4a-ge

[KnightX_AE86]

i know theres 2 diffrent 4a-GE motor.... one is a red top and onr is a blue top??
can ne1 post the pic of the 2 diffrent motor up for me so i can have a look n see if i have the red or the blue top motor??? and i heard that the red top needs high octane gas?? like how high of n octane does it need??

i have a 4age and i dunno if iv been sing te right kinda of gas for the car... coz lately the car has been jerkin around when im dirving so if sum1 can post the 2 pic up for me it'll b great.. thx

[REN69]

You have an AE86.. The 4AGE in your car.. that's a blue top.. its got TVIS.

There's 2 redtops but both are non TVIS. One is AFM sensored and one is MAP sensored.

[89yotarollagts]

The JDM spec redtop engine would need the high octane gas but not the US spec engine i dont think the difference in octane would cause any jerking maby a knocking sound ?

and REN areu talken just the ae86 cuzz my Ae92 has TVIS

[KnightX_AE86]

ummm im not so sure if its a blue top tho... this car was not made in the us.... i went on the forms and looked at the VIN thing..... its made in japan?? just to b safe can sum1 just post the 2 motor on here?? (pic)
thx a million

[hachi_slow]

how many ribs does your engine have? 3? 7?

FYI, they were all made in Japan (ae86s). I'd agree with Ren. You most likely have the bluetop.

Why don't you post pics of your engine and we'll tell you what it is.

[project trueno]

Originally Posted by REN69

There's 2 redtops but both are non TVIS. One is AFM sensored and one is MAP sensored.

no man...

To avoid confusion, we really should stop refering to the varying 4age's by valve cover colours. When it comes to naturally aspirated 16V's, there are THREE versions.

"Bluetop" would be the 1st generation, featuring BIG INTAKE PORTS, 9.4:1 CR, because of the BIG PORT design, T-VIS was adapted to the engine to aid low end torque. Found in early AW11s, and AE86.

2nd generation, same as above, BIG PORT with T-VIS. However the block external has 7 ribs for strength, otherwise its the same old 9.4:1 CR 4age. Found in typically 1987 (last year) AE86s, maybe some AW11s, and early generation AE92s. When found in the AE86, it has blue lettering on top, in the AE92, blue and/or red lettering. Often refered to as a "redtop", but ignore the red lettering becuase it is still a BIG PORT aka "Bluetop"

3rd generation. SMALLPORT head, T-VIS system is eliminated. Bottom end has 10.3:1 CR pistons, also 7 ribs on the intake side of block. Has external oil drainback hose, oil squirters. Found in the last year of AE92s, and Geo Prism GSi. If you want to use colours to identify engines, then this would be the TRUE redtop.

There are other detailed differences between the 3, but if I make the post too long I find no one actually reads it, and they ask the same questions again. All 4AGEs in North America will be equiped with an AIR FLOW METER. Regardless of what colour "top" you have. The only exception is the Geo Prism Gsi, that 4age is MAP sensored.



Again, BIGPORT has TVIS, SMALLPORTS do not. If you see TVIS, assuming previous owner didn't play frankenstein on your 4age, then you have a BLUETOP. If you don't see TVIS, you have a smallport aka REDTOP.

See how confusing colours can be? Just remember BIGPORT and SMALLPORT.

[Kwanza]

There are a bunch of versions of the 4AGE. Calling them "redtops" and/or "bluetops" is HIGHLY inaccurate for a LOT of reasons, the most obvious being the ease of swapping valve covers.

Basically, there are 3 MAJOR versions of the 16V 4AGE. The old bigport 4AGE "bluetop" which had light internals, TVIS, 18mm pressfit piston pins and 40mm crank journals. These are common in the MR2, AE86 and AE82. These BOTH came MAP sensored and with AFMs. The later models made during the later half of 1987, these same engines also used the 7 rib blocks. For the most part, these are all 3 ribbed blocks. These can run normal grade octane (87).

