Upgrading the A20

[Crazy_C]

I was hoping some guys on here could give me some pointers on upgrading my A20A4 engine. I was originally thinking about swapping a B18C4 in there, but to be honest, I can't be assed with the hassle of an engine swap LOL

I am looking to get the Bisimoto stage 2 cams, and use the intake manifold and fuel rail off the B16 or B18 (whichever is better to use) but I was hoping people could give me tips on which intake mani and fuel rail is better, if there's a better throttle body that I can use, and if there's an uprated dizzy for the A series engines.


Cheers

[RAZR]

Are you planning on going NA with your motor? are you going to build the motor? or leaving the internals stock? cause a stage 2 cam is kinda aggressive for a motor that prolly isnt gunna be built. (im just assuming your not going to buld the motor.

For performance I would go OBD-1 with that you have to swap the dizzy then youll be able to tune your engine. I dont have any expertise in the b16/b18 manifolds so i cant help you there.

I think you already know this but get a SRI, exhaust and upgrade igniton for more performance.

Hope that helps.

[Crazy_C]

I already have an SRI with a CAI type modification that feeds cold air to it when the headlamps are on sleepy mode. As for the exhaust, mine is non cat from standard, and I have the mid box where the cat would have been, and I have a cherry bomb mid box as a back box.

I will most probably be staying N/A with it, mainly because it's a daily driver, and I don't fancy the fuel costs for driving a turbo 60 miles a day with fuel over $10/gallon!!!!!!!!


Whichever way I did it, I'd look to rebuild the engine, just to make it nice and strong and healthy. I could go with a built motor if it would actually give any gains on a n/a build, but I would almost certainly stick to stock internals.

Ideally though I'd like to stay away from running computers. I would prefer a carb set up, but I have EFI so I'll keep with that but I don't want to be adding any ECUs or OBD systems if I can help it.

[AccordEpicenter]

I already have an SRI with a CAI type modification that feeds cold air to it when the headlamps are on sleepy mode. As for the exhaust, mine is non cat from standard, and I have the mid box where the cat would have been, and I have a cherry bomb mid box as a back box.

I will most probably be staying N/A with it, mainly because it's a daily driver, and I don't fancy the fuel costs for driving a turbo 60 miles a day with fuel over $10/gallon!!!!!!!!


Whichever way I did it, I'd look to rebuild the engine, just to make it nice and strong and healthy. I could go with a built motor if it would actually give any gains on a n/a build, but I would almost certainly stick to stock internals.

Ideally though I'd like to stay away from running computers. I would prefer a carb set up, but I have EFI so I'll keep with that but I don't want to be adding any ECUs or OBD systems if I can help it.

Just a thought, but if you have a big enough turbo and keep your foot out of it and have the setup tuned properly theres no reason you shouldnt get as good if not better mileage than NA. It depends on how much you thrash it if everything is set up correctly. True story

[gfrg88]

He's right. People are so afraid of having a Turbo DD. Just stay out of boost.

But if you wanna stay NA, and not deal with computers, swap an a18 head on. Stage 2 cam, Weber's, obx heade, 2.5 exhaust and be done.

[cygnus x-1]

Whichever way I did it, I'd look to rebuild the engine, just to make it nice and strong and healthy. I could go with a built motor if it would actually give any gains on a n/a build, but I would almost certainly stick to stock internals.

A stock bottom end is fine until you start getting close to 200HP, which you aren't going to do NA without serious effort.

Ideally though I'd like to stay away from running computers. I would prefer a carb set up, but I have EFI so I'll keep with that but I don't want to be adding any ECUs or OBD systems if I can help it.

Problem is you can't really tune the stock computer so you're not making the best use of any modifications.

You could convert to carb without too much trouble. It would make many of the sensors useless but it would give you the ability to tune. You would need to plumb in a low pressure bypass style regulator to use the existing fuel pump, or switch to a carb fuel pump.

I am looking to get the Bisimoto stage 2 cams,

A stage 2 cam may be a little much, especially with the stock ECU. A stage 2 raises the power band quite a bit, which is not always a good thing. I would stick with a stage 1.

and use the intake manifold and fuel rail off the B16 or B18 (whichever is better to use) but I was hoping people could give me tips on which intake mani and fuel rail is better, if there's a better throttle body that I can use,

The B18 intake is tuned for lower RPMs than the B16, so it's probably a better choice if you want to stick to a close to stock power band. The B16 intake would be a better match to a stage 2 cam, but then of course you don't have a way to tune the fuel so .... back to where we started.

and if there's an uprated dizzy for the A series engines.

