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View Full Version : a few questions about checking an engine - N/A or TT? Compression#s without flywheel



gs1000kat
01-11-2011, 02:02 PM
I have a shortblock was supposed to have been a 2 bolt VR4 engine. In trying to sell it, someone pointed out that the heads were N/A heads by the markings on them. Well, now I'm concerned about the shortblock being N/A as well. how can I tell the difference without tearing it apart? i will eventually, but I want to test Compression #s forst

Which leads me to my next question. What is a good way to turn it over enough to get a good compression test? All I have is an N/A flywheel(smaller diameter from what I can see), and no N/A trans to mount the starter to. I tried using a breaker bar on the crank pulley, but just can't turn it over fast enough or long enough. Considered using my impact gun, but even with the plugs out of the cyinders, I was concerned about breaking or stripping something. Would be possible for a 1/2 air ratchet would work?

CoreyB
01-11-2011, 02:33 PM
The block will have oil squirters in it if its a TT.

But you would have to pull the pan to see that.

RL7
01-11-2011, 02:44 PM
I think you may be able to get away with bolting that plate (the one that sits between the engine and transmission) to the engine and bolting the starter to that. It would be better if you had multiple plates though and I would probably run a strap around the starter and engine to keep it from moving around while cranking.

gs1000kat
01-11-2011, 02:45 PM
The block will have oil squirters in it if its a TT.

But you would have to pull the pan to see that.

thanks for the reply.

I can probably pull the pan, just didn't want to pull the heads so i can get compression. Unfortunately, as many years as I've had these cars, never seen the squirters. What am I looking for? What do they look like?

CoreyB
01-11-2011, 02:54 PM
At the bottom of each cylinder there is a little bump out that the squirter is in. The oil is fed from the mains.

gs1000kat
01-11-2011, 03:19 PM
Cool. I'll try to check that out soon. Thanks a lot.

Anyone have any thoughts on checking compression

Hans@GZP
01-12-2011, 09:43 AM
Just look at the end of the crankshaft where the flywheel bolts to it. If it has a dowel pin in it, then it's a vr4 engine... if there is no dowel pin in it, then it's a NA engine. Now, that's not a totally true way of telling since the engine could have been opened up and cranks could have been swapped.

Looking down the spark plug holes, you could try to see if you can tell if "72T" is cast into the top of the pistons.

If you pull the pan, it's extremely easy. The 2 bolt main girdle will have 4 stay brackets bolted to the main girdle to the block with some 14mm bolts. There will be 2 on each side of the girdle.

There is also a VIN number stamped on the block by the rear head on the transmission side. Just run the VIN on the block (that is if it's a US Spec engine) and see if it comes from a TT :)

As for comp numbers... that's going to be next to impossible without using a starter. You'll need to spin the engine at about 400 rpms to get decent numbers.

gs1000kat
01-12-2011, 03:35 PM
Pull a plug and shine a light down the hole. You'll be able to see the top of the piston if it's in the right place.
You'll even be able to see if it's a dished or domed piston. Might even be a stock flat top too.

Steve

I kinda tried that, but couldn't see much. Possibly the light wasn't bright enough or direct enough. I may try again tonight


Just look at the end of the crankshaft where the flywheel bolts to it. If it has a dowel pin in it, then it's a vr4 engine... if there is no dowel pin in it, then it's a NA engine. Now, that's not a totally true way of telling since the engine could have been opened up and cranks could have been swapped.

Looking down the spark plug holes, you could try to see if you can tell if "72T" is cast into the top of the pistons.

If you pull the pan, it's extremely easy. The 2 bolt main girdle will have 4 stay brackets bolted to the main girdle to the block with some 14mm bolts. There will be 2 on each side of the girdle.

There is also a VIN number stamped on the block by the rear head on the transmission side. Just run the VIN on the block (that is if it's a US Spec engine) and see if it comes from a TT :)

As for comp numbers... that's going to be next to impossible without using a starter. You'll need to spin the engine at about 400 rpms to get decent numbers.

I have the pic below of the engine. Looks like there is a hole for a dowel, but appears that the dowel is missing. Would the N/A crank have the hole for it?

I'll stop by my garage tonight and take a closer look at the other things you listed. Thanks!

http://i14.photobucket.com/albums/a325/fst3000gt_vr4/For%20sale/engine/IMG00675.jpg

gs1000kat
01-12-2011, 06:59 PM
The only thing I could find was a stamp behind the front head. From what I could tell it looked like YH 7156

gs1000kat
01-13-2011, 04:55 PM
The only thing I could find was a stamp behind the front head. From what I could tell it looked like YH 7156

Anyone know what this might mean? If anything?

gs1000kat
01-14-2011, 12:08 AM
The markings to look for ar 3N or 3A for N/A heads, 3T or 3T2 for TT heads.

Steve

The heads aren't the problem. The markings on the heads told me they are N/A(3N). That is what lead me to question whether the shortblock is TT or N/A. I don't know if just the headsa were swapped, or the whole engine. Either way, they used the turbo manifolds and turbos, but used the intake hose(from MAF to TB) of an N/A. I'll pull the pan one of these days. I just don't have a way to lift it right now.

gs1000kat
01-18-2011, 08:49 AM
I pulled the pan off this weekend and took a few pics. I'm not seeing anything that looks like squriters, but I'm not real sure what I'm looking for. Pretty sure it's an N/A. Which pisses me off, BTW.

Can someone take a look and verify?

http://i14.photobucket.com/albums/a325/fst3000gt_vr4/2011-01-15_15-54-25_970.jpg
http://i14.photobucket.com/albums/a325/fst3000gt_vr4/2011-01-15_15-54-13_825.jpg
http://i14.photobucket.com/albums/a325/fst3000gt_vr4/2011-01-15_15-53-43_674.jpg
http://i14.photobucket.com/albums/a325/fst3000gt_vr4/2011-01-15_15-53-28_113.jpg
http://i14.photobucket.com/albums/a325/fst3000gt_vr4/2011-01-15_15-53-16_714.jpg
http://i14.photobucket.com/albums/a325/fst3000gt_vr4/2011-01-15_15-53-01_853.jpg
http://i14.photobucket.com/albums/a325/fst3000gt_vr4/2011-01-15_15-52-37_8.jpg
http://i14.photobucket.com/albums/a325/fst3000gt_vr4/2011-01-15_15-52-20_892.jpg
http://i14.photobucket.com/albums/a325/fst3000gt_vr4/2011-01-15_15-51-56_204.jpg

Hans@GZP
01-18-2011, 04:01 PM
That's an NA block

gs1000kat
01-18-2011, 06:00 PM
Thought so. That really sucks.

I do appreciate your help though. Man, I was trying to sell this as a TT engine too. that would have been embarassing.