The second revision, the bigger internal bigport 4AGE... These are also considered "redtop" which is VERY VERY misleading and is often confused for the 3rd revision. These had float design 20mm piston pins and 42mm crank journals. They also used TVIS (bigports all used TVIS), had 7 rib blocks, and heavier/stronger internals. They actually made slightly less power and were slightly less responsive than the older "bluetop" bigports that came in the AE86s, early model MR2s and AE82's. These can run normal grade octane (87) and came most commonly in the AE92 and later model (1987.5-1989) MR2s. They were available MAP sensored and AFM.

The third revision was the smallport "redtop" 4AGE. These maintained much of the same in the block as far as the crank journals and rods go. They however used high compression pistons (10:3:1). The head itself is quite different. It was not designed to utilize TVIS so the intake ports are designed much smaller for higher velocity. Overall, it's a much better head than the bigports (IMO). These did require high octane fuel (91-92) and came in the late model AE92 (1990-1991) and Geo Prizm GSI (1990-1992). These were available MAP and AFM.

[project trueno]

knightx your car comes factory equiped with a bigport. Its acting up becuase its aged, go fix it.

[KnightX_AE86]

ya i know its acting up but does ne1 know wut it might b the prob??? coz when i first got the car a month ago the car ran great... (i didnt rev her more then 5g) then after like2 weeks it started acting up..... does that ring a bell to ne1 wut the prob right be.... im gonna go it to my budd's shop on monday (KSRD) n hes gonna have a look at it for me.. but i'll save him alot of time if u guys can give me sum commends of wut it might b..... it'll save him time and my money.... ya kinda running low on cash after the stupid battary and the altenater and the rest of the little things i had to get for the car.....
thx guys for helpin out

[REN69]

Originally Posted by 89yotarollagts

The JDM spec redtop engine would need the high octane gas but not the US spec engine i dont think the difference in octane would cause any jerking maby a knocking sound ?

and REN areu talken just the ae86 cuzz my Ae92 has TVIS

the AE86 and 92 both came with blue tops.. and I was talking about bluetops in general... I also have an AE92 with TVIS so I guess I would know.

And I believe the US spec redtop also requires 91 octane.

[lammi_rolla]

i have a "redtop" 4A-GE, but im new to the whole scene, the car is an 87 seca, should i be using high octane fuel

[REN69]

Was the motor changed?? if its the original one then its not a redtop... its a blue top.. red tops didn't really come out until 1990.

[VooDoo]

re the problem,

it could be many things... from a fuel delivery problem (fuel pump and/or fuel filter and/or fuel reg and/or injectors) to an electrical problem (i,e. faulty fuel pump wiring, worn plugs, busted high tension wire, busted dizzy, etc.). imho, easiest to check is the fuel filter... make sure its not clogged. if you they type who'd join fear factor, try taking the fuel filter out and blowing into the inlet nozzle... air should come out of the outlet without any problem. if this isn't it, try checking the plugs and wires.

hope this helps.

[toyotaspeed90]

ren.... stop posting in this thread! you keep getting it wrong.... NO ae92 got a "bluetop"..... some specs:

ae86 (through 1986), ae82 gts, mr2 (through 1986), twin cam chevy nova (rare)
bigport
t-vis
240cc injector, low ohm (blue... supposedly smaller, but after testing people are reading over 240cc/min)
3 rib block
40mm rod journals on the crank

1987 was the weird year.... they were changing the 4age for 1988 and so the 1987 years got weird parts..... for instance, my 87 mr2 came stock with a 7 rib block, low compression pistons, t-vis (obviously), 240cc injectors, but a later wiring harness

ae92 gts (88-89), mr2 (88-89), geo prizm gsi (88-89)
bigport
t-vis
240cc slightly higher ohm (different resistor pack), tan color
7 rib block
42mm rod journals on crank

ae92 gts (90-91)
smallport
no t-vis
250cc high ohm injectors (greentop....)
7 rib block, some had oil squirters as well
42mm rod journals on crank
higher compression pistons

that i know of, the ONLY map version 4age in teh US was the very rare 1992 geo prizm gsi...... and even then, the map versions were rare in the US...... i've only heard of people online seeing one or 2 of them in the past 13 years

[REN69]