7M Losing Compression

[driftboi]

I'm currently working on my Mk 2 Drifter Project just drop in a 30,000 miles
7m I just got done working on it but the only problem was the car ran very poorly. Test the compression and they were preatty low. Am I better off to replace the rings or just rebuild the whole motor?

 

[Yellow 13]

Does the place you bought the motor from warranty the motor?

Did they test it at all?

 

[supramacist]

First of all that 30k mile is a guesstimate on the part of the distributor.
What these guys do is part down old core engines and build new engines with whatever they have that is left from bone yard.

If you bought a JDM then you probably need to rebuild atleast from the MHG up. That block may have 100k on it you don't know and you never will. Unless you bought it from someone you know.

The 7m's are incredibley easy to work on so long as you mark your vac hoses clearly. It's a judgement call and a gamble no matter what you do, to be perfectly honest.

 

[driftboi]

First of all that 30k mile is a guesstimate on the part of the distributor.
What these guys do is part down old core engines and build new engines with whatever they have that is left from bone yard.

If you bought a JDM then you probably need to rebuild atleast from the MHG up. That block may have 100k on it you don't know and you never will. Unless you bought it from someone you know.

The 7m's are incredibley easy to work on so long as you mark your vac hoses clearly. It's a judgement call and a gamble no matter what you do, to be perfectly honest.

Whats MHG? Isn't that a main head gaskets?

 

[akito]

MHG= Metal Head Gasket!!! I would also suggest you do as he said, those jdm engines...who knows what they can do.

 

[osiderida06]

Metal Head Gasket.....

 

[driftboi]

Metal Head Gasket.....

Thanks for all the help I'll keep you guys posted!

 

[upgradedsupra]

Define loosing compression..What it is exactly? Are they even all across?

Duane

 

[driftboi]

Actually some of the heads were in the 50 PSI zone and some where in the high 80s. I'm thinking it might be time for new rings unless this engine has been over heated.

 

[cuel]

Rebuild it. If your making a race car, you're much better off with a fresh motor anyway. Especially if you're gonna be putting a power adder (turbo, nitrous) on it.

 

[driftboi]

Any one know any parts store that sells 7MGE rebuild kit?

 

[PROJECT N00b]

ask aaron at driftmotion, he might be able to give you some pointers and stuff...oh BTW its "losing" not loosing.

 

[CRE]

What makes you think it's the rings? How precisely did you test the compression? What was the compression from each cylinder? (1 - 6) Then what was it with a little motor oil poured in each cylinder? Are the cams and crank all set properly to 0º?

 

[driftboi]

My buddy test them 1-6 how he test them he hook up the test to one cylinder and crank the motor 3-5 times. But just this morning I had remove the head and I just found out its not the rings. Came out to be the head has a crack. Now somthing tells me the engine been over heated :madfawk:

 

[cuel]

I'd most certainly rebuild it now. If it got hot enough to crack the head, then the rings and bearings are damaged. You can just slap a head on if you want to(its your car), but it won't be long before it spins a bearing or breaks a ring. Especially if your gonna be putting it through the torture of racing it.

Good luck.

 

[driftboi]

ask aaron at driftmotion, he might be able to give you some pointers and stuff...oh BTW its "losing" not loosing.

Thanks for catching that :icon_bigg

 

[PROJECT N00b]

No problem, I'm a decorated spelling bee veteran.

 

[driftboi]

I had made up my mind to drop in a 7M GTE that i'm plannning to buy an engine from Nix 99 in Everett for $1,200 they tested the engine and said its in good running condition.