LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Porting LT1 heads Advise

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Old 12-11-2014, 09:24 PM
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I don't think it's fair to compare CNC heads to a set done with a die grinder. LE is cheap but you get what you pay for to an extent.

OP, if you really want to port these heads then do a little bit of reading first and keep the work minor.
Old 12-11-2014, 11:19 PM
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all iv been doing is reading for the last 3 months
Old 12-12-2014, 05:12 PM
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Originally Posted by Catmaigne
I don't think it's fair to compare CNC heads to a set done with a die grinder. LE is cheap but you get what you pay for to an extent.

OP, if you really want to port these heads then do a little bit of reading first and keep the work minor.
I didn't compare anything, but agree that the AI heads probably are better. But being somewhat new to this, I'm content to follow a logical sequence ... stock LT1 heads, TFS heads, TFS heads ported by LE, AI heads. LE does good work for the money and even though mine aren't CNC heads, I think the step up in performance will be noticeable and worth what I paid. I'll wait to try the AI heads until I go to spray or a blower.
Old 12-13-2014, 06:41 AM
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CNC isn't inherently better, it should be inherently more consistent port to port which I feel is important in port injected engines. With a carb if the ports are mismatched and flow differently the cylinder is getting it's air and fuel premixed, where sequential injection with bank to bank tuning all cylinders are getting the same fuel regardless of how much air they get and what is one cylinder really flows well? It would be lean when the banks average AFR is good.
The CNC master port was done by hand but the porter MIGHT put days into doing the masters getting them just perfect, then letting the machine replicate. Hand porting you have a guy waving a grinder around and I believe some are proud of doing a whole pair of heads in a day, 16 ports in a day. Doubting the shapes are terribly consistent at that rate of production. Sure there are some templates and such to help guide but still not going to match a good machine.
Then with a CNC even a good program is no guarantee, a sloppy operator can make a mess.
Old 12-13-2014, 09:03 AM
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The LT1 computer has tables for individual cylinder fuel offsets. You can tune each cylinder... Without a wide band in each primary you will not be precise though, and that is far more effort than the average LT1 guy. The intake manifold will create more cylinder imbalance than the minute difference port to port when hand porting.
Old 12-13-2014, 10:40 AM
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And those tables are NOT used at WOT and high rpm, if memory serves they are done at 2500rpm. GM put it there for emissions, economy reasons not max power. The tables are idle and off idle, no PE table I have seen. Hell I know a guy with 8 channel wide and on OEM OBD2 computer using rocker ratio and injector size to try and balance cylinders because even the OBD2 pcm won't do it at WOT.

It would be a special kind of stupid to "save" $300 on inconsistent hand ported heads only to admit needing an 8 channel wideband setup $$$$ to dial it in.
The intake and firing order certainly introduce some flow variation so I am not claiming a CNC head will be perfectly cylinder balanced, but it is one less variable.

There are hand porters who can be pretty consistent, they are not removing 30+CDs of material from OEM heads fast enough to be cheap.
Old 12-14-2014, 09:57 AM
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Originally Posted by 96capricemgr
And those tables are NOT used at WOT and high rpm, if memory serves they are done at 2500rpm. GM put it there for emissions, economy reasons not max power. The tables are idle and off idle, no PE table I have seen. Hell I know a guy with 8 channel wide and on OEM OBD2 computer using rocker ratio and injector size to try and balance cylinders because even the OBD2 pcm won't do it at WOT.

It would be a special kind of stupid to "save" $300 on inconsistent hand ported heads only to admit needing an 8 channel wideband setup $$$$ to dial it in.
The intake and firing order certainly introduce some flow variation so I am not claiming a CNC head will be perfectly cylinder balanced, but it is one less variable.

There are hand porters who can be pretty consistent, they are not removing 30+CDs of material from OEM heads fast enough to be cheap.
I did not realize those tables were not used at WOT, I never touched them.

Cylinder imbalance is going to be there with either AI or LE heads, If it matters that much to your setup you will tune cylinder individually regardless of porting method. The intake manifold has a far greater effect, and the minute differences with Lloyds hand ported stuff is not going to make a difference. The arguement would be valid when talking a lesser quality port job.

I had my LE heads flowed recently and they were very consistent port to port. I want to say within 5 cfm or less.. the flow sheet is at the shop with the motor, so I can't double check that right now.

It is natural to defend the choices you have made, which you do with a passion. Youre a loyal customer 96, but to most your AI is nauseating. Pay close attention in the coming year.. there may be a contender for the quickest cars out of the AI camp.. running shitty hand ported LE stuff
Old 12-14-2014, 10:21 AM
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I didn't say anything about either company directly you are the one trying to stir that pot.
Far as the intake introducing imbalance I said that but you are too interested in arguing.
What if the most deviating head ports fall at the intake ports that fall at extremes?

