Babyblue66
Cool dude
Anyone know what the aprox. compression would be of a 1984 truck 360? Can get one with 77,000 miles for 200 bucks. Maybe a cheap engine for my 65 Barracuda. Says it ran real good.
360 compression question
- Thread starter Babyblue66
- Start date
-
moper
Well-Known Member
Whenactually measured and calculated, it's closer to 7.8:1. But, if it runs well, don't worry about it.
I also found what Moper said to be true. The actual speced and measured ratio is way lower than what is advertised. That 8.5-1 that 70aar said is what was advertised, but that's not the actual.
I also say do not worry about the actual ratio. If it runs well, and doesn't burn up or leak the oil, your in good shape. You can boost performance with closed chambered heads (Mill the stock ones .060 or what ever it needs) and a cam change.
Even the stock 4bbl. intake and carbs are decent performers.
I also say do not worry about the actual ratio. If it runs well, and doesn't burn up or leak the oil, your in good shape. You can boost performance with closed chambered heads (Mill the stock ones .060 or what ever it needs) and a cam change.
Even the stock 4bbl. intake and carbs are decent performers.
yeah..and i was going to write unless you take it apart and measure the head cc and how far the pistons are down in the bore ...u dont really know...but i gave the short answer...LOL
Babyblue66
Cool dude
If I get it I will pull the heads and cc them. Since i work at a shop I'd give it a valve job too.
I have a cam I used in my 273 for a few hundred miles. Just a Crane 270, 216 @ .050 with .454 lift. Also have a 340 spread bore intake and a Performer. And several carbs, including a nice working Thermoquad I rebuilt from a 73 440. It would be nice runner. Eventually I'd like to do a performance rebuild, but this would be way cheaper and make a good driver for the up coming summer. Just have to go pick it up soon.
I have a cam I used in my 273 for a few hundred miles. Just a Crane 270, 216 @ .050 with .454 lift. Also have a 340 spread bore intake and a Performer. And several carbs, including a nice working Thermoquad I rebuilt from a 73 440. It would be nice runner. Eventually I'd like to do a performance rebuild, but this would be way cheaper and make a good driver for the up coming summer. Just have to go pick it up soon.
Sounds good. I'd up the cam 10+ degrees myself and use the T-Q carb and intake. Space the carb up alittle. With a preped head, it will perform well.
Babyblue66
Cool dude
I'd up the cam a little too, but I don't want to buy another one right now. I have a new solid 238-248 @ .050 .480, .500, but thats too much for this combo. Think I'll just use the smallish one, should keep decent cylinder pressure.
I also have a new comp 224 @ .050 solid with 468 lift, not much difference than the Crane I mentioned earlier, considering some duration and lift is lost with valve lash.
Well it has 8 more degrees! (@.050) And would work reall well with the factory TQ set up. No doubt. Do you have the correct pushrods and arms for it? I'd go for it.
Babyblue66
Cool dude
I do from a 273, but I from what I've learned and my boss who has been building engines for 20 years says you lose up to 8-10 degrees of duration with valve lash. It makes sense, he builds a lot of solid cam motors and they do run as though they have less duration than whats listed.
I suspect there would be some improvement as solid cams have higher rates of lift.
If it's speced @ .050 to be *** amount, then that what it'll be, not *8 less than what is speced. Then it's still 8* more than the Hyd. Do yourself a favor and mic the valve tip or retainer and let me know what you find on lift with the lash set.
Babyblue66
Cool dude
Maybe I'm thinking of advertised duration loss. Or maybe I don't know what the hell I'm talking about
Babyblue66
Cool dude
Well got the 360, pulled the head to find some dip **** let water get into no.2 cylinder and it pitted real bad, the others look great. So now I'm 200 bucks poorer and still need an engine :angry7:
'64 Cuda
Well-Known Member
Don't say that! I'm going to pick up a used 360 this weekend. Hopefully no dip **** was around this motor. The guy said this one was a good runner, but don't they always say that? I'm keeping my fingers crossed. Maybe I should knock on wood too!
Babyblue66
Cool dude
If its an original unopened engine, I would recommend changing the valve seals if not a valve job. Mine has 77,000 and the seals are hardened and falling apart.
Maybe I'm thinking of advertised duration loss. Or maybe I don't know what the hell I'm talking about
He he he, it's the way solids act. There duration @ .050 is no different than a rollers (Hyd. or mech.) or a Hyd. cam.
The advertised numbers are different even when listed the same. Not to mention the actual lift rates.
'64 Cuda
Well-Known Member
It's got 140,000 miles on it. I plan to go through the whole thing.
swing69
I’m just an old guy……
the stock 360 will be 7.8:1. I have a 79 apart now, same thing. heads are OK to use as is, but the stock piston is where the compression loss is. Stockers are pretty far down in the hole AND are dished. My 79 is from a Maxivan.
I have a set of Arias forged pistons (+.030) for it. they are flat top with valve reliefs. the pin to top dist. is ~ .060 more! Arias told me the pistons should be ~ 9:1 with stock crank and heads.
Thats the route I'm gonna go. Clean/bore +030, use forged pistons....do a valve job and run it!
I have a set of Arias forged pistons (+.030) for it. they are flat top with valve reliefs. the pin to top dist. is ~ .060 more! Arias told me the pistons should be ~ 9:1 with stock crank and heads.
Thats the route I'm gonna go. Clean/bore +030, use forged pistons....do a valve job and run it!
-
Similar threads
