are good, but REASONABLY priced?

would a forged crank and different heads and cam work better that a stroker kit?

the bottom line is that i need to rebuild my motor, and i WOULD LIKE about 400hp and retain the TPI look.

i found a 350hp motor on ebay for 2600.. brand new with a warrantee.

 

If you need to rebuild you have two options. You can do a stock type rebuild using your stock crank, rods, and a set of aftermarket pistons, be it hyper, forged or cast. What you are doing in a rebuild is replacing the cam bearings, freeze plugs, piston rings, main and rod bearings. Any machine shop can do that for you, and you could probably get out for around $500 in machine shop costs, and the price of pistons. You could also do a 383 setup, which is gonna cost you more in the long run as far as rebuilds go.

IMO you best bet is the stock type rebuild, w/ forged pistons, and a set of Vortec heads and a COMP cam. The heads and cam will run you about $800 for the combo. That will get you a 400 crank hp motor...

 

Complete, absolute bunk.

Increasing the displacement is the best way to improve power. Increased displacement via increased stroke will lead directly to higher torque at any given RPM. Since TPI produces torque below the 5252 torque/horsepower crossover line, increasing torque is the perfect way to increase street horsepower.

Of course, increased displacement requires an increase in induction flow. Porting the plenum and base (or aftermarket base), 52mm TB, and aftermarket runners will improve the flow and move the powerband up to about 5500 RPM peak - perfect for a 383 street stroker.

Porting the stock heads and improving the cam with a 5500-RPM peak computer compatible roller unit will complete the package.

One-piece rear main 3.75" stroke cranks are available, and typically have the advantage of being internally-balanced, so the need for 400-style damper and flexplate are eliminated.

Depending upon how much work you can do yourself, you can build this engine for around $3000. Plan on needing exhaust and traction upgrades too, though. The MAF TPI may meet its match, but as long as you don't try to go crazy with RPMs, it will keep up.

(For you 383-rev nay-sayers, I know a "few" racers that run them. One in particular has 5.12 gears in his '57 Nomad, crosses the line at 6800 RPMs here at Bandimere, and 7200 at Pomona. And, for the record, the shortest BBC factory stroke was 3.76".)

 

if you want the 400 hp mark, you're going to have to sacrifice a good bit of low-end torque, or have a monster cam with a big *** intake, or go forced induction.

I would look into Vortec head and intake kits. I haven't had any personal experience with them, but i certainly have heard good things. The heads breathe like crazy and will be good for a good-sized cam. Also, you'd need to do something with your exhaust, becuase you can't push a bunch of air and fuel on the intake side without giving it somewhere to exit. Headers are a must, and a full exhaust certainly prefereable. The vortecs will set you back about $1500 for the head and intake kit. If you go aluminum, it's a bunch more.

If not that, you can look into the StealthRam or MiniRam intakes. Both have a good power range that will work well with larger camshafts. They also have a similar look to the TPI. They are about $350-$700 depending on what you get and who you go with. Also, you'd need heads, which you could port the crap out of your L98 heads, or you could get Eldebrock or other aftermarket heads that mount just like OEM specs. Most companies say which intakes they work well with.

Also, with the cam you'd need, your car is not going to be very user-friendly. Electronics and lights are probably going to pulse when your engine idles and such. 400 rwhp is nothing to small in a thirdgen.

I haven't got muy car totally finished yet, but i'm right about (estimated) 405 horses at the flywheel, which translates to about 320 rwhp. My build isn't anything too huge, just the LT1 intake and a pretty big cam with the necessary components to run it (headers, dual exhaust, etc.)

There's lots of options, just take some time to research an intake and head kit that you like and can afford. The cheapest way to go is probably the stealthram. Also, you can see the LT1 conversion that is similar to mine at www.lt1intake.com. You just have to know what you're shooting for, and if it's 400 horses it's probably going to take some time to find just the right stuff.

The last thing i mentioned was forced induction, which would require all forged internals and a great deal of fabrication. The results are always astounding, just know that your car would be in the garage for a year and cost you well over $5K when done right.

 

yes, but increasing the displacement via stroking is NOT. We're talking horses not torque. And the 350 block does not leave you enough room to bore it. Ask yourself, why does a tiny, crappy honda motor make 200 horses? becuase they have very minimal stroke, and thus redline at like 9,000 RPM. I'm not saying it's impossible, it is just not the best way, IMO.

Also, the BB motors are a different breed than the smallblocks. It doesn't suprise me that they had a much larger stroke, but i think that achieving higher RPMs with a standard stroke will lead to a longer-lasting and more powerful SB motor in the long run.

 

ok, well forced induction is out of the question, because i have enough of that in my other car (twin turbo).

so, im looking at say: vortec heads, comp cam, keith black pistons, and stock rods and crank. then i can leave porting the intake (or aftermarket) till i have more money if i have to.

i cant bring myself to tearing out my motor, and putting it back together STOCK... that just SUCKS! would i be happy with this above combo? would i need 24lb injectors.. bigger?

oh yeah, i already have Eldebrock headers, high flow cat, and Flowmaster cat back with a 2 chamber... exhaust IS NOT an issue.

thank you all for your patience with me.. oh yeah, heres a pic of the car in question.

