305 Help

[tfreer85]

Well it seems that the shortest stroke that Eagle makes is 3.250" to be used with a 5.7 Rod. I don't know if that gets me close to a 302 to or not I think its closer to a 327. But close to $700 for a 4340 Crankshaft seems kinda high, for just a crankshaft (I could be wrong.) http://www.eaglerod.com/products/Chevy/small%20block/SBC%20cranks.html

 

Heres some interesting ideas on getting a 302 from a 350 block http://www.beckracing.com/page17.htm

 

More research on the way. I don't see why everybody makes such a big deal about the pistons? Especially since its standard 350 bore. Is there some connection I'm not seeing here?

 

Jack as for the dad seeing mild (in cubes) and actually being mild is different. I want to pull as much hp as possible out of fairly small cubes. And you're right there is a lot more involved to mess around with OBII, so that bumps out the 4.8L Truck motor.

 

Tyson

[jack46]

Jack as for the dad seeing mild (in cubes) and actually being mild is different.

Well I do NOT want to help you deceive dad. If I were him I would look at block see 5.7 and ignore internals.

 

I suggest you sit down with dad, and say here it is an LT1 with a small cam 214/224 .460"/.480" LSA 112 (regrind costs ~$100, small lift uses stock rockers), will get you a SOLID 300 - 315 RWHP and should pass smog.

 

It will get good mileage probably >20 mpg, and allow you to do one conversion. It would be ~12.5 sec 1/4 so no changing later.

 

I want to pull as much hp as possible out of fairly small cubes.

Talk to him and both negotiate and simply do a mild 350 LT1 or whatever engine. CHEAPER to do it once. CA smog is TOUGH to fool I THINK a 214 would work, I have HEARD a 218/226 (Hot cam will pass).

 

VERIFY verify verify!

 

And you're right there is a lot more involved to mess around with OBII, so that bumps out the 4.8L Truck motor.

MAKE sure that is FACT. People talk I am biased toward LT1 talk to someone biased toward LSX to make sure there aren't similiar packages for LS.

 

NEVER accept a few peoples opinion. Too easy for anyone to be wrong. No one intentionally misguides you, but they still might point you in the wrong direction.

 

Seems this thread has gone full circle. I definately think you need to get dad on board and build an engine you accept 300 RWHP is ALOT and still a GREAT daily driver, look at signitures 280 - 325 RWHP is what most use in a daily driver Z!

[wheelman]

The newer tuning programs can all handle OBDII but they cost more. As far as I've been able to gather the primary difference in OBDII is that it's much more picky about all the systems being operational, but I've never dealt with it so take that with a grain of salt.

 

As for the LSx series truck motors. I believe they can be swapped but it will mean replacing the oil pan and intake with those from an LS1. The truck blocks are iron instead of aluminum so no real weight advantage but you do get aluminum heads and the newer technology. Hood clearance is the problem though and thats what forces the LS1 intake swap and you still get to deal with the OBDII computer and LSx series electronics. To pass CA smog you'll need to have all the systems there and operational including the catalytic converters and the rear O2 sensors. At least your dealing with a 280Z that had a CAT to start with so thats doable. I've only heard of one Z with an LSx series truck motor swap and the last picture I saw it didn't have a hood.

 

My suggestion mirrors Jack's. Sit down with Dad and negoiate. I'm closer to your Dad's age so I know how he feels, he wants you to concentrate on school, have a mild car so you don't kill yourself but that is still cool enough to boost your ego a bit. Maybe understanding his position will help with the decision making.

 

Who is financing this project?

Who is financing your school?

In the end the guy with the money makes the decision!!! If thats you, consider the trade offs you make when spending money on a car vs. other things and how it can affect your future. Doing the less expensive swap now and then upgrading in the future after school is completed is not a bad way to go.

