16v bigport v 20v? Carbs v itb's?

[Matt]

Work gets me up sam.

Factory rev limit from memory on the blacktop is 200rpm higher being at 8400.

The interference on the blacktop is only due to the lift in the cams, but having said that if you keep your timing belt fresh and replace at the service intervals and that you should be ok. Allot of motors out there are interference.

The prices are definately all over the place, seen them as low as $1000 for a half cut 12-18 months ago and as high as $3000 just recently.

I guess the path taken will depend on availability and budget. People don't drive ae86's because they are a cheap run about anymore.

What do you currently have in the car?

[Rice86]

Best bang for buck for your application will be a standard 20v rebuild, depending on your budget too

will be very reliable and very cheap and easy to maintain and the standard power out put is more then enough. with an ECU you can already refine the tune..add cams then your pretty much done.

if a stock bigport 16v 4age with 150 000km can drift, i think anything can. Reason why i decided to stay 16v for now instead of upgrading where its not needed yet

4.3 - 4.7 diff ratio helps a lot! and thin tyres too

[Sam-Q]

I think the limit for a blacktop is 8200 and 7800 for a silver. However I was refering to after you change the factory limit. I wouldn't raise the blacktop limit however a silvertop should be fine at 8600 all day. There is a lot of debate about the limit of blacktop rods but they sometimes break and I have yet to see a silvertop rod go or bend. This may suit some more than others though, I find it really usefull to have the higher rev cealing.

I had a silvertop with a rebuilt bottom end and my own modified head inc porting and match porting. I from my own carelessness damaged a bearing in that so it will be repaired. In the meantime I am using a completly standard silvertop with my own home made intake and exhaust on it as well the same tuned ECU.

The reason blacktops are inteference isn't because the cam lift as it's only 0.2mm high on the intake. Rather it's the much higher dome of the piston. If you see one it barely has any flycuts in it due to it's shape. In my case twice I had the keyway part of the pulley break and the key wind out. This stopped the cam belt drive puley from turning. I was doing 8500 the first time and I had a 0.8mm TRD gasket so 0.4mm thinner. After that I became rather annoyed and pressed a steel ring over the outside of the pulley.

[Matt]

Ah cool, a co-incidence it is the same amount of lift where the 16v becomes an interference engine also. Happy with that explanation / logic... When i get into the shed next i'll post up a pic of both pistons side by side.

But yeah, agree with the comments best bang for buck is with the 20v engine... If you are handy on the tools grab one from an importer, wire it up, swap the timing belt and throw it in.

[timbo]

I love my smallport. High comp with a shaved head and TRD 0.8mm HG, bigport cams, TRD copy headers with 2.24" mandrel bent exhaust. I have been told it pulls like a 2 litre! Drag time of 15.6 seems reasonable enough to support any claims (plus I am surely the worlds worst drag racer).

I guess 20v is better, but I think if you want less fucking around a healthy smallport is so much fun. You just have to cut and shut the manifold, as opposed to relocating the dizzy and all the water pipes with a 20v. Mind you SamQ makes all this stuff now...

edit: Toda 3.6kg flywheel helps.

[BMXB]

wow thanks heaps for all your help everyone!
my 86 has a 4age 16v redtop right now, has about 120,000k's on it, goes great and revs super quick but im keen on finishing off the build with a sweet motor under the hood.

i have also brought some cisco engine mounts thats why i wanted to know about the mounts.

if anyones running a 20v that might be keen on a swap or anyone selling one at a good price let me know?
thanks again for all your help!

[sotiros86]

Why not just throw some quads, cams and an ecu on your 16V? Itll be less hassle, still drive really well, and be cheaper than going 20V.

[Sam-Q]

should you happen to visit the south eastern suberbs you could just drop in to my place and see what a bog stock 20v is like with a tune + mediocre intake and exhaust.

[marvis]

Quad carb 16v bigport 7 rib.

Win.

[lolwat]

spend nearly 600+ on plates, trumpets, throttles them selves, Buy whole 20v for 800??? please explain your theory?