 

And Hondas are the "same" breed as small blocks?

What exactly do you think horsepower is?

Crazy, forget the Vortecs. Spend your money where it will make a difference. Vortecs require more $'s that could be spent making what you've got make the power you want.

Incidently, how did you come up with 400 HP?

Regardless, a 383 will make it there a lot easier and with less money than a 350 will, especially with TPI on top. Or, in the world of reality, a 383 will make more power than a 350, all other things being equal, with TPI.

(BTW, TPI will make it harder to get to 400 HP.)

 

NICE ride! Well worthy of a great motor!

Be careful with the Vortech heads though...on many of them, the angle and bolt patterns are different and would require and after-market intake to match. Good luck with your build!

 

All Vortecs that will bolt to 1st gen SBCs require a special aftermarket intake manifold due to different bolt pattern and relocated ports. Hence the extra $'s.

 

I totally disagree w/ this statement. Are you trying to say that a high revving SBC will last longer than a lower reving SBC? I know people like to destroke a 350 to a 327 and spin the heck out of it, but IMO I would much rather have a lower revving, higher cubed 383 than a 327 IMO. Revving a motor higher is killer on bearings. Where the 383 has the 327 or a destroked motor like it, is in the area under the curve, and average HP and average TQ. That is key on a street car.

 

I do not appreciate the insult. I am well aware that Hondas are not the "same." It is becuase of moderators like yourself that i frequently opt not to post anything, and most likely shall not post anything henceforth.

While i cannot regurgitate numbers and specs on many motors as you seem to be able to, i am fairly certain that i know my physics very well. The piston in a stroked motor has a greater distance to move from top to bottom (which is where the displacement increase comes from,) which limits it from being able to move as rapidly as one with less distance, namely, the stock crank. This also increases the amount of internal resistance in the engine. These two problems are costly to overcome, because one would have to build a very light-weight assembly to gain RPMs, and also run rather loose to reduce the resistance. This cost difference, if used aptly elsewhere on a standard displacement motor, could produce more performance.

Perhaps this is an incorrect inference, but i do not think i am ignorant. Your "reality" statement was a little uncalled for, since i feel that i have been very clear and accurate with my comments.

 

no, i actually agree with you, i was meaning that running a 383 and a 350 at the same RPM, the 383 is going to die much much sooner. The thing is, with the higher reving motor, i think you can do a lot more cam and intake work to get those high numbers. Many super-high lift cams don't live in lower RPMs. Remember that the area under the curve of the lobe is also a key determinant.

 

I don't necessarily think it is going to die much sooner than a 350 RPM wise. It will w/ the same cam b/c the same cam that in a 350 spins to around 6200 will make peak power in a 383 at more like 5800 b/c of the added cubes. The extra 33 cubes will make a cam act a lot smaller than it would in a 350, thus cutting down how high it spins. It will however make more power throughout the band, and make more peak power, at yes a lower RPM. But that is a non issue b/c you have mroe average power, and more peak even if it is at a lower RPM spot.

B/c the added cubes make cams act smaller, people run bigger cams in a 383 than you would in a 350. Thus even more power, w/ the same idle qualities and drivability out of a bigger cam in the 383.

 

i dont really know why i picked 400.. just seems like i nice round #.

what heads should i lean towards? AFR? ive heard the DART iron eagle heads are good.. are they?

i needto figure this out, and do it QUICK.. cause im scared to do any more damage to the motor before i can fix it.

 

If you are on a tight budget, the Iron Eagle are good from what I understand. If you can afford it, then AFR or TFS is the way I would go. I got TFS heads for my 355 I am building...

 

There was no intent to insult, just to counter inappropriate advice and shakey information. And, you brought up the Honda. I wasn't directing the reality part towards you, but to the TPI issue.

Okay, back to all the recommendations offered thus far: Let's not forget Crazy wants to keep the TPI. That makes things like high-reving destrokers and super high-lift cams inappropriate. It also makes power more expensive, but it pays back with nice driveability and fuel economy. If budget is a concern, ported stock heads, properly upgraded with springs & screw-in studs, are the best route. They will make as much power as the MAF TPI can support.

A cam upgrade and TPI improvements will make quite a difference on a fresh 350, even. So, don't assume you have to go radical to get there. In fact, going too radical will lead to disappointment, so caution is advised to keep the "package" balanced. If you go radical, you're going to have to convert the TPI to speed density, which will drive up expense, but has the advantage of more flexibility in PROM tuning. It will also support a 383 better and make getting to 400 HP more likely.

 

Thank the Lord for growing up - getting married and having some kids will do a lot to put distance between me and my college angst!

My comments above are way, way off in many ways. I saw these posts in my User CP, winced at some of the things I actually posted, and just wanted to ensure (8 years later) if anyone searched and found this thread they completely ignored practically everything I had previously posted.

 

Good idea for ALL of us to keep that "learning" thing going all the way until we drop into our grave
It was big of you to come back in here to recant!