There is not. And honestly the stock distributor is fine, unless you want to be able to tune it or it's worn out. This is where you decide if you want to stick with fuel injection or go to carbs. If stick with fuel injection, then you convert to OBD1 and get an ECU (and distributor) that controls fuel and timing. End of story. If go to carbs, then you do a Megajolt Lite conversion and have fully tunable electronic ignition. (No more parts to wear out. Yay!)

He's right. People are so afraid of having a Turbo DD. Just stay out of boost.

Well, yes that's true. But isn't that like hiring a hooker just to hang around and watch Netflix with you?

But if you wanna stay NA, and not deal with computers, swap an a18 head on. Stage 2 cam, Weber's, obx heade, 2.5 exhaust and be done.

A decent plan. Although A18 heads are getting hard to come by and Weber manifolds for them even more rare. If you want dual Webers it's far easier to just get a manifold from Rowland and bolt everything up to the A20 head. Have the head milled down 1mm to bump up compression a bit. Do a little gasket matching and you're done.

OR, if you don't need that much carb get a carbed A20 manifold and put a Weber 38/38 on it. Super easy to tune and less expensive than a dual Weber (DCOE) setup. This a perfect match for a stage 1 cam.


C|

[lostforawhile]

hey cygnus where is the thread on the megajolt setup, I will probably stick with my stock dizzy with the msd setup, but I was wanting to read it

[cygnus x-1]

hey cygnus where is the thread on the megajolt setup, I will probably stick with my stock dizzy with the msd setup, but I was wanting to read it

I don't think there is a main thread but a top level search for "Megajolt" pulls up the relevant threads and not too many others.

With your fab skills you could put together a setup for well under $200. Although your setup might be a little different with that extra alternator you have.

C|

[Crazy_C]

I have no fear of a turbo DD, I've had plenty of them in the past, but I drive 60 miles a day, 5 days a week for work, currently spending about $100 a week on fuel!! Last thing I want is to make that any more expensive!!


With doing a carb conversion, can I just use the intake manifold from a carb'd A20 from an '86 Accord? I ask as a mate of mine has 2 Aerodecks, one FI, one carb'd, both A20 engines.

What is the best carb set up by the way? Would it be individual bike carbs, or something like a twin Weber set up?


I will probably see about doing a turbo'd carb build on the engine then. I might see if I can buy my mate's entire carb'd engine, to build that up over a period of time till it's ready to drop in



Good to know about the Megajolt system though too, cheers for the tip on that one.

[lostforawhile]

I have no fear of a turbo DD, I've had plenty of them in the past, but I drive 60 miles a day, 5 days a week for work, currently spending about $100 a week on fuel!! Last thing I want is to make that any more expensive!!


With doing a carb conversion, can I just use the intake manifold from a carb'd A20 from an '86 Accord? I ask as a mate of mine has 2 Aerodecks, one FI, one carb'd, both A20 engines.

What is the best carb set up by the way? Would it be individual bike carbs, or something like a twin Weber set up?


I will probably see about doing a turbo'd carb build on the engine then. I might see if I can buy my mate's entire carb'd engine, to build that up over a period of time till it's ready to drop in



Good to know about the Megajolt system though too, cheers for the tip on that one.

best setup would be the dual SU's like i've got, but I don't think you want to deal with that conversion, if you have an A20 manifold, it can be adapted to fit the single webber, if you are in a hurry thats the best setup and there's a lot of info on it here on the site

[Crazy_C]

Time is not an issue to me, and I have access to facilities to build custom parts.

I have friends who have a garage, and they have built a conversion intake to allow a Ford CVH to run on individual bike carbs, so doing a dual carb conversion wouldn't really be a big issue.



Main thing is though, an A20 carb mani will fit in replacement of the PGM-FI system on a later A20, yes?

[lostforawhile]

Time is not an issue to me, and I have access to facilities to build custom parts.

I have friends who have a garage, and they have built a conversion intake to allow a Ford CVH to run on individual bike carbs, so doing a dual carb conversion wouldn't really be a big issue.



Main thing is though, an A20 carb mani will fit in replacement of the PGM-FI system on a later A20, yes?

yea it will bolt right up there isn't really any difference other then the cam, the block is also the same

[cygnus x-1]

With doing a carb conversion, can I just use the intake manifold from a carb'd A20 from an '86 Accord? I ask as a mate of mine has 2 Aerodecks, one FI, one carb'd, both A20 engines.

Yes. For this option you would use a Weber 32/36 or 38/38 (both are 2bbl down draft carbs). I would pick the 38/38 because it will have more performance potential and it's a little easier to tune.