 

Wheelman

[tfreer85]

I'm not asking you to help decieve my dad. Its not my intention, what I mean is that I'm not going to be radical. And the way he sees HP is based off of cubic inches. I did some research on some Camaro Forums about the OBII last night, its not just the slightly more complicated tuning but there is an increased cost for the parts. (newer market) I'm sitting down with my dad today and going over the options (hoping I have some levearage over him because its my b-day). I'm going to talk about the 350LT1 First bone stock, if no then go to the 327 LT1, if no on that then the 305TPI, and if no on that well it doesn't look like I'll be doing a V8 conversion any time soon and would be looking into different engine options AGAIN... As for you pushing the LT1 I've seen it, but considering its the FI system that I've been leaning to throughout the majority of this post its all good. That being said I'm not blindly following just yours nor anyone else who chips opinion, I am taking into account that you seem very well versed into cars, camaro engines, etc. and do GREATLY APPRECIATE all of the help. Going to try and find out about the Smog regulations or try to get a Smog book instead of going by the "Well its this"..."No, its this" sort of thing which unfortunately happens.

 

Wheelman bout time you chipped back in here. The largest cons I see against the LSx is the cost $3000 for a half cut, and the harder OBII. I see an LT1 as being a better setup to go with. The beck racing setup i think is what you were want to do with the Caprice internals to get that 302 of yours. I understand the from a Dad point, however I'm paying for all engine work and mods, and even partial cost of the body mods. He is going to be taking on the brunt of the bodywork costs. However I still fall under the "not under my roof situation." which lends itself to problems. Well i'm off to lunch so I'll be while before I can reply.

 

Tyson

[jack46]

Ok ROUGH Hp ratings

 

4.3L 200 RWHP

305 220 RWHP

350 260 RWHP LT1 (Iron headed stock from Caprice)

350 285 RWHP LT1 (Aluminum headed from Camaro many Vettes rated 300)

 

going from Caprice to Camaro HP is really just a Cam. Aluminum heads flow better for larger cam's, but stock about the same. So best compromise for all since a cam, different MAF and you get higher RPM and 285 RWHP.

 

Beauty of stock is NO reprogramming required, and WILL pass smog! So You wouldn't NEED any of the software!

 

And MPG SHOULD be >20 I don't check mine I guess it to be >20, but I have 4.11 and with automatic.

 

Also can point out to Dad that with tools mentioned he could set rev limiter on LT1 until he 'trusts' or feels confident in your driving skills. He could set it to say 4500 and then car has <200 RWHP. You could negotiate he keep software until x miles or y grades etc. Some achievement he accepts, or even only lets the rev limiter removed when you go to track!

 

Be creative. Make it a win win all he wants is to get you a reliable. safe car that is economical.

[tfreer85]

I had never thought about setting rev limiter and that such some very good ideas to help me gain his trust. Thats not bad hp gain for just a cam and MAF. I want to have something clarified. The heads on the 5.7LT1 if they were to be put on a 4.3LTI would drop the compression a lot correct? Could this be solved by upping compression with the pistons? This website http://www.automotiverebuilder.com/ar/ar99928.htm says that the heads are not interchangable at least going from the 4.3 to the 5.7 but what about vice-versa. I'm not looking into swapping on the new heads since you've stated its not worth the money, but would like it clarified. Do you have to worry about the 5.7L valves hitting the block because of the smaller bore on the 4.3L or what? One more question for you, do you have a software program that allows you to calculate these numbers or are you doing it all by hand and knowledge? (I'm not questioning the legitamacy just would like to play with numbers myself),

 

Tyson

[jack46]

Thats not bad hp gain for just a cam and MAF.

 

Yes iron headed are often A LOT cheaper, but performance is ~ same.

 

I want to have something clarified. The heads on the 5.7LT1 if they were to be put on a 4.3 LTI would drop the compression a lot correct? Could this be solved by upping compression with the pistons?

 

Pistons COULD but since no one makes parts for 4.3 doubtful other than custom pistons and that means one of a kind and EXPENSIVE! And smog probably will FAIL with different pistons! Hard to match GM or any manufacturer. There is little or NO free hp in most engines.

 

STOCK LT1 is ~10.4 putting the 4.3 heads on an LT1 would raise CR BUT drop hp because they have smaller valves and won’t flow as much as real LT1 heads.