Like I said the argument I make is reducing one more variable.

Far as my belief in CNC, it is how I make my living, not a particular vendor thing.

Far as people switching from one vendor to another been done a bunch of times and at one point we had four people all in one thread saying they had used both and "there is no comparison" was what they all said.

If one person come up with a contrary opinion it is near meaningless because the inconsistency has been documented, only way it would be a valid argument/comparison would be to measure the exact shape and size of the port and see if that is the same as all the other customers get or if one set of heads got a week of attention vs. the standard day. With CNC everyone gets the same thing.

I am sure you will blindly argue that but tell me how you prove a single standout hand ported setup you hope will show up is the same product everyone else gets?
And again YOU are the one trying to turn this into a vendor vs. vendor thing, YOU brought that up, don't lie to yourself and everyone else and pretend it was me.
Old 12-14-2014, 11:29 AM
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Originally Posted by 96capricemgr
I didn't say anything about either company directly you are the one trying to stir that pot.
Far as the intake introducing imbalance I said that but you are too interested in arguing.
What if the most deviating head ports fall at the intake ports that fall at extremes?

Like I said the argument I make is reducing one more variable.

Far as my belief in CNC, it is how I make my living, not a particular vendor thing.

Far as people switching from one vendor to another been done a bunch of times and at one point we had four people all in one thread saying they had used both and "there is no comparison" was what they all said.

If one person come up with a contrary opinion it is near meaningless because the inconsistency has been documented, only way it would be a valid argument/comparison would be to measure the exact shape and size of the port and see if that is the same as all the other customers get or if one set of heads got a week of attention vs. the standard day. With CNC everyone gets the same thing.

I am sure you will blindly argue that but tell me how you prove a single standout hand ported setup you hope will show up is the same product everyone else gets?
And again YOU are the one trying to turn this into a vendor vs. vendor thing, YOU brought that up, don't lie to yourself and everyone else and pretend it was me.
C'mon now 96... Anyone who has been on this forum for a couple days know what companies you're referring to even if the names aren't stated.

I saw you agreed with the manifold, but then went on to bash the hand ported heads again. There is a small variable there, so small it is minute in this comparison. You would have some believe otherwise.

I'd like to see what the actual comparisons were when people switched vendors. I doubt runs were made in the same weather conditions, I doubt the cams used were the same, or had the same lobe characteristics, or valve springs etc. Talk about variables! It is not Lloyds fault most who purchase his stuff run a tighter budget. The car as a whole is the biggest variable out there - and is what will make or break performance with either vendor.
Old 12-14-2014, 01:06 PM
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maybe your join date is the reason you seem unaware of a LOT of documented problems, there is a history that you won't like.

The biggest reason for Lloyd's loyal following is he is willing to be a pal to everyone who dials his phone number.
Old 12-14-2014, 10:14 PM
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Originally Posted by 96capricemgr
maybe your join date is the reason you seem unaware of a LOT of documented problems, there is a history that you won't like.

The biggest reason for Lloyd's loyal following is he is willing to be a pal to everyone who dials his phone number.
I've been on other forums for the last 5 years. I was active on those, and did not feel the need to post on 2 - 3 forums at a time. I did read threads on this site though, and the trend in your case on every forum is clear. You are 100% on AI's nuts, and downplay EVERYTHING else.

I haven't seen any recent problems with Lloyd's stuff. I am aware some folks had problems with Lloyd's heads in the past. I don't believe it was a wide spread issue though, certainly not like the bad batch of beehives from Comp Cams, or the collapsing lifters also from Comp. Should people not use CC either?

If you could open your mind just a little, you may see that Lloyd has a following, because his stuff gets results. Guys running his stuff go toe to toe with AI, and faster. BigSmokey is running 6.7's with some LE2's and a small cam letting out before the stripe.. that's easy 10.5's. sweetbmxrider went 10.8's with LE2's and a decent hydraulic roller from Lloyd - the time was within hundredths of Joe's 450 rwhp 383 car. The list goes on..

You are always around to bash, but I noticed when a thread is started giving props to Lloyd you are nowhere to be found

Yes before you bring it up, I know AI has some of the fastest NA cars around. They are the natural choice when plopping down big money on a build. Keep your eyes open like I said.. there may be a contender here in the next year from the LE camp.
Old 12-15-2014, 12:06 PM
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With CNC you know what you get is identical.