What is the best carb set up by the way? Would it be individual bike carbs, or something like a twin Weber set up?

Either really if you want a side draft setup. Twin Webers (DCOE) is a little more conventional and there is an off the shelf manifold for it.

http://www.manifolds.co.za/index.php...id=42&Itemid=2

This will likely hurt the mileage a bit since it's more difficult to run vacuum advance with individual runner carbs. The best option for ignition then is the Megajolt conversion with the advance running off throttle position instead of vacuum. The stock distributor doesn't really like the lumpy vacuum signal from a twin Weber setup.

I will probably see about doing a turbo'd carb build on the engine then. I might see if I can buy my mate's entire carb'd engine, to build that up over a period of time till it's ready to drop in

I would recommend against this unless you really know what you're doing.

Good to know about the Megajolt system though too, cheers for the tip on that one.

Yeah, it's a nice system for carbed engines. Especially when there aren't any aftermarket distributors available.


C|

[Crazy_C]

I would recommend against this unless you really know what you're doing.

Yea, this isn't an issue, as my mates run their own garage where they can make an ITB set up quite easily (something that I may do at a later stage using bike carbs), and they do engine conversions, builds, and all sorts, so a turbo carb build won't be any issue. I also have a friend with another garage who has a B16A powered Lotus Elise with a turbo'd carb set up on it.

I'll still start off with the carb conversion and the stage 2 cams and see how that goes, and then see about using parts off a Metro turbo and see about giving it some boost

[rjudgey]

What about using two bike carbs like A18 but better ones or a single Weber DCOE 50 will give you good performance versus fuel? Just get your mates to rig up a new inlet to suit and your golden! BTW you can tune twin webbers to be reasonably fuel efficient it's just most go for max power rather than mpg! Lighter you can make the car the better performance and mpg you'll get. My 200bhp twin webered car with the taller gearbox in can do 400 miles to a full tank on the highway which I think isn't too shabby! lol!

[cygnus x-1]

What about using two bike carbs like A18 but better ones or a single Weber DCOE 50 will give you good performance versus fuel? Just get your mates to rig up a new inlet to suit and your golden!

I had that same thought too. Take a standard A20 carb manifold, chop off the back half and weld on a flange for a single Weber side draught (look I spelled it right!). This would be very similar to how Lostforawhile did his SU conversion.

C|

[lostforawhile]

I had that same thought too. Take a standard A20 carb manifold, chop off the back half and weld on a flange for a single Weber side draught (look I spelled it right!). This would be very similar to how Lostforawhile did his SU conversion.

C|

I actually have a plate tigged on to the four runners on mine and then the datsun manifold bolts to it. the ports are machined into the plate. don't forget if you use the A20 manifold, you have to angle whatever you weld to it, the engine is tilted forward

[88lxi-shortram]

just out of curiousity what advantages would you get from a a18 head. i always figured that you want a head from a a20 for more flow. it seems an a18 head would have less flow

[cygnus x-1]

just out of curiousity what advantages would you get from a a18 head. i always figured that you want a head from a a20 for more flow. it seems an a18 head would have less flow

The chambers are smaller so you get a little higher compression. IMO it's not worth it though since A18 heads are hard to find and there are virtually no options for intake manifolds.

C|

[Crazy_C]

Well it looks like things are coming together for this plan. I have bought a stage one Colt cam with a Golden Eagle adjustable pulley from Epic1400cs, and I am waiting on my mate to take the carb set up off his DX for me to have. Then need to see about getting the Weber 38 to stick on there, and then I'll have fun and enjoy

I have thought about a bike carb set up, and it may happen in a while, but I'll stick with the Weber 38 for the time being, just wanna get it all set up and running first y'know?

[cygnus x-1]

Well it looks like things are coming together for this plan. I have bought a stage one Colt cam with a Golden Eagle adjustable pulley from Epic1400cs, and I am waiting on my mate to take the carb set up off his DX for me to have. Then need to see about getting the Weber 38 to stick on there, and then I'll have fun and enjoy

I have thought about a bike carb set up, and it may happen in a while, but I'll stick with the Weber 38 for the time being, just wanna get it all set up and running first y'know?

The Weber 38 is a great carb; very easy to tune. I know you'll be happy.

The easiest way to fit that carb is to get the adapter plate for the 32/36 (same bolt pattern). But if you fancy a little custom work you might consider trying to fill the existing manifold bolt holes and drill/tap new holes to fit the new carb directly. It eliminates two gaskets and gets you more hood clearance for the air cleaner.

C|