ES3 vs A18 & BT

[phrenology]

Here is a quick question for all of you who know something about G2s. I've been reading posts here and there but haven't been able to figue this out. I know that the ES, ET, and EK series motors from the Prelude first gens and Accord 2Gs were all 12 valve CVCC heads, but was the ES3 from the 85 Se-i Accord or the dual sidedraft A18/BT from the 87 Prelude non-CVCC?

[PhydeauX]

The ET (mid 2g prelude dual carb) is not a cvcc engine, its pretty much the same as the a18 (late 2g prelude dual carb). The ES1 (early 2g prelude dual carb) and ES2 (late 2g accord) are cvcc engines. The EK(early 2g accrod and 1g prelude) is cvcc too but from a diferent faminly and not going to fit an 84-85. I don't know if the ES3 is cvcc or not. I've run across a few of them and never bothered to look. Use a BS, BT, or A20. They are all 2.0l as opposed to 1.8 and there's no replacement for displacement to use the old cliché. The motors all cost about the same and one is just as easy to swap as the other so there is really no reason not to go with the bigger motor.

andy

[phrenology]

The ET (mid 2g prelude dual carb) is not a cvcc engine, its pretty much the same as the a18 (late 2g prelude dual carb). The ES1 (early 2g prelude dual carb) and ES2 (late 2g accord) are cvcc engines. The EK(early 2g accrod and 1g prelude) is cvcc too but from a diferent faminly and not going to fit an 84-85. I don't know if the ES3 is cvcc or not. I've run across a few of them and never bothered to look. Use a BS, BT, or A20. They are all 2.0l as opposed to 1.8 and there's no replacement for displacement to use the old cliché. The motors all cost about the same and one is just as easy to swap as the other so there is really no reason not to go with the bigger motor.

andy

Thanks for the clearification. BTW I meant A18/ET2 not BT sorry. I have done a bit of homework on these engines and the reason I ask is because there is alot going around about high compression benefits of A20 block/A18 head combos. I have two A20s and two ES2s. I know EK and ES series are Cvcc. There was an immaculate 85 Se-i at the junkyard last month. We got the near mint (Accord god blessing) leather interior, dismissed the ES3 engine and its EFI components because we are through with CVCC engines (not knowing for fact if ES3 was Cvcc). When I went yesterday the Se-i had dissapeared completely! [Side note: the 85 SE-i does not have rear discs if you did not know]. I got the valve cover off an 87 (dual carbed non-SI) Lude at the junk yard to cover my second A20 head but didn't look into what the engine was. I later found out that it was an A18 dual carbed and not the mysterious B20A3 SOHC from the later dual carbed ludes. When I went back to look for the lude that I got the valve cover off of to get the A18 head. I found the only Prelude with the same description/year I found before was in fact CVCC. It's all a moot point because I have two rebuilt A20 heads for my A20A3 swap application. I was just wondering if the benefits of an A18head/A20 block frank are worth the trouble of finding one, getting it machined/rebuilt and getting a custom head gasket to match the two.

[PhydeauX]

85 SE-i's may not have rear disks but just about all 2g ludes do, and they pretty much bolt right on. You only need to lengthen the adjusting rod on the ebrake handel about an inch so the prelude ebrake cables fit and monkey a little with the brake lines to get the lude proportioning valve in to make it all work.

The mysterious dual carb b20a3 is found in 3g ludes only.

