420a Head Work Question...

[terminal206]

Hi everyone,

I am new here and have researched, but can't find the answer that I need. I am currently rebuilding my 420a out of my 96 RS and was wondering what kind of head work I need done? I am trying to get quite a bit of horsepower out of the engine, and will be upgrading to all forged internals and making the motor a stroker, as well as turbo charging it. I was also thinking of adding nitrous to the car, but I'm not really sure about that yet.

Basically I want the fastest car I can get out of this without totally sacrificing the streetability of the car. The local machine shop has lots of experience with engine work, and I know the guy personally so I know he will do a good job, but there is one major problem. While the man has a lot of experience, I am in a small town in Tennessee, so basically everyone around me believes if it doesn't have eight cylinders it isn't fast. With that being said, the local shop has basically never dealt with imports. He doesn't know what needs to be done/what is safe to do, but if you ask him about a V8 he can tell you basically anything. As I said, he is good at machine work, but I have to know what to tell him to do, because if I don't he might ruin my head. I was wondering what would be good for my car with the upgrades that I listed above? If more information is needed just let me know, I will try to get it ASAP.

Any help is very appreciated!

 

[BigRand]

There really isn't too much to do the head. thats differetnt than any other car.

A good port polish job, a 3 or 5angle valve grind, and maybe some knife edging here or there.

its the bottom end where you want to pay attention for your turbo and or nitrous oxide application your going want to lower the compression for tune ability. More importantly is your fuel delivery...do your research and figure out which way you want to go on that.

 

[Locke]

Import or not, it's still a 4-stroke piston engine, and all the same rules apply. He can do anything he would do to a V8 to your straight 4. Although.....

On a big torquey V8, you can shift the powerband far north and still have enough leftover bottom end grunt to still be streetable. On our tiny little 4cyl motors, you can only move the powerband so far before it barely idles. We just dont have enough low end torque.

Big sticks and huge ports and valves will give you alot of power, but at the expense of bottom end. Turbo's alleviate this problem, as you can still have natural grunt down south, and boost for top end (as is the nature).

To use as a daily driver, I would keep the headwork minor. Halving the guides, and only gently opening the ports. A 3-angle job is always good, though not likely to yeild large improvements.

When you talk your machinist, just remind him you dont have alot of bottom end to sacrifice.

Good luck.

 

[Locke]

Beat me to it, Randy.

 

[terminal206]

Thanks guys, I really appreciate the help! Is this what you had done to your cars, if so did it help much? I was looking at the heads on Slowboy racing, and it seems like they have a lot done to them... I was thinking of going with something along the lines of this:

http://www.slowboyracing.com/more.php?id=3936&

or would this be better

http://www.slowboyracing.com/more.php?id=2489&

Do you think either of those would be okay, or would they be too much? This isn't a daily driver, I have an F150, 240sx, and Camaro also, but I would like it to be able to be a daily driver if I wanted it to be.

 

[Blitzeclips]

Make sure he uses a flow bench.

EDIT: On a personal note, it's hard to place credit/recognition/respect on services from people you have NEVER done business with. WHat may seem like a GREAT port job to one guy, may seem like CRAP to the next guy.

Walking in on my port guy/machinists shop proved enough for me. He was working on 2 12 cylinder (late 80's) Ferarri heads for a superior race team. I meen w-o-r-k-i-n-g. Ever seen one of those? Holy hell... it's almost as big as our blocks. I couldn't even begin to count the valves he was seating... Even after I chatted with him, I could tell he was passionate about his work, and even took it personally to some extent. This showed me he actually cared more then most machinists you find these days. Describe your daily driving style. City or rural? There are variables to account for when maintaining street/daily driving. I flat out said I'm shooting for very high numbers and times, yet need the port tamed enough for daily driving.

 

[terminal206]

What exactly is that? I must be really dumb when it comes to machine work...

 

[terminal206]

I know this guy very well, my dad owns a diesel shop and we get all our machine work done through him, so he will want to do a good job so we are happy with him to keep the amount of work we send him. He did the work on my Camaro and it runs just like it should, so I'm pretty sure I can trust him when it comes to doing it right.

 

[BigRand]

Just a side note....if you want this to be your daily driver but want big power...its gonna be your fuel system that determines how well that works in my opinion.

If I were you I would take a look at www.hahnracecraft.com and look into the porterfueler system they have that allows you to drive under normal fuel setup out of boost and a uses an extra 8 injectors for the in boost applications.

The reason I'm mentioning this is because your going to see more power gains from fuel and tuning than you would from machine work, Lotus designed our heads pretty well and there isn't that much more to get out of them.

 

[dr1665]

EDIT: On a personal note, it's hard to place credit/recognition/respect on services from people you have NEVER done business with. WHat may seem like a GREAT port job to one guy, may seem like CRAP to the next guy.