 

The LT1 on 4.3 or 3.74" bore would hit the bore. It is like larger heads on a 305. Can be made to work but note the 4.3 had 9.5 CR with small chambers so could never exist with the larger LT1 chambers.

 

LT1 are small I have a set from 93 Camaro and they are 52 cc later Im told are as large as 58. Iron ones I have seen 5 sets have been 60 cc.

 

Look here for on line calculator

http://www.cprparts.com/ci_calc.html

 

Et’s hp = RWHP weight is WITH driver. 1/4 = 1/8 * 1.583

 

http://www.race-cars.net/calculators/et_calculator.html

 

For HP etc I have a few desktop dyno’s to do some what if’s. There are some free desktop dyno’s on line. They should be viewed to be a comparison of two alternatives NOT absolute numbers. Many estimates are based on 30 yrs as an engineer. SWAG.

 

SWAG = Scientific wild azz guess

 

Always question numkbers some are simple estimates and have high error. The stock numers are as pulish and generally accepted. They are NOT accurate. LT1's are said to average ~260 RWHP not 285, 260 is more like 240 etc. Numbers often represent the best of a family not the actual as shipped. Like gas mileage often the best you will get NOT what most get.

 

Think I need to let others post I don't want to hog, sorry if I did. but YOU need other inputs to get some balance. I am BIASED toward LT1.

[80LS1T]

Well I dont agree that the LT1 is a better engine than the LS1 but its is deffinetly cheaper because of the LS1. No one wants to use the LT1 anymore if they can afford the LS1. Which is great for the guys that are on a budget but want EFI for a decent price!

 

I also dont think that "upgrading" to a bigger MAF is a wise HP/Dollar move. You wont see any significate gains and in my opinion its a $300 paper weight! Descreening the MAF is also not a very good idea, IMHO. You want a smooth air flow over those wires running though the MAF and descreening it tends to cause

the MAF to give poor reading due to the more turbulant air going over it.

 

I say get a bone stock LT1 with alluminum heads(save on weight) put it in and drive it like that. It will beat most cars on the road just like that. Once your out of the house and on your own you can upgrade it later with a heads and cam package that suites your needs. Plus it wont require any special tuning now.

 

Just getting an EFI motor and tranny in the car and running will cost you a pretty good chunk of change. You need to think about all the little things that will nickle and dime you to death if your not ready for them. If this is a budget build your going to need to bargin hunt and stay away from the "bling bling" items.

 

 

Guy

[jack46]

Well I dont agree that the LT1 is a better engine than the LS1 but its is deffinetly cheaper because of the LS1.

The best solution meets all requirements for the least TOTAL cost! Total cost is life cycle cost! I guess you were trying to discuss

 

The largest cons I see against the LSx is the cost $3000 for a half cut, and the harder OBII. I see an LT1 as being a better setup to go with.

 

I also dont think that "upgrading" to a bigger MAF is a wise HP/Dollar move. You wont see any significate gains and in my opinion its a $300 paper weight!

Since I stated an after market MAF is a waste of money you must be agreeing with me? To review, an ironheaded MAF is 3", upgrading to an aluminum headed 3.5" MAF is cheap, I bought one for $30.

 

If you use a Camaro Cam do what GM did and use the larger 3.5" MAF, this also avoids reprogramming.

 

I recommended an Iron headed LT1 with a Camaro MAF and cam. Aluminum heads save ~50 pounds, but a car going 12.5 second 1/4 mile only needs ~5 RWHP to make up the 50 pound weight gain.

 

Aluminum heads are simply not cost effective, I bought an entire iron headed LT1 for $350 with harness and ECM. Aluminum headed motors cost about three times more because many falsely believe aluminum are superior. Also the Camaro cams usually cost ~$25 shipped!

 

People think so little of non aluminum that I was given a set of iron LT1 heads so I have a 2.02/1.6 heads for my supercharged LT1 for total cost ~$100 (valves, screw in studs), and a few hours of my time to do the machining.

