kyle97

grammerman,

My brother recently built a similar setup with similar goals - a torquey daily driver that would be reliable and get decent fuel economy. He was also on a very small budget:

A4, 383, ~10.5:1 compression, cc305 (220/230, 114lsa, so its close to a hot cam) with stock heads(not even a valve job )/LT4 springs/stock 1.5 rockers, shorty headers+borla, cold air kit, stock everything else.

We are still breaking in the engine, so we dont have any performance data yet. I will say that even with this "smaller" cam, the idle and driveability of car doesnt feel stock. We had some issues getting it to idle properly and preventing it from dying coming to a stop. I'm definately more into street-friendly setups (I've got a baby 210/224 in my 355 daily driver), so I would recommend you look seriously at the smaller cams aba383 mentioned.

grammerman

Thanks to the last couple posts that had helpful information that was actually related to my post topic. kyle97, your details on your bro's 383 build is appreciated. In a former life I used to install and tune Electromotive and Motec EFI systems and know a thing or two about how testy what some on here call "small" cams can be to tune at lower RPM's and especially at light load. The tradeoff in driveability with larger cams int the 230 degrees plus duration is not something I'm willing to accept even if some poor misguided soul calls it a towtruck engine.
94CamaroZ28, I appreciate your opinion on the valves not being of much benefit with stock heads but some of the other comments in your post beg to be used to stimulate discussion of what I think is faulty logic in many people's understanding of how to tune engines. Here are some of your comments:
"I really don't think you're making good choices for what you describe wanting from the car. 11 to 1 and 383 is going to need good heads designed for sufficient and EFFICIENT airflow for your shortblock, or you'll make far less power than you could, not gain any of the desired benefits, and wind up with a seriously inefficient engine that will give you poor fuel economy."
I didn't really describe what I wanted from the engine, but it seems clear enough from the parts I described that I'm not trying to build a race motor with a HP peak at 6500 RPM's. Seems to me like moderately ported stock heads with a 220'ish cam is a good place to be for a stout yet still responsive and efficient daily driver. I also don't understand why a 383 with around 11:1 compression demands big heads, it seems to me that the RPM range where you want to generate peak torque is the primary consideration that should be used to select heads and cams for that matter. If you want to concentrate your improvements in the midrange then a big cam and heads are not the way to go. Nor do I understand how moderately sized ports and a moderate cam on a 383 is going to cause "a seriously inefficient engine that will give you poor fuel economy." Efficiency could be defined as the amount of energy produced from a system from a given amount of energy input. The energy input here is gas and us knuckle draggers usually measure an engine's fuel efficiency as it relates to HP using a formula known as Brake Specific Fuel Consumption (BSFC). The combination I'm putting together would likely trounce the BSFC numbers produced by a big cam/big heads package at lowend/midrange RPM levels, thereby providing a higher level of efficiency. More HP per pound of fuel consumed equals higher efficiency, not being able to process more total fuel and air.
Anyhow, the point is that people asking for opinions don't generally appreciate being offered detailed criticism by others who don't know what they are talking about. Knowing that you can use big cams and big heads to get big horsepower is a no brainer, my ten year old could come on here and repeat that like a parrot. Having actually purpose built an engine that was optimized for midrange is something that some of the "experts" on here don't have a clue about.
Big heads and big cam is the way to NOT produce the kind of power I am going to the trouble to plan for.

sam pace

This is sounds like what I am building.
It's quite refreshing to see somebody talk about a purpose built motor.
I have to agrree, the more efficient you make your setup power will follow but,
you know alot more than what you are leading on to, and you already knew the answer before you posted.
Who are you?
I would like to know more about what you are building.

WS6T3RROR

I would have to say that bigger valves would be of benefit even with the mild engine you've described, IF you know enough about shaping and sizing the port to make it work with the valve. That being said theres literally not enough meat in a stock head casting to make it too large for a 383 period, and the ones i've seen set up to go 6000 rpm+ have usually been tickled with a welder. As far as cams go the hotcam isnt bad, but you can do alot better. Bring the intake and the exhaust durations closer together, add some lift and tighten the lsa up, i usually dont use anything over 110 for an lsa unless its in a big block and thats a whole new ballgame in every way. Most of the engines i do are for trucks that see extremely heavy loads or offroad duty with 44" tires, and even there the smallest cam i use is a 214* with a 108 lsa in a 350.

1racerdude

That's what I told him in an earlier post.
I told him he was building a tow truck engine and it would run out of wind about 5500.
He don't want advice.