With hand porting how can you be sure what you get is the same as the guy who managed to go fast?
Drop your vendor vs. vendor bull and answer that question.
Old 12-15-2014, 02:03 PM
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Originally Posted by 96capricemgr
With CNC you know what you get is identical.

With hand porting how can you be sure what you get is the same as the guy who managed to go fast?
Drop your vendor vs. vendor bull and answer that question.
Skilled hand porters have techniques for consistency. Here is an example.. the guy who has my motor does a lot of hand porting, and he is a little more obsessive than most about perfection. He measures how large he wants the port opening, uses a mill to machine a .030 step. He lines the intake up the same way.. when placed on the motor there is a perfect match.

I won't claim to have a lot of knowledge to what these guys do. The above example came up in conversation. I haven't picked his brain to much on the subject. I am more of a results over data points kind of guy.

Short answer is you will never have perfection every time. The meaningful question would be does it matter?
Old 12-15-2014, 02:17 PM
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I went the CNC'd route. Almost don't want to mention the porter out loud, it seems like there is a huge group of people in the LTx world who get automatically butt-hurt whenever Advanced Induction is mentioned in a positive or superlative light. I've never really understood why, myself and several personal friends have had LTx head work done by them and the goods have always performed either as expected, or better than expected.

When someone has a great head, writes a CNC program to duplicate it, uses well-maintained very high-end CNC equipment to do the cutting....the choice seemed pretty simple to me. With the CNC'd stuff, you KNOW you're getting the same quality work every time.

Does Lloyd do bad work? Not that I'm aware of. I've heard about the infrequent, isolated issue or two in the past, but overall I wouldn't try to talk anyone out of his stuff because for every negative thing I've heard, there have been literally hundreds of positives. I've participated in several builds that involved his stuff and they all turned out well. With the volume Lloyd seems to be doing, I'm not exactly sure why he hasn't gone the CNC route.

I personally went with AI for three reasons....that they are CNC'd, they have a great product, and their shop is local to me.

As far as DIY porting on LTx heads. I know that these heads do benefit from some very minor clean-up work and unshrouding the valves and other basic stuff, just like any other head. However, when someone goes in without quite a bit of knowledge and begins removing a significant amount of metal, I think they are risking doing more harm than good on a set of these heads. It's a big learning curve, just hogging out ports like folks did in the old says will not result in a good performing LT head.

Last edited by HellTeeOne; 12-15-2014 at 02:23 PM.
Old 12-15-2014, 05:21 PM
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Again PA94Z when buying hand ported how do you know you are getting the same product as the few exceptionally fast cars?

A hand porter might have had a good day, or know that customer will make them look good and put extra effort into their product. There are definitely vendors who put varying levels of effort into customers product depending on how well they expect the build to go, one tuner in particular is terrible about this and even his fast customers see how badly the "nobodies" cars are tuned compared to their own.

With CNC it would be a huge amount of extra work to give customers anything but exactly the same product.
There are hand porters who can keep things consistent, but when buying a "budget" head for a forgotten platform and only paying $1300 including springs and valves, machining, cleaning..........................

Again you are the one bringing up brands, you are the one trying to insult me, you are the one trying to emulate cardo.
Old 12-15-2014, 08:14 PM
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Agree with CNC probably being the most consistent or should be anyway

Someone who does them by hand and keeps on top of the QC will never ever be cheap; they cant pay the bills giving it away and will get paid for what they know. Others rush through them or farm them out ie mass production mentality;theres not much money in hand porting these days like there once was.
Most that pay for this stuff wouldnt know the difference of good from bad anyway a monkey can spend enough time with a roll and make something "look" good. Sometimes a proper job means not even touching a certain area(s) of the head, others rolling makes no difference. But people would go nuts and say they got ripped if it didnt all look pretty lol

Does anyone think one could sit with a grinder 8 hrs a day every day yr after yr? They wouldnt be able to hold a pen to write their name. lol
.
No porter is going to do stuff for peanuts then make sure they are perfectly consistent or within a small range, flow them etc etc (however if they are that good they really dont need to). It generally WONT HAPPEN unless youre cracking open your wallet. Flow benches cost money most charge about $50/hr, some $50 per port they cant give that away;perhaps the right person/situation...maybe

At the end of the day its really hard to compare
Track elevations, DA, tuning weight reduction/driving exper, fluffed up dyno/flow #s someone may not be aware of it all happens. So many variables the arguing is pointless

Be happy with what ya got and go have some fun.

Last edited by cuisinartvette; 12-15-2014 at 08:49 PM.
Old 12-15-2014, 08:15 PM
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Originally Posted by 96capricemgr
Again PA94Z when buying hand ported how do you know you are getting the same product as the few exceptionally fast cars?

