calling all engine builders - need help, ?'s

PittSpeed Automotive PittSpeed Off Topic
1

1990 talon AWD (but it’s more anyone with any experience with OHC setup)

well after the car didn’t start for the third time we pulled the motor and took it to a shop. here’s rundown on this car:

  1. tensioner pully siezed, melted belt
  2. had head rebuit, started for 20s then bent all valves
  3. had head rebuilt again thinking problem #2 was a belt skip put the head on the car tried to fire, no luck, compression test - 0 comp.

so we took the whole motor and head to the guy that built the head in the first place, timing marks line up, crank pully key still in tact, all 16 valves bent.

here is the diagnosis. the intake valves opened, then when closing they didn’t close all the way so the exhaust valves got caught and then tried to close but couldnt and bam pistons hit them. (this is on initial startup mind you)

his theory: the lifters aren’t seating…but yet we had the head set for 2 days before we put it on the car for this very reason(even after we cleaned them and didn’t prime them for this reason too) the valves were closed and we turned the motor over by hand at least 20 times to check, i highly doubt i could turn the motor over with valves that aren’t closing all the way.

the guy has been on the phone with mitsu for the past 3 days while putting the motor back together (reputable shop out here, years of engine work) trying to blueprint the motor to find the problem.

any thoughts that i can relay to this guy on things to check?

2

well i copied the URL and sent it to my buddy with a 91(i think) TSI that ran a 12.4 befor a few new mods he might know so hopefully he gets back to me.

3

here is what my buddy sent me :

the hydraulic lash adjusters should be pulled, cleaned (see www.vfaq.com for that plus timing belt install), and to replace all pulleys and belts on the motor. this includes balanceshaft belt, balance shaft tensioner, timing belt, timing belt tensioner pulley, t-belt idler pulley, and t-belt tensioner. www.partznet.com has good discounts on these items. www.vfaq.com and www.dsmtalk.com will be loads of info for this question

oh yeah, after cleaning the hydraulic lash adjusters, pump them with oil (while keeping the valve open, just so they’re lubed) and then install them soft. this can be found more in detail with a search on dsmtalk. ttyl

and one more thing i just thought of…they may have the cam gear marks lined up right, but the cams are 180* off. there’s a key that goes into the cam gear, a little stud of sorts, and they should face down.

also, with the t-belt job, might as well do a water pump too just to be safe.

let me know what they say then.