 

I don’t agree with an electric water pump on the street, too expensive. They cost ~$150, and only enable using an old style timing set? Stock chains are FINE for street cams and springs, and the chain is about $35 and will add the same zero hp.

 

Also, try breaking down in some small town, I bet they have a stock LT1 water pump on the shelf. Why pay to decrease reliability and maintainability, for no performance?

 

Between the money saved on aluminum heads, and an electric water pump I will have ~$450 and need ~5 RWHP to match the recommended non bling bling approach. I would buy the gee whiz software, and cold air intake and gain probably 10 hp and have the software toys to program mine and other's cars. People pay to get data collected and tune changed, few pay to see aluminum heads or other shiny bling bling parts.

[jack46]

Descreening the MAF is also not a very good idea, IMHO. You want a smooth air flow over those wires running though the MAF and descreening it tends to cause the MAF to give poor reading due to the more turbulant air going over it.

If you leave the stock rubber accordion on the intake you are right, the air tumbles constantly, and the screen is needed. If however, you have a decent intake that is probably not the case. I have collected data on a few LT1's all gained power (faster track times), and flowed more air in TTS Datamaster.

 

From another site “... tested by a MISSL member on a flowbench ...

The stock MAF ... flows 556 cfm. Removing the screen is good for 650 cfm

 

Stock MAF should flow a max of 308 g/sec.

Stock MAF w/ screen delete, max of 359 g/sec

48mm TB, max of 349 g/sec

48mm TB w/ airfoil, max of 365 g/sec

52mm TB (780cfm), max of 431 g/sec“

 

So from this data it seems the airflow bench supports that the MAF as GM thought can be a restriction. IF you use a smooth intake, mandrel pipe you will avoid air turbulence. Mine cost ~$60 plus aluminum 'snorkel', air filter, and located the intake in front of the radiator on my Z. Pipe from O Reilly’s. Want to compare the HP change from an engine that draws air from in front of the radiator (~30 degrees cooler), and increases the available CFM to some other ~$150 recommended changes?

 

I want to see data supporting MAF statements. I have heard how descreening made no improvement, caused split BLMs, etc show me data. I would like to see an engine making enough HP to cause a vacuum at WOT, and when a descreened MAF was used air flow went down or caused split BLMs.

 

I did NOT believe in removing the screen on a MAF, but the data I have collected, and seen shows it usually does help engines. These engines often only have a few modifications, IT will NOT help all motors breath better, but if there is a decent intake, exhaust, then yes it probably will help.

[80LS1T]

Yes I was reffering to the aftermarket MAF's. I dont have any hard data to back up my opinions but after reading threw post after post about how a aftermarket/descreened MAF is making their car run wierd I decieded that there are better things to speed money on to make more HP/TQ.

 

As for the electric water pump, I personally dont like the idea of a shaft running from my water pump to the timing chain cover. Its not really a HP mod but more of a piece of mind mod for me. Your right about not having a water pump locally. I never even thought of that. Although I do like the idea of changing my water pump is about 10 minutes! LOL

 

I wasnt telling him to buy an electic water pump or not buy a differnet MAF. I told him he should stay with the stock set up and then upgrade later to stay on a good budget now.

 

 

Guy

[wheelman]

Jack,

I have to disagree a little concerning the descreening of the MAF. The airflow restriction caused by the screen isn't the whole story, the MAF calibration gets messed up when you remove it. I know there is a controversy about this and I don't have hard data but like 80LT1 I've heard lots of stories about descreened MAFs causing strange behavior. It's possible to recalibrate after descreening but it takes alot of work to get the frequency curve built and doesn't seem worth it to me unless you're making tons of HP. In that case you probably aren't running the stock PCM anyway as it can't handle high RPMs. I also don't think you get smooth laminar airflow in any intake no matter how smooth it is, but this is just my viewpoint and I'm not an expert.

As for running a 3.5" MAF with an iron head LT1 not requirng programming, thats not true either. This is exactly what I'm doing and when I first installed the larger MAF and left the calibration alone the engine ran pretty rough because it thought it was getting more air than it was, ran rich in other words. Once I took the MAF calibration from a Camaro file I have and added it to my setup it ran just fine. This is only my personal experience but it makes sense and my opinion about descreening is based on this.

