Help With My Heavily Modified 4k Pls

[Lumpy_4k]

Hey guys,

 

I'm just about to go pick up my new KE20 that i scored. I am wanting to transplant the engine/5spd tranny out of my old KE55 into it which will hopefully be pretty straight forward...unless someone can tell me otherwise. Anyways my problem is this.... my ke55 has been off the road for about 10 yrs (will require a rebuild i know) when last driven, or attempted, she was backfiring and shooting flames out of the carby. I have spoken to a few people and have had numerous responses as to what the problem may be, these include...bend push-rod, cam timing out, ignition timing etc etc

 

The engine specs are as follows...(by memory)

80/40 reground cam

ported and polished head shaved 20 thou

block shaved 40 though and bored 60thou over

flat-top pistons with chrome-moly rings

oversized stainless valves with double springs

custom manifold to suit a 45mm webber of an XF falcon

maybe a few more mods but can't think of them at this stage.

 

The engine was running sweet and used to eat alot of cars. By memory the last time the car ran fine was when I was driving home from work in a foul mood and i may have valve bounced at around 9000 rpm. the next moring was when i discovered the problem. I took the tappet cover off and all vlaves where moving, I advanced and retarted the dizzy near on 180 degrees in 1 degree intervals to no evail.

 

Anyways any insight would be greatly appreciated, also any hints on the 4K/5spd conversion.

 

Much love,

 

Lumpy_4K

[altezzaclub]

Check tappet gaps for a bent valve and do a compression test.

 

Check head gasket too, although if it is bad enough to backfire you should hear it running rough. I assume the compression ratio is astronomical and that may be a problem area.

[Evan G]

my money is on bent valve

[kangaroosa]

Check you haven't broken an inner valve spring.

My throttle jammed at what once in my 5K, I switched it off and saw the tacho falling from 11,000rpm. The result was 2 broken inner valve springs, and a big drop in power with a misfire. Hopefully its as simple as that for you.

 

It doesnt explain the backfire through the carby as the single spring is enough to keep the valve seated. Everytime i've had a backfire through the carby, it was timing related. I would be resetting the timing from scratch.

Edited August 15, 2010 by kangaroosa

[SLW42]

Generally when a car backfires through the carby the timing is out 180, and it sucks when you cop a face full of fuel for your efforts too, that is what i have found working on old toyota's

[morgzz]

leads on the dizzy cap wrong?

adjust timing then you should be sweet

 

worked on mine.. all the leads were on the wrong buttons