A hand porter might have had a good day, or know that customer will make them look good and put extra effort into their product. There are definitely vendors who put varying levels of effort into customers product depending on how well they expect the build to go, one tuner in particular is terrible about this and even his fast customers see how badly the "nobodies" cars are tuned compared to their own.

With CNC it would be a huge amount of extra work to give customers anything but exactly the same product.
There are hand porters who can keep things consistent, but when buying a "budget" head for a forgotten platform and only paying $1300 including springs and valves, machining, cleaning..........................

Again you are the one bringing up brands, you are the one trying to insult me, you are the one trying to emulate cardo.
If you would have read my post you would see I answered your question. No hand porter will match a machine in consistency. Someone who takes pride in their work will make every effort to give a solid product every time, which I believe Lloyd does. Results are hard to argue with... You are desperately grasping at straws here.

All I see from you is assumptions, and accusations. Fact is you have never ran Lloyds stuff, and you don't know what you're talking about. On one hand you claim you aren't bashing a brand, then you say dumb **** like what I bolded in your post and act like it wasn't directed at anyone.. what a joke

For as many poor running LE setups, there are just as many poor running AI setups. If you want a leg to stand on in this, buy some LE heads and do your own testing. Or just keep talking like a fool and getting called out on it. I could care less either way. I'm done.
Old 12-15-2014, 09:42 PM
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Originally Posted by PA94Z
For as many poor running LE setups, there are just as many poor running AI setups. If you want a leg to stand on in this, buy some LE heads and do your own testing. Or just keep talking like a fool and getting called out on it. I could care less either way. I'm done.
Actually, speed_deamon did that very thing. He had an LE setup, which ultimately he got rid of because of poor performance and discovered several cracked valve guides. Went with AI and ran significantly quicker and faster. I am not brand loyal, just stating fact. And yes, it would appear even though facts are being presented to you regarding CNC vs. hand porting it is you who is trying to enable the situation with a bunch of emotional titty baby nonsense when no brand has been brought up.
Old 12-15-2014, 11:41 PM
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Originally Posted by SS RRR
Actually, speed_deamon did that very thing. He had an LE setup, which ultimately he got rid of because of poor performance and discovered several cracked valve guides. Went with AI and ran significantly quicker and faster. I am not brand loyal, just stating fact. And yes, it would appear even though facts are being presented to you regarding CNC vs. hand porting it is you who is trying to enable the situation with a bunch of emotional titty baby nonsense when no brand has been brought up.
I don't doubt situations come up where a switch made a big difference. That really has very little to do with a discussion on head porting. You may be misinterpreting what I suggested 96 do. Camshaft duration, lobe characteristics, accuracy in the grinding process, valve springs, and geometry are variables that can skew results. Not to mention the ability of the person to properly degree the cam on installation. In Speed Demons case he had oil leaking through the guides into the mixture as well, lowering fuel octane.

I am well aware of benefits to CNC work, I need no facts presented. If you go up to post 26 our resident AI banner man threw the first stone making a snide remark about "saving 300$ on a budget head".. let's not act dumb like we don't know who that was targeted at. For the record I have nothing bad to say about AI, they have a great product. I really like the cam kits, very complete with quality parts., and have recommended them to people in the past. Though for how much they charge they could hire someone to answer the phone.
Old 12-15-2014, 11:42 PM
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Originally Posted by cuisinartvette
Agree with CNC probably being the most consistent or should be anyway

Someone who does them by hand and keeps on top of the QC will never ever be cheap; they cant pay the bills giving it away and will get paid for what they know. Others rush through them or farm them out ie mass production mentality;theres not much money in hand porting these days like there once was.
Most that pay for this stuff wouldnt know the difference of good from bad anyway a monkey can spend enough time with a roll and make something "look" good. Sometimes a proper job means not even touching a certain area(s) of the head, others rolling makes no difference. But people would go nuts and say they got ripped if it didnt all look pretty lol

Does anyone think one could sit with a grinder 8 hrs a day every day yr after yr? They wouldnt be able to hold a pen to write their name. lol
.
No porter is going to do stuff for peanuts then make sure they are perfectly consistent or within a small range, flow them etc etc (however if they are that good they really dont need to). It generally WONT HAPPEN unless youre cracking open your wallet. Flow benches cost money most charge about $50/hr, some $50 per port they cant give that away;perhaps the right person/situation...maybe

At the end of the day its really hard to compare
Track elevations, DA, tuning weight reduction/driving exper, fluffed up dyno/flow #s someone may not be aware of it all happens. So many variables the arguing is pointless

Be happy with what ya got and go have some fun.
Thank you for the well informed post


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