I do however recommend upgrading to a stock 3.5" MAF as it really lets the engine breath better at higher RPMs, just remember to reprogram the PCM to account for it.

 

Wheelman

[jack46]

I have to disagree a little concerning the descreening of the MAF. The airflow restriction caused by the screen isn't the whole story, the MAF calibration gets messed up when you remove it.

I have seen many make this boast, but NO one has shown any data to support these claims. I know it feels good to believe it. But if it is true there should be data to validate it's truth.

 

Doing a Kabookie dance to drive away evil spirits when our cars don’t run properly is fun, feels good, and successful! I can bring thousands of tribesmen to verify it's success? Look at large number fallacy.

 

I know there is a controversy about this and I don't have hard data but like 80LT1 I've heard lots of stories about descreened MAFs causing strange behavior

I have heard them also and challenge ANYONE to show data from one that caused these stated evils! I want to believe what is right, I won't change my beliefs because someone says something. I am an engineer, so show me the data. If it can't be verified, I will not believe it, and do not understand why others can believe.

 

To date no one has shown me a datamaster file that showed a MAF problem. I did NOT say there isn’t one, but I want to see before I believe, especially since I have data supporting the opposite.

 

I have also been told that you can install an early opti 180 degrees out. Ever try it? It is impossible, but the myth is alive and I see it claimed all the time.

 

It's possible to recalibrate after descreening but it takes alot of work to get the frequency curve built and doesn't seem worth it to me unless you're making tons of HP.

I have NEVER had to change the MAF tables! The other day I tuned a dual turbo LT1 with 306 cam, headers, descreened, and ported MAF in ~hour.

 

When I first collected data the Block Learns were 154/160. The eventual changes were slight, and were made to the idle trims NOT the MAF tables. When tuned the BLMs were close to perfect 128/128 and idles at 825, the settings just take alittle patience, experience and knowledge.

 

Why was the tune off? He changed injectors and only changed the injector size.

 

In that case you probably aren't running the stock PCM anyway as it can't handle high RPMs.

LT1 ECM is fine to RPM levels of a 350 why is this mentioned? Seems like a smoke screen?

 

I also don't think you get smooth laminar airflow in any intake no matter how smooth it is, but this is just my viewpoint and I'm not an expert.

Laminar flow more smoke? This is how all discussion of MAF digress there is of there isn't data to support claims why believe them?

 

Back to the discussion. The MAF screen deleted will not correct a poorly running engine, and won’t hurt a properly running engine period.

 

As for running a 3.5" MAF with an iron head LT1 not requirng programming, thats not true either. This is exactly what I'm doing and when I first installed the larger MAF and left the calibration

That is WRONG.

 

I said do as GM did use the larger MAF with the cam. You use the stock program for a 3.5 MAF called a Camaro tune.

 

This is only my personal experience but it makes sense and my opinion about descreening is based on this.

I know it ‘feels like’, and many ‘believe that’, but that is simply wrong. When your beliefs are contradicted by facts, maybe it is time to review your beliefs.

 

In God we trust all others show data, and pay cash.

[jack46]

PS I know what is coming next. Testomonials, and butt dyno's.

 

No they are not valid data. Then somone says well look at this data, which is usually created and stated: What if the MAF data...Or I heard...I read...I know a guy that...

 

Collect data from a REAL engine running not simulated. I DON'T care about the myths you heard, you believe, or you spread. At this point with no data the discussion usually changes to an argument and I wish all well, but don't expect me to respond.

 

We are supposed to be adults, and capable of making up our own minds. Your beliefs do not affect me. You can believe the moon is made of swiss cheese, the world is flat, etc as long as you don't say I believe it, or I stated it, I dont care. If I am not misquoted it is time for me to move on.

 

Good luck

[wheelman]

OK, I guess I'm done with this discussion also, sorry for hi-jacking the thread.

 

Wheelman