9 replies to this topic

[radrice86]

Hello! I'm miserably new to this forum and something less than a mechanical genius; please bear with my noob-ist tendencies...

I am building a motor to throw into my 3g '86 DX. I will be purchasing a used motor shortly, and I'm curious as to which set-up will be most ideal for this project: my goal is to get maximum, reasonably-attainable power from a carbureted set-up, without going custom-everything...

Should I put a fuel-injected 3g SI head onto the carb'd DX bottom end? Or will I be better off just rebuilding an entire SI motor?

What pistons will work best/attain highest compression with stock valves?

And finally (dreading the answer to this one): where can I acquire the appropriate intake manifold(s) for dual Weber/or Mikuni 40's? I have been told "good luck" finding these, with loads of punctuated lack-of-faith. Custom-welding/fabrication of these is an option, but finding a set would make this project loads simpler...

--Thank you! I have found the information on this forum to be immensely valuable (true Guru's on here!), and I'll be sharing my progress soon as this project gets underway...

[Aren D.]

Because you are going to stick with the ew or d15a3 type motor the best way to make power will be high rpm and high compression.

For the si head you can do a cheap spring upgrade to support higher rpms.
The DX used a single stiffer spring for its valves and the si uses 2 springs an inner and an outer. If you put the DX springs as the si outer then you will hive a good set up for staying above 7000rpms.

the si has higher compression and stronger rods but its the same block as long as you dont use a ew1 or 1300 motor its a 1.3 and not much fun

you can put in d16a1 pistions and bore out your ew3/d15a3 motor. I can not rember what compression will be but its high. around 11:1 or something. The 86/87 d16a1 pistions will have a lower cr then the 88/89.

Intake manifolds are no longer for sale, you need to find a used one, BUT I am moving to denver and happen to have a ew3 intake manifold and some 40 dcoe's and some 87 d16a1 pistons(but you can get new ones for 80.00)... I will be moving june 25ish!

[radrice86]

Excellent advice an knowledge- thank you Aren! And I will pm you regarding that sale...

Will the D16A1 pistons clear the stock valve setup?

[rexsk8er]

any time you build a motor check all clearances, especailly if you install other than stock parts.


Simply get some playdough or clay and put on the piston @ TDC than bold the head on and rotate the cams. You can measure the clearance from there


Also remember check other clearances with plasti-gauge and a caliper.


As far as the motor goes TWM sold out there carb IM division to Pierce Manifolds


http://www.pierceman...tCode=99003.705



Not sure if its truly available but they have it for sale on the web

[Maine_Honda_Racer]

The d16 pistons will clear the stock valves yes.

[radrice86]

Great advice- thanks to everyone! I appreciate the link for those manifolds if I cannot obtain a used one. Glad to know someone out there is making them!

[jsgprod]

Great advice- thanks to everyone! I appreciate the link for those manifolds if I cannot obtain a used one. Glad to know someone out there is making them!

I thought you were interested in Aren D's sidedrafts.

I was going to mention the other day that I have a TWM dual sidedraft manifold for the EW that I'll probably never use again. I even had it working on a CVCC head for a while when I first got them. The carbs have been sold however.

Jay

[blacksheep]

i got my manifold from pierce...it has a TWM stamp on it though...i think they use the original cast...mine was instock when i purchased and shipped from cali to nc in 5 or 6 days...the cast is good quality and plenty of material to bore away at for trick airflow grinds...also i went straight to an 86 Si motor...the cam is far better than whats in the carbed motors...otherwise Web Cams has one for around $365 plus your cam...one of the racer guys on here...gimme a bit and i'll remember who...sells .040 oversize pistons for both the carbed and Si motors...$200 and $240 respectively with new rings and wrist pins if i remember right...he also carries just about every performance part specific to the 3g

Edited by blacksheep, 09 June 2010 - 10:48 PM.

[radrice86]

Jsgprod: Thank you! It's looking like I've got a deal with Aren for the complete package; I was not 100% clear at first, but he's definitely got what I'm looking for...

Blacksheep: Do you happen to know if the Web Cam has a hotter grind than the stock SI? Or is it a factory replacement? As far as the pistons go, a bump to 11:1 or-near-it compression would be quite nice... I'd like to shoot for it as long as I can keep the motor-work/re-boring relatively reasonable cost-wise. If that gentleman's name comes to you, it may be of great help..!

Again, I do not have enough praise and thanks for everyone on this forum for their help and advice-- THANK YOU! Soon, my '86 DX will become a true Red Pepper, and I can't wait!

[Maine_Honda_Racer]

Hey blacksheep, think you could post your jetting sizes? My car seems to run a bit rich, I know it needs ot be leaned out some.