Does anyone have a deffinitive answer to how the twin carb ea71 differs from the single carb version?

 

Is it just the manifold and carbs or are the heads and block different in some way?

 

Cheers

 

Dirk

just the carbs an manifold as far as i know

The Valves and ports may have change aswell.

 

-Tom

Er Thanks?

 

Not quite the definitive answers I was looking for though.:-\

If I'm not mistaken the dual carb was on the "sport" model this was a higher RPM engine (7000) so most likely it had bigger ports, larger valves and a hotter camshaft.

I know with the EA81 series that the intake and exhaust ports were reversed on the dual carb heads (intake ports in the middle next to eachother and exhaust on the outside). This also meant the cam was reversed as well. I would not be surprised at all if the EA71 dual carb motors had a similar setup. Either way the blocks will be the same.

Pretty sure the EA71 dual carb motors weren't like the EA81 dual carb motors... Just standard EA71 with a dual carb manifold... Although it might have more compression. The EA81 version had 9.5 vs 9.0.

 

You are asking in the wrong forum, don't complain when you don't get the perfect answer...:-\

sorry. So which one should I post in?

Pretty sure the EA71 dual carb motors weren't like the EA81 dual carb motors... Just standard EA71 with a dual carb manifold... Although it might have more compression. The EA81 version had 9.5 vs 9.0.

 

You are asking in the wrong forum, don't complain when you don't get the perfect answer...:-\

 

Did you actually read this before posting? You managed to contradict yourself in the same sentence.

 

Also, can you explain to me why you think this is the wrong forum for my question?

Really this question should be asked in the "50s - 70s gen forum" this forum is really for anything EA81 to anything pre-EJ.

 

Best of luck on finding your answer

 

-Tom

Oops!

 

Cheers Tom. Sorry Thomas.

 

Altough I'm sure they continued the EA71 into the Eighties. ??

Edited November 13, 200916 yr by Dirk

Oops!

 

Cheers Tom. Sorry Thomas.

 

Altough I'm sure they continued the EA71 into the Eighties. ??

 

Yes, very ture. in s ome countrys the 1600 EA71 was standard in the EA82 style cars. So yep it was continued into the late 80s - but its still 70s technology carried on to a later date (Just like the EA82s, carried on till '94)

 

-Tom

Really this question should be asked in the "50s - 70s gen forum" this forum is really for anything EA81 to anything pre-EJ.

 

Best of luck on finding your answer

 

-Tom

 

And the EA81 was basically an updated late 60s design carried into the early 90s in some countries. "if it aint broke dont fix it" seems to apply well here.

..

Edited November 13, 200916 yr by DR DLEX

If I have my history right,the duel-carb was only offered on the EA-62 or

63(1400)in 1972-74 in the U.S.These engines had the valves reversed

with the exhaust ported to the side of the heads(not under).The manifold

does fit the EA-71(1600),but you have to re-jet the carbs to keep the

air/fuel mix right.The next adjustment would be the exhaust.The stock

exhaust fills up to quickly and tends to get hot and burn the inner pipe

at the head.

Now since you live Down-under you may find EA-71(1600) D-C engines.

A side by side tear down would answer alot of questions(heads,cams,

compression,jetting,dist,etc).

I've been running D-C for a while now on my stock EA-71(1600)block(s)

and head(s).Don't expect any more than +25HP and +20 torque,and you

will be happy.

Bye the bye,I like those heads in your build thread.The car is in very

good shape ,too.Is that factory green?

Bye the bye,I like those heads in your build thread.The car is in very

good shape ,too.Is that factory green?

 

Cheers. Yes. Its Sprite Green.

if the ea62 had fliped valves then my guess now is the 71 would of too just like the 81. So that means dif cam and heads as well as manifold...

Ive seen a 1981/82ish 1600GLF coupe. It had twin carbs but I dont think it was it had any of the fancy heads etc. It was very odd ball.

 

Wouldnt it only be the 1976ish RX coupe that would had been fitted with fliped valves, dif cam, heads and DC manifold???

Ive never seen one here. Only seen pics and brouches from Japan about that verson

I think I've sussed it!

 

Spoke to a fella who has a few of these engines and he said: Yes they do have 'hotter' cams, bigger valves and higher compression. Gold star to those who suggested as much.

 

He also went on to say that retro fitting a dual carb on a stock engine will only cause it to burn more fuel. Although it would appear that other people on this forum have had other experiences with this. More opinions on this welcome!

 

Unfortunately this is about as much info as he was willing to give. I get the impression I gets tired of dishing out free advice all the time. Shame, because he could be a real asset to this forum.

 

Cheers to all who passed comment.

I think I've sussed it!

 

Spoke to a fella who has a few of these engines and he said: Yes they do have 'hotter' cams, bigger valves and higher compression. Gold star to those who suggested as much.

 

He also went on to say that retro fitting a dual carb on a stock engine will only cause it to burn more fuel. Although it would appear that other people on this forum have had other experiences with this. More opinions on this welcome!

 

Unfortunately this is about as much info as he was willing to give. I get the impression I gets tired of dishing out free advice all the time. Shame, because he could be a real asset to this forum.

 

Cheers to all who passed comment.

 

Who was it that you chatted too?

Who was it that you chatted too?

 

Robert Jopson, Cromwell Auto Recyclers. A great source for gen1 parts. He is quite the subie fanatic and also a well knowen face at speedway tracks. Actually he used to own my car.

 

I like him a lot and he has always been good to me (if a little kurt at times), but he does have a reputation for being a little difficult at times. I hear he was banned from racing last year because he verbaly abused a track marshal.

 

He has a couple of spare twin carb engines too but is reluctant to part with them right now. Bummer.

Robert Jopson, Cromwell Auto Recyclers. A great source for gen1 parts. He is quite the subie fanatic and also a well knowen face at speedway tracks. Actually he used to own my car.

 

I like him a lot and he has always been good to me (if a little kurt at times), but he does have a reputation for being a little difficult at times. I hear he was banned from racing last year because he verbaly abused a track marshal.

 

He has a couple of spare twin carb engines too but is reluctant to part with them right now. Bummer.

 

I thought it mite had been him. I was trying buy a GSR of him ages ago but then he desided he didnt want to sell it.

I thought it mite had been him. I was trying buy a GSR of him ages ago but then he desided he didnt want to sell it.

 

Did you see the one on trademe in Aukland a few weeks ago? I was pretty keen but I think the wife would have divorced me. (which is a bad thing cos she's still hot and looks after me pretty good)

He also went on to say that retro fitting a dual carb on a stock engine will only cause it to burn more fuel. Although it would appear that other people on this forum have had other experiences with this. More opinions on this welcome!

 

From what I have read it is simply not true dual carbs will cause an engine to use more fuel. In some cases the opposite may be true.

I know the EA81's had reversed valves, hotter cams, higher compression, etc for the dual carb engines. Being that there is good evidence that this was true of EA62/63's, I wouldn't think the EA71 to be any different.

 

Even the EA81 in dual-carb was only 108 HP, though there are rumors that race prepped versions put out more - as much as 150 HP or more. I've never seen actual documentation to this effect but I have seen pictures of EA81 performance engines and components that were obviously upgrades to the "stock" dual carb setups. Race engines with no manifold - just two carbs mounted directly to each head, etc. Dual exhaust port heads and header's for EA81 RX coupe's.....

 

I wouldn't be at all surprised if someone came up with documentation claiming 175 HP from an EA81 in race trim. Closer to 200 with turbocharging though I don't know if that was done outside the US. The basic engine can handle it - RAM performance has a 200 HP build for aircraft use.

 

GD