OBTW BSFC is only used to tell the efficiency of your engine on the dyno along with the A/F ratio.
Didn't think ya were building a gas mileage queen for a contest.
I know ya ain't running NASCAR.

Fuel mileage/fuel cost and HP are not even in the same book.

thesoundandthefury

I literally laughed out loud at this.

Here's my advice: you see that little button at the top of your screen that says "Search?" Click it, and when the window pops up, type in the phrase "bolt-on mods." Read everything that comes up.

When you're up to speed, then come back and talk to us.

grammerman

There goes the lame towtruck reference again, sticks and stones may break my bones.... Since you don't seem to have caught on yet I'll repeat myself again. The point is to maximize midrange torque and throttle response with good top end. Top end or peak horsepower is a secondary and not a primary consideration. I realistically expect to get good power to at the very best 6000 RPM's and 5500 RPM's wouldn't be a deal breaker by any means. I also never said that max. gas mileage was a big consideration, if you'll go back and pay attention you'll see that I was simply giving the definition of increased efficiency to someone who claimed I'd be killing it with the package I'm considering. I wasn't stating my intention.
I may or may not go with a hot cam but it will certainly be something within a few degrees duration wise. I might decide to go with one of the newer cams with steeper ramps but won't be going with a big stick that will rev great to 6500 because it will hurt the PART THROTTLE torque and throttle response in the midrange and cripple the torque down low. I think I'll start a new thread on baby cams for street snap in the 383. You ever do any dyno testing and serious tuning at 1/4 throttle before and after cam swaps? I have, several times. I used to do dyno tuning and EFI installs at a shop in Birmingham called HESCO, since you're in lower Alabama you have probably heard of it. Dyno testing at part throttle sound crazy? Maybe if you're mainly concerned with peak horsepower.
I intend to build something with torque reminiscent of the tuned port engines, may weld up a long runner intake something like the LS1 to increase midrange torque. I had a 383 with a richmond gear six speed, Brodix heads and a high flow aftermarket tuned port setup years ago that was more fun to drive on the street than other cars I've owned that had considerably more peak power. A lot of people are interested in builds like this and a few people have actually done them. Those are the people I'm interested in hearing from.
I've been out of the game a while but used to be pretty far off into this stuff so I have a pretty good idea about what I want out of my engine. I enjoy constructive criticism that has a positive intent but name calling while ignoring the substance of the post is childish.

1racerdude

TPI QUIT running about 4500 and ya shifted at 5000,in case ya didn't know.

Game HAS NOT CHANGED all my rules were developed years ago and refined along the way.
So if ya had a plan then and knew what to do the SAME applies hear and now.

To make HP ya got to get AIR-FUEL INTO THE ENGINE that hasn't change since Moses was a baby so,there it is.

Good luck with your tow truck motor.

BTW I never won any races at 1/4 throttle so it never has been a concern when building any of my sprint car engines or customers HP builds.

med_reject

for a 383 motor, lt1 heads can never flow "too much" no matter what you do to them. Any money invested in the heads will help low, mid and high range torque and horsepower.

Bigger valves with a good port by LE, AI, or any reputable porter you may know of will help you reach your goal. As for cam selection, 220ish cam on a 383 will get you peak power around 5500 rpm (this is a huge generalization, so many other factors) and an ideal shift point at maybe 6000. You'll have awesome low range and mid range torque.

and LE1 cam will get you what you want. Excellent driveability (not stock, but close), excellent off the line torque and midrange torque that will last until a 6000rpm shift point.

grammerman

Hey med reject, how's the weather up there in Canada? I appreciate your input, you seem to have a clue about the subject of mild street motors. Thanks for the camshaft review, I may talk to LE about his cam. About the ported heads, flowing too much is not really something I would be concerned about but flow numbers are generally correlated to port volume and big port volume changes tend to affect the midrange and especially lowend torque output in my experience. My heads cc'ed around 165 cc's on the intake side and 65 cc's exhaust stock. After just the bowl work they went around 175 and 70 with the stock valves, these numbers would go up by 5 or 6 cc's with the larger valves and throats opened up to match. After widening the top of the runners and raising the roof a bit I suspect they'll go around 190 or so with stock valves and close to 200 with the larger valves. Exhaust should be around 80 cc's or 85 with the bigger valves. I've heard of some of the agressive port jobs running up around 220 to 230 cc's on the LT1 heads and I think the resonant frequency of a port this size might not be optimal for midrange torque production on a mild 383 with the LT1 intake. Not saying it would be a dog by any stretch, just wonder if the all out LT1 port jobs might trade significant low end/mid range responsiveness for a little top end considering the tame cam specs.
And racerdude, your reading comprehension just plain sucks. I never said I was even considering installing a TPI type manifold, in fact I mentioned possibly fabricating a midlength runner intake similar to the LS1 as I have considerable experience in that type of thing. You might be dangerous if you actually understood what someone was talking about. You keep talking about horsepower and I keep talking about midrange torque and responsiveness. It looks as if you're not capable of understanding what I'm talking about.
Any qualified opinions here on the heads?

