why the compression difference?

[jt-juice]

i recently picked up a 93' and 94' stock lasers both fwd N/T 6bolt 4g63's. i'm getting compression reads of 160's across on the 93' and 215 - 220 on the 94'.

the 94' has a huge amount of bottom end over the 93' any ideas why such a dramatic difference between cars and why the 93' is so gutless and takes so long to wind-up in comparison?

 

[Tanro]

Sounds like you had some drop a Turbo 7 bolt in the 94 w/o a turbo.

fyi, its not stock if it is a 6 bolt and in anything post 92.

 

[jahjahSQC]

I was thinking along those lines ^^^^

Someone swapped in a turbo motor... with no turbo.

 

[jt-juice]

Sounds like you had some drop a Turbo 7 bolt in the 94 w/o a turbo.

fyi, its not stock if it is a 6 bolt and in anything post 92.

really? compression readings of plus 215 on an engine that was turbo'd? i've been reading alot that turbo'd engines run much lower compression? i was thinking more someone must have rebuilt the 94' engine with some "humphry" pistons oslt? several experienced local dsmrs tell me the 94 is a 6 bolt and i honestly can't tell a single difference between the two engines from the outside top to bottom both i've done alot of work to myself. both have no knock sensor etc etc

 

[90moneypit]

really? compression readings of plus 215 on an engine that was turbo'd? i've been reading alot that turbo'd engines run much lower compression? i was thinking more somone must have rebuilt the 94' engine with some "humphry" pistons oslt?

Either way, your answer lay in the compression difference causing the performance to drop along with the compression.

 

[Tanro]

Ah I ment the 93. Which ever one has lower compression is either

1) Turbo engine w/o turbo
2) Bad Rings
3) Bad Headgasket
4) Bent valves/Out of time

or a combination of all of the above things.

Cars Produced between 89-Early 92 - Came with a stock 6 bolt.

Later 92 and up is a seven bolt. Seven bolts came in both 1g and 2g cars. 1g Sevenbolts still have a 1g head, intake manifold etc.

 

[jahjahSQC]

really? compression readings of plus 215 on an engine that was turbo'd? i've been reading alot that turbo'd engines run much lower compression? i was thinking more someone must have rebuilt the 94' engine with some "humphry" pistons oslt? several experienced local dsmrs tell me the 94 is a 6 bolt and i honestly can't tell a single difference between the two engines from the outside top to bottom both i've done alot of work to myself. both have no knock sensor etc etc

Something with a compression of 160 across the board sounds like a turbo motor. Like.... 7.0-7.5 compression.

 

[jt-juice]

thanks for the info folks. i finally managed to get ahold of the fella i picked the 93 off and he said the engine was out of a turbo'd 1g talon. He couldn't tell me if it was a 6bolt or 7 or what year the talon was. Time to read up and see if i can verify my gut feeling that both engines are 6bolt.

 

[XiKeiyaZI]

Welp, slap the turbo components on that single engine and you have yourself a FWD Turbo DSM. The work has been done.

 

[jt-juice]

Welp, slap the turbo components on that single engine and you have yourself a FWD Turbo DSM. The work has been done.

can you recommend a good thread or a list of parts and mods i'm gonna need?

Something with a compression of 160 across the board sounds like a turbo motor. Like.... 7.0-7.5 compression.

will it hurt the engine on the 93 if i keep driving it everday from work and back since it was designed for a turbo system?

 

[jt-juice]

Something with a compression of 160 across the board sounds like a turbo motor. Like.... 7.0-7.5 compression.

i've confirmed that it's a 6bolt whoo hoo!!

 

[92AWDHX40]

Never saw a thread about that set up most just get a turbo block, remember its a turbo add all the mods you need. It may last it may not chances to take unless you have a back up car and dont mind it blowing up go for it.

 

[jt-juice]

Never saw a thread about that set up most just get a turbo block, remember its a turbo add all the mods you need. It may last it may not chances to take unless you have a back up car and dont mind it blowing up go for it.

the guy that owned it before me took the engine out of a turbo'd 92 talon and sold all the turbo gear and put the engine in the 93' fwd n/t laser. I feel gifted to have this engine and can't wait to set it up the way it should have been done from the start. The talon ended up written off at around 36 000 miles