RedTop Engine?

[NoHachi]

I've heard the exact oposite as well...that the redtop lacks a lot of torque and off-line response, but flies when it comes on the cam. Sounds logical to me, they produce more horsepower afterall, so somewhere it needs to gain on the bluetop. Also the bluetop has tiny runners untill the tvis plate opens, so it should be torquey.

[Mux213]

Nohachi,

yeah thats the weird bit, in theory the tvis idea in combination with the big port system should always produce a higher power curve then the small port engine. But they say that the better flow of the smallport combined with the cams just make it a better design then the tvis/bigport engine but that it looses in revyness and responce due to the heavier parts used in the stronger underblock.

What is actually true?!!? I haven't driven a stock redtop engine and compared it to my bluetop to actually find out, nor seen a dynosheet. It would even be kinda like comparing appels with pears. Is the difference the head, the block, or all the other bits.

What you really should do is take a 3rib block, dyno it with a bigport head, then dyno it with a smallport head, and find out which head really performs better.
Then do the same with the 7rib block

Probably someone has already done this.

For now, I simply keep to the rumor, redtop engine gives more power, bluetop engine is rev happier.

[Michel H]

I have driven a Redtop AE92 once and compared to the Bigport AE92 it felt boring. It was a bit faster although I must admit I expected more from it. Power delivery is like a flat line, nothing compared with the TVIS effect.

I would say the Redtop is the most boring engine of all 4A's (stock, that is..)

Edit: Last year we went to the dyno with both a Redtop AE92 and at that time my AE92 still had the 7ribs Bigport. Mind you the Redtop was rebuilded to spec and my Bigport had like 220.xxx km's on it. The numbers were not really aspiring and logical but it was nice to see the difference between different engines anyway. The Redtop had just 1hp more then my Bigport.

[Dorito86]

I swapped my stock bluetop for a stock (rebuilt) redtop coupled with a stronger clutch plate and 4.7kg flywheel. Difference is practically not worth the hussle of finding one in good condition, unless of course you are planning on pushing the engine to mild or full race specs where the added strength comes into play.

I also had a go from rolling 3rd gear against a stock bluetop hachi. We hit the gas at 2000rpm, and I made a slight difference of about 1m by the time we changed to 5th.

So, for fast road use, I'd stick with the blue top anyday, plus it keeps the car original (which will raise its market value in 10 years).

[NoHachi]

So the verdict on the redtop? Yet another toyota engine that came vastly overrated from the factory..seems to be std buisiness practice with them (just add 20hp).

[Michel H]

NoHachi Wrote:So the verdict on the redtop? Yet another toyota engine that came vastly overrated from the factory..seems to be std buisiness practice with them (just add 20hp).

lol yes exactly. One would think this overrating wasn't only about the 20v's heh

[SutteR]

I will explain the differences after we rebulid the newly gathered smallport and install in my car.

Smallport slightly tuned can do interesting things as I've heard regarding power output. I don't know why but my friends smallport seems that it likes the high revs more than the bigports in the 'neighborhood'. It's logical what you say about heavier parts in the engine block but the experience is the opposite for me.

I don't know, I hope it worth the money and effort...

Edit: and one more thing. Don't forget the different ECU - it might control the engine better than the old ones...

[filh]

well , now I'm a bit lost between red and blue top.I though smallport was a better evolution of bigport, but it looks like both have their own advantages!!!
My engine (used in rallies only) is so tired and ready for retirement....
I noticed an other difference , I think that piston axles come with pins bearing. that's a good thing to avoid cylinder wear .
As I'm reading here , it's seems to be a hard work for the gain (I mean swapping my old bluetop with a red top into my rwd ae86).
i'll take time for reflexion .
Filh

[Ivan141]

Get a 7-rib block... there are older types with regular compression cilinders but with bigger internals just like the redtop.
That would give you the advantage of being able to upgrade to high compression pistons if you feel it's necessary.
I cant help but like the good o'le TVIS these days though. It makes such a nice sound at full throttle.

[SutteR]

Ivan141 did you hear any smallport roaring yet? It's also great.

Btw I think one thing is sure: all version of the 4A-GE rocks!!