4age Rebuild or replace question

[mlewis]

Hey guys just found out my freshly rebuilt 4age bluetop in my ae82 wasnt so freshly rebuilt. The guy did everything right including a run in period he claims but then finished off telling me he used to rev cut the motor in 2nd gear, would explain why my 2nd gear sometimes pops out when at low rpm going into a round about.

The engine has now developed a serious knock and also looking at replacing

My question is can i get away with just replacing the bearings, or am I going to have to rebuild the bottom end again?

In which case leads to question 2. should i just replace the 3rib block with a 7rib block and reuse my head, as im aware the 7 rib blocks are alot stronger and handle a bit more abuse without being tempremental. theres also the chance or a turbo sitting on the side of it for a tame 8-12psi which ive read you can do quite easily on a 7rib factory block and internals apart from the 20v BT

Any suggestions and advice is much appreciated

[Lloyd]

Turbo will always come down to budget.

Rebuild generally wont just be bearings, especially if it's knocking. At best you'd get away with cleaning up the crank or go slightly oversize and use bearings to suit. Though if you're going that far then you'd want the rods out and checked, which means the head off. And if you're going that far then you're most of the way to a rebuild anyway.

[mlewis]

So comes down to rebuild or replace? I'd rather replace the bottom end to get the extra strength of the 7rib block and stronger internals

[Lloyd]

If you're replacing then you may as well rebuild the replacement engine also, that way you know where you stand with it. Rather than throwing in an unknown condition engine and having this same thing happen a few months down the track.

[mlewis]

yea realised that after posting, how much boost could a stock bluetop bottom end take?

[Stu-]

I've seen 14psi on a TD04 with a good tune last a year or two of hard use. Its all in the tune

[allencr]

What's the compression?
No, replacing only the bearings will not fix the crankshaft journals.
Popping out of 2nd gear has zero to do with the engine & whatever 'rev cut' means, only the trans internals & its shifter cables.


There have been many posts about 'knocking' that were really about a bad ex. manifold gasket/s or almost any/everything else. Sure about yours?

[Pelo]

Popping out of gear can often be worn engine mounts too, might be worth checking.

[mlewis]

sorry "rev cut" im guessing the old owner ment by redline launching or revving in 2nd to the redline and having it cut out, like a fuel cut or something.

I am going to have a closer look at it tho now theres suggestions it may not be a bearing. my partner did comment sometimes it engine sound become louder, but then so did the knocking.

Will have a look at it over the weekend and drop the oil and have a look to what comes out.

[mlewis]

havnt checked the compression, will have a crack at that over the weekend aswel, does anyone have a compression tester in wellington i could borrow for a quick test?

[AE86fan]

Not sure if you have thought about a 20 valve conversion?? Everything is pretty much bolt in with some rewiring. If you have a good hunt about Im sure you could get a motor with lower Ks that you wont have to rebuild. Turbo is great but the reality is, less reliability unless you spend some money on internals and tuning, more time getting it fixed than out driving it.

An Ae82 is a great car and with a tidy reliable 20valve setup will be easier to drive, less hassel with WOFs and be more sellable.......

just my thoughts from someone thats been down that road and is over rebuilding motors....

[mlewis]

That was the original thought but don't have that kind of money free at
, turbos just a thought for the future. I'd be happy just running a small port