420a Head Stage 4 Question

[inferno617]

The other day I tried posting in the newbie forum since I'm limited and I'm not sure if anyone even goes in there. I posted a question the other day and got no response. Is there someone on here that i can PM or that can help me find out what I need to do to my head to make it a stage 4? I know it needs porting and the whole shebang. I am interested in getting the specs that I can give to my my local machine shop. I hope to get the specifications to the shop by the beginning of next week, so i can order up parts.

 

[all_motor_mike]

The other day I tried posting in the newbie forum since I'm limited and I'm not sure if anyone even goes in there. I posted a question the other day and got no response. Is there someone on here that i can PM or that can help me find out what I need to do to my head to make it a stage 4? I know it needs porting and the whole shebang. I am interested in getting the specs that I can give to my my local machine shop. I hope to get the specifications to the shop by the beginning of next week, so i can order up parts.

stage 4........ no no no u want a stage 12

its clear that u have no idea what your talking about here. where did u get "stage 4" from first of all? howells website?

"stage 1,2,3,4"........ "street","street/strip", "race".......... "dominator I, II, III, etc".............. every company calls there head "packages" different things. and im sure all of them are for the most part different in terms of whats being done with few similarities. the person whos work u want your machine shop to try and copy, should be the person u need to ask whats done to their stage 4 head. or better yet u could send it to that person and have them do it because if the compay or person is reputablwe then u know they know what they are doing. and on a side note........ if u need to tell your machine shop what to do to the head when u your self dont know then they shouldnt be hacking on it either. just a little FYI sir.


mike

 

[knight007]

i was under the impression that the 420a heads flowed fine as is?

 

[LD25Delta9]

i was under the impression that the 420a heads flowed fine as is?

They do. They were designed by Lotus Engineers. However, there isn't a head that can't benefit from a good port and polish.

to the OP: If you want a head, get an Indy Head. And like All_motor_mike said, if you have to give specs to your local machine shop, I wouldn't have them do the work. Our heads are finicky with the head to block clearances and if they screw that up by 1/64" you'll skip a tooth and KABOOM! DO YOUR RESEARCH!!!! I can't tell you how many hours I've spent reading these forums and 2gnt's forums learning and soaking in knowledge, at least 200 in all seriousness. And I'm still just a newbie. READ READ READ!

 

[rstchris]

Bring them some intake and exhaust gaskets and tell them to match them and throw some valve springs in so you could put cams in. Oh, don't forget a good cleaning and surface job.

 

[inferno617]

I was on concept illusions site and they have stage 1-4, 4 being for race with +1mm over valves and fully upgraded springs. Stage 12 sounds ridiculous and would kill my car. I want to go with a stage 3 porting and 5 angle valve job but have nothing to go off of, for as far as I can port. Taking too much off is bad and can weaken the water jackets, So i want to get close but not too close. I'm looking at using my obx manifold and turbo boosted between 15psi and 30psi. I want the max air flow that i can get for my money

 

[VelocitàPaola]

I was on concept illusions site and they have stage 1-4, 4 being for race with +1mm over valves and fully upgraded springs. Stage 12 sounds ridiculous and would kill my car. I want to go with a stage 3 porting and 5 angle valve job but have nothing to go off of, for as far as I can port. Taking too much off is bad and can weaken the water jackets, So i want to get close but not too close. I'm looking at using my obx manifold and turbo boosted between 15psi and 30psi. I want the max air flow that i can get for my money

He was being facetious and pointing out the absurdity of labels such as "stage 4." Those labels are meaningless. Take your head to a reputable machine shop that uses a flow bench. If they know what they're doing, you shouldn't have to provide them with any specifications other than your goals for the car.

 

[all_motor_mike]

Bring them some intake and exhaust gaskets and tell them to match them.

i love how everyone gives this advice when somebody asks about porting. this is not good advice (in the case of the exhaust port) for a few reasons. and these are them......... if your exhaust gasket is bigger then your ports by a big margin (this is definitely the case with a few of the 4g63's aftermarket gaskets) then u may be making your port bigger then the damn exhaust manifold, header, turbo manifold whatever your running. thats gonna cause alot of turbulance and make u end up losing power. another reason is in the event that the port ends up matching the exhaust manifold then your not going to have any provision for anti reversion. now if yourrunning big cams on an all motor setup and have a bit of over lap then your not going to get optimum scavenging in which case u can also lose power. dont gasket match the exhaust ports unless u know about the things mentioned above. and dont touch the floor on the outlet of the 420a exhaust port.......... u dont want to lower it any more than it already is. u know, u should just send your head to me.


mike

 

[inferno617]

Ok so if i just match to my intake which i'm not sure if the OBX is stock size or not. what is the maximum I can go and what if the stock oe size?

 

[dsmmitsubishi]

sloyboy racing sells a head all done with ported and polished,5 angle valves croer valve springs etc etc for 1499.00 that prob ## best bet if u get it done and buy all that shit u prob spend just as much

 

[all_motor_mike]

Ok so if i just match to my intake which i'm not sure if the OBX is stock size or not. what is the maximum I can go and what if the stock oe size?

what are your goals for the car? how much power do you want to make or what do you want it to run in the 1/4 mile (if you drag race that is). and how much are you wanting to spend on the head work?


mike

 

[inferno617]

I'd perfer to not spend more then 1000 right now and all those head do not come with lifters rockers and so on. I plan to have over 400 i wish 500 and I would like to run low 11s. I can get all parts for the head for wholesale prices which helps alot to keep it cheap.

 

[NeMiZiS]

I'd perfer to not spend more then 1000 right now and all those head do not come with lifters rockers and so on. I plan to have over 400 i wish 500 and I would like to run low 11s. I can get all parts for the head for wholesale prices which helps alot to keep it cheap.

Low 11's on an all motor 420A?.
Well it sounds nice.

 

[99BoostedRS]

the most you can probably get from a 420a motor is high 13's and that would need alot work too.

 

[GsXdSmKingGsX]

I'd perfer to not spend more then 1000 right now and all those head do not come with lifters rockers and so on. I plan to have over 400 i wish 500 and I would like to run low 11s. I can get all parts for the head for wholesale prices which helps alot to keep it cheap.

Low 11's??? WTF

Good luck buddy.

 

[rstchris]

I just like to think that most people are not retards and gonna take an angle grinder to the head. If you are spending time and money on porting a head and leaving the mani's stock then you fall into that category. So, within reason, match the head and mani's without exagerating. In the case of the 420a, the exhaust gaskets are pretty close so yeah, he would be fine matching them.

 

[all_motor_mike]

I just like to think that most people are not retards and gonna take an angle grinder to the head. If you are spending time and money on porting a head and leaving the mani's stock then you fall into that category. So, within reason, match the head and mani's without exagerating. In the case of the 420a, the exhaust gaskets are pretty close so yeah, he would be fine matching them.

if u gasket match the head (exhaust side) and exhaust manifold then there will be no provision to stop reversion like i mentioned above.


mike

 

[inferno617]

I plan to do a lot of work to the car with full power upgrades. if the project doesn't go as planned. I will grab another 2gen and strip it of everything and fabricate it to fit my 454. I know its a lot of work but it would be worth it. Ass wheel drive eclipse.