1racerdude

You are already dangerous with your thinking.
Ya seem to understand nothing about cross sectional area, flow coefficient.discharge coefficient,port length,effect of CID on head flow,effect of small runners on a stroker, effect of cam on a small runner stroker,effect of DCR on an engine,JUST to name a few.
Yet ya want to argue and correct people who do know want to give ya their advice.Although your 'tude SUCKS they have tried. I would like ya to post documentation for your theory to making HP with the BSFC ,small runners,small cams small everything and post documentation as to the relative HP numbers to this theory. Then everybody can see if the theory is any good for making HP.




Can't help ya man.

Good luck on the tow truck motor.

sam pace

well....
If you wanna great head advice talk to Lloyd Elliot he has alot of info for you.
Here is his site, www.eportworks.com. he will get you up to speed on what works for your application.
for cam selection he can make one for you or,
here is a link on this site for cam selection from mild to wild
http://www.z28.com/forum/showthread.php?t=58050
Here is the one I have:
CCA-07-466-8 -- 218@ .570/ 224@ .565 (1.6RR)--- 113 LSA --- 1800-5800.
You mentioned you wanted to make 350 at the crank. The only problem is that a typical bolt-on 350 makes that.
A "conservative" 383 is more like 400 to 440+ at the crank with TONS of torque. Lloyd will even tell you this!
A 383 will eat up 5deg of duration so a conservative cam is in the mid 220's.
This is what you are looking for right?

grammerman

Sam, thanks for the input. Are you running that cam in a 383 and what type of head setup are you running? Automatic or manual, stall or stock converter and how is the driveability? The 350 horsepower number was just thrown out there off the top of my head without trying to remember what these engines make. I used to deal with them a lot but always dealt with chassis dyno numbers when we tuned them so that's where the 350 number came from. As for racerdude, Uncle! Uncle I say! It's too painful! I can add another 3 dozen pseudoscientific hotrod terms I've read about in hotrod magazines too, but so could my parrot if I trained him for while. The parrot just wouldn't be deceived into thinking that a blob of big words conveys more information than a few correctly chosen broader terms. By mentioning the resonant frequency of the intake system/intake ports and being firm about not going with a big cam I've already covered most of the big words you just copied and pasted out of an online Chevy Performance article. The rest of the crap was covered with the consideration of a longer runner LS1 type intake (which still maintains a healthy cross sectional area) and straightening you out earlier on the lack of suitability of the TPI stuff which is a function of a restricive cross sectional area and a VE boost at too low a resonant frequency caused by excessive length. This is the second time you've mischaracterized my blurb on BSFC. I never said making HP was related to a great BSFC number, I actually said that high HP engines often have poor BSFC numbers at lower RPM's and light load. I must be pretty deadnuts on with all I've written so far. If not a supposed expert who's picking apart everything I say could do better than take things I say COMPLETELY out of context and then twist the wording to try to make me look dumb. I can tell you're not stupid because you know how to cut and paste big words so why the inferiority complex?
You keep talking about horsepower, now it's morphed into relative horsepower produced by using a moderate cam/ induction system. Horsepower has only been mentioned by me as a secondary consideration, it will fall within an acceptable range with the engine optimized for midrange. I still haven't heard anything I recognize as useful on making max. torque and throttle response in the midrange with still decent topend. You might still have something helpful to add so feel free to address the substance of my posts with useful information.

1racerdude

Post up that documentation and everybody might learn something.
Don't just flap them lips put up the documentation,if ya got it.

Can't help ya man.

Good luck on the tow truck motor.

med_reject

you guys are hilarious! grammerman, as mentioned Lloyd would know what sort of volumes you'd be looking at with all out vs conservative jobs (thats beyond my knowledge), and he's the guy who sells the LE cams under his name. Its actually quite hot where I am. Supposed to be 39 celcius this weekend