I'm sure sean and rjudgey can make good points on why each head is better then the other. You should be able to find that discussion on this board somewhere if you look hard enough. (I forget where it all took place). The a18 head will need a little bit of machining (combustion chambers need to be opened up to match the head gasket of an a20) to work.

andy

[rjudgey]

Well you could allways just use the original head and run A20 pistons on it if you use a felpro head gasket that will give you the big bore to be able to run an ET/ES/ET1/ES3/ES1/ES2 to 2.0litre spec, that will naturally raise your CR ratio as the piston size has increased. As for A18/A20 combo i have this in at the moment and it makes for quite a nice setup but the CR ratio is very low on mine as if you leave the chambers as they are the CR ratio is so high that detonation is a major problem, as well as blowing out head gaskets between cylinders and waterways. Your not going to gain huge amounts of BHP from just High CR ratios, getting more flow through the head is going to be more benefitial as you increase the static CR ratio, and also adding more air and fuel is allways going to result in a bigger bang and hence more power!! And in that respect the A18 head is poorer as the air and fuel has a tortured path to the chambers, with twin webers this is a little better but not hugely i'am only using this as an experiment head for my big valve conversion and also because it was the only inlet manifold i had for twin Webers, now that i have had another made for ET1 head i'am switching to this engine untill i get my A20 fully built to a really insane specification which will take about a year to 2 to finish. The ET1 engine found in 1st gen lude and 2G accords in U.K is a very good design, very nice head and uses the smae gearbox fixings as the later 2g ludes and 3g accords so can have nice ratios for racing. I would stick with A20 as it is, if you want to raise the CR ratio then do it by skimming the head and block deck and if you want it really high then forged pistons is the best way to go. Having a smaller combustion chamber does not aid flow into the cylinder it hinders and flow is what gets you the most BHP, but with a well flowed chamber and a high CR ratio piston your gonna be laughing!!

[phrenology]

Well right now I'm more concerned with getting my car put back together in running order. I was just toying with the A18/A20 combo because it seemed like it was a cheap and easy upgrade to do. Right now my goal is to build a really reliable but powerful motor. So far if you have read my other posts, I have taken my A20A3 block +.020 and shaved down the head .025 so that alone should give me a bit more torque/hp. I've had the block blue printed and professionally rebuilt with new pistons and rings. The crank has been balanced too. I had the head tweaked out a bit too and I'm going with the ET1 Prelude cam which I'm gonna have ground. Bigger valves, stronger springs and new valve seats are down the road abit. I'm gonna sandwich a nice custom copper gasket between the head/block. The mixture is gonna come from my two DCOEs and a custom built intake manifold. As for the tranny work I bought a completely warrantied rebuilt EQ25 manual which according to my research has the best gearing for my higher torque application out of any of the 3G trannies, I might play with the final ratio later. I'm getting a dual surface clutch and having the stock wheel lightened and balanced. That's pretty much the plan for now, again this is going to be my reliable ride for now and the racer comes later.

[rjudgey]

i presume your using a A20 head?
Sounds good so far what DCOE's you using? 40' or 45's?
You should be able to get a reliable engine i found that if you keep the revs at 7K and below the cast pistons last much longer, higher than that you will need to change them every 10-15K, also with the gearbox, very strong unit but only in road use or drag use, if you use constantly on track it will not last long as it really needs an oil cooler but that can be fixed with an electric oil pump, cooler and some hosing, same goes for the engine, get an air to oil cooler if using webers.
Have you got a cardomain site? Sounds like a good little project!!

[85manw/a plan]

so its true, you can swap an A18/A20 head on a 2.5 ES2 engine????
and also make it a 2.0 by a rebuilt

[PhydeauX]

No, you've got it backwards. You should be able to put an a20 head on an es2 but there wouldn't be any displacement increase. You could put the ES2 head on the a20 block and create a 2.0l ccvc engine for what ever reason.

andy

[2ndGenGuy]

No, you've got it backwards. You should be able to put an a20 head on an es2 but there wouldn't be any displacement increase. You could put the ES2 head on the a20 block and create a 2.0l ccvc engine for what ever reason.
andy

Maybe to be the worlds only 2 liter CVCC engine? Perhaps to impress Honda engineers at how clean your 3g Accord runs? Or maybe you want your head to be more prone to warping and blowing head gaskets...

[newaccorddriver]

Maybe to be the worlds only 2 liter CVCC engine? Perhaps to impress Honda engineers at how clean your 3g Accord runs? Or maybe you want your head to be more prone to warping and blowing head gaskets...