Walking in on my port guy/machinists shop proved enough for me. He was working on 2 12 cylinder (late 80's) Ferarri heads for a superior race team. I meen w-o-r-k-i-n-g. Ever seen one of those? Holy hell... it's almost as big as our blocks. I couldn't even begin to count the valves he was seating... Even after I chatted with him, I could tell he was passionate about his work, and even took it personally to some extent. This showed me he actually cared more then most machinists you find these days. Describe your daily driving style. City or rural? There are variables to account for when maintaining street/daily driving. I flat out said I'm shooting for very high numbers and times, yet need the port tamed enough for daily driving.

Who are you and what have you done with Blitz? WTF

This has to be the most nicely-done post I have ever seen from you. Sentence structure is good. Spelling and grammar are getting right up there. I tell you, man, you keep posting like this and avoid drama, and you're on your way. Good show...

...and good information. You allude to the level of his experience with mention of just what engines on which he was working and finding a vendor who is equally passionate about what he does - going beyond just enjoying working on cars. If you can find someone with experience who sees what he does as art (and not some Jackson Pollack stuff, but smooth, flowing art), then you are golden.

For the OP, any engine machinist who ports heads on V8s should be able to do anything you need. Eddy Fierro ported my head and, when I needed to have a cam-retainer-cap bolt removed and coiled, the V8 shop that put my bottom end together was quick to ask me who did my porting. He told me he saw all kinds of things that were done wrong and I should have had him do the work. I asked him what, specifically, he saw that was wrong and he came back with, "Well, we'd have to put it on the flowbench first." In other words, he knows what he's doing, but has his own style. (Also meaning he didn't see shit. Eddy's work is top shelf.)

Just be sure to remind your machinist that you aren't going to have a lot of bottom end torque, so you don't want things too aggressive. However, if you want the most power, you're going to have to sacrifice bottom end...

 

[bullettdsm]

Who are you and what have you done with Blitz? WTF

!


And as Driggs said, you're proabaly gonna lose that low end driveability (especially with low comp turbo pistons). I'm OK with it but some aren't.

MB

 

[newdsmtnr96]

I work at Harry Heads Machine Shop. There are Three Types of Port Jobs. Bowl Port= The exhaust and intake Bowl get ported and a gasket match. street port= full bowl port and exhaust Cleaned and ported, The full port and polish= intake bowls, runners,Gasket match, guide boss cleaned and shaved. I Personaly Gained 80 cfm. Aprox cost would be around 620.00. But you do recive a Before and after flow sheet. That price maybe a little high. But we are professional's and do it right. If any one would like here is the number


(712) 277-2911

 

[dr1665]

I work at Harry Heads Machine Shop. There are Three Types of Port Jobs. Bowl Port= The exhaust and intake Bowl get ported and a gasket match. street port= full bowl port and exhaust Cleaned and ported, The full port and polish= intake bowls, runners,Gasket match, guide boss cleaned and shaved. I Personaly Gained 80 cfm. Aprox cost would be around 620.00. But you do recive a Before and after flow sheet. That price maybe a little high. But we are professional's and do it right. If any one would like here is the number


(712) 277-2911

How can you have this much experience with engine building (especially air/fuel delivery theory) and yet be so clueless in that injector thread? Please explain. It's kinda shady.

EDIT:
Not to be rude or anything, but I would suspect that someone who does headwork for a living would have a solid grasp on just how much fuel and engine could burn, given the increases in airflow their portwork provided. If you've got Xci displacement stock and you know you want something near stoich as far as AFR and you know how much air your head flows, I would think you could figure out how much fuel you need better than most people.

Just saying...

 

[Blitzeclips]

I work at Harry Heads Machine Shop. There are Three Types of Port Jobs. Bowl Port= The exhaust and intake Bowl get ported and a gasket match. street port= full bowl port and exhaust Cleaned and ported, The full port and polish= intake bowls, runners,Gasket match, guide boss cleaned and shaved. I Personaly Gained 80 cfm. Aprox cost would be around 620.00. But you do recive a Before and after flow sheet. That price maybe a little high. But we are professional's and do it right. If any one would like here is the number


(712) 277-2911

The price sounds about right. I had the full port done to my head and was charged about $750. I needed the valve seats bored for my oversized vavles, he also bolted the head on and cams down for me. Set the timing, etc. So I'd say I got a deal. It's alot of money, but like I always say: If you're going to do it, do it right. Professional is the route.

 

[newdsmtnr96]

Just letting you know... the boss he tought me how to do head work.. i dont know much about dsm stuff. or even Motor things.. but i know what the mechanic book says and i do things from there i have a haynes and a cheltons book i read.. but I work full time learning and doing port work.. i been working there for a while and now Understand and now can do professional port work...
This help?
new dsmtuner

 

[newdsmtnr96]

oh ya and to save your self some money ...Polish isnt really helping any thing but to make it pretty : )