Inliners International Forums General Discussion Engines Do I need a new engine???

I have a 230 in my 1969 Nova. I did a compression test on it, but I did it when the engine was cold. The results were:
1-115
2-130
3-125
4-132
5-125
6-116
Is the compression this low becuase the engine was cold or does that not really matter? Are these numbers low enough to recquire a new engine? My engine does not run "bad" but it is not as powerful as many people claim theirs are. Others say their six with a four barrel and headers are fast, but my car is not "fast".

ive heard that u can have up to 20 psi difference max before u really need to change anything but sometimes what the book says sucks but ive got about the same variation of psi and im running strong, im even leaking a bit at the gasket. but it doesnt effect too much. i used some of that thick oil additive to seal small gaps though after i checked the compression so i dont know how it is now, but i did notice a big power jump from stock ignition to high performance ignition and coil. maybe the engine just isnt tuned up right, ive tuned my engine a few times and got different results every time, right now i have the most power ive had in a while but im sacrificing a small bit af fuel to do it.
and a six with a 4bbl and header is fast unless your comparing to some modern plastic toy car that doesnt need a big engine to go fast.

For the test to be accurate the engine must be tested hot. A good engine will give poor results when cold. So try again & see.

Good luck, John M., #3370.

Novaboy,

It takes a LOT] more than just headers and a 4 barrel to make an old inline 6 go fast. Especially a 230 CI.

To achieve a truly proportional increase in power you have to increase your compression and raise the HP RPM range. And these changes will be largely wasted if there isn't significant headwork along with the other changes. Because the stock 230/250/292 straight six head design sucks from a performance point of view, with the large boss in the center of the head.

To give you a point of reference regarding power, I went from a bone stock 230 to a 292 with some hop up goodies (larger cam, 4 barrel, long tube headers, .060 overbore, etc.). And there isn't a much improvement at all over the 230 through the first 2500 rpm. All in all I probably added 40 horsepower (maybe) over a stock 292.

-magic mike-

A warm/hot motor will give a much better compression reading over a cold motor. There are mayn things the can make a car feel fast. Lowering it, Nosie( loud exhaust) a simple trany swap. ex. I had a stock 250 with headers & offey
intake & a 4b carb.(stock 3:08 gear) it ran a mid to high 18s Made a tranny swap to a 3speed sag. and car ran mid 17s ( same Gears) SO is this fast hum to some maybe?? But then I rebuilt the motor
Cam head work same intake & stock 3:08 gears and a M20 car then ran 15.15 in 3rd gear. Made other gear changes (final gear set 5:13) still the same build up after 17 yrs car ran a best of 14.4s So again is this Fast? From a mid. to upper 18s Yes But for some this maybe fast But is it fast compaired to a 9 sec car No. Thier are guys that run what is known as a stock class and have to run the 194 that came in there car and some of them run the 14s But they are still pretty much far from stock/ factory specks. And thing can be built to run fast. But bigger the cubes Bigger the Hp. But everything has to be looked at Head work,Choice of Cam, Intake system, Headers, Gearing, Tranny work or in my chase how well/strong the clutch is. All of this adds up to Hp or speed depending how you want to look at all of this. Hope this helps.}[oooooo]

Ps if you can get or find either the 250 or 292 go for it If not well The 230 can and will make more power with all the right work/ up grades But not like it would if you had either the 250, 292 with the same Up grades. The 250 will bolt right in place or the 230. The 292 will need some mods ( in the motor mounting area) because the 292 mounts are different then that of the 194,230,250.
Other then that it will bolt up to the same tranny .

I'm going to jump in here a little late. The Trueslayer is right factory says 130 pounds per cylinder with a maximum variation of 20 psi. According to the factory you are within spec.. He's also correct in can't believe the book. You don't know what has been done to the engine in last 25 years. Compression is not the only criteria of whether the engine needs to replaced. What's your oil pressure??? I have a mechanical oil pressure gauage with a pipe fitting direct from the case, think I picked it up in a motorcycle shop, that I use. Pull the idiot sender and install an oil guage if only temporary. If you have 25-30 pounds at idle with the engine warm, then think about going fast. Anything less than 20 start looking for that replacement.
The compression is OK, if the oil pressure is good, there are things you can do to make it perform better.


Larry
68 C20 327 daily driver
63 C20 292 Camper truck
65 C10 ? Custom Cab AC,PB,PS,$flasher

im running straight pipe with only a cherry bomb and the noise does make it seem faster, but i have a rebuilt supposedly stock 250 and i'm running high 18's, 0-60 in 13.1 and i have stock exhaust manifold, single bbl carb and stock everything except i picked up a used tranny that i dont know much about but my buddy said he saw the torque converter brand in a racing mag. what u did with the header and intake and 4 bbl was add 25% real at the wheel HP (source is from Clifford Performance)thats still a fair bit i had thought.

thetrueslayer what is your over all speed and what car is this in. And i'm guess this is 1/4 mile times? }[oooooo]

Twisted6:

this is in a merc. monarch that weighs 3250 lbs
and my 1/4 mile time was roughly done using a premade 1/4 mile on some road out of town, and i was with my buddy who was using my cd player as a timer, i didnt look at the time but my speed was at about 70-75 mph when i got to the line. and i think my motor is stock, i bought it off a mechanic who rebuilt it and he didnt say anything special about it so i figgure its stock. if this sound a little fast for a stock car of this weight then tell me and ill be sure to take a peek at it in the near future to see if it is indeed stock.

Now for the weight that sounds about right. and I'm guessing that a 3speed At tranny 0-60 in 13.1 and Your saying high 18s Your pretty close on the call Because once it hits that 3rd gear Your pretty much out of the stocks power band for a 1/4 track run. Yeah the speed mit seem to still be climbing But not as if you were in sec. or first. }[oooooo]
Ps sometime hit a track if you can and see how close that your road test realy was.

will do thanks for the info