Was the block decked significantly... how far were the slugs in the hole? Good TQ numbers down low where it will spend most of it's life.
360 on the dyno
- Thread starter Babyblue66
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Was the block decked significantly... how far were the slugs in the hole? Good TQ numbers down low where it will spend most of it's life.
Post is very encouraging as I'm hoping to match those TQ numbers down low, my heap spends most of it's time booting around town or on the highway. I don't wind it up to more than 5k rpm very often... no need. Rev limiter is set to 5500. So max HP not a concern for me.
I'm up at 5k ft. elevation and it's possible I might hit it with EFI. Getting and keeping the carb dialed in can be a chore. Seeing the diff between the 2 carbs is very helpful. I have a 750 DP I pulled off my 390 I was thinking of tossing on to see if it made a difference. Not going to bother now. OP just saved me some tuning time.
I'm picking my ride up from the transmission shop on Monday, 727 was bleeding. My 360LA has the midler 268H cam (.450~.450) and less duration @.050 to boot. Will be replacing the original cast heads with a set of Promaxx 63cc closed chamber, 1.6 ratio Harland Sharps rockers (will add .030 lift)and an Air Gap intake topped with a 625 Holley vac. sec. carb. CR should be just under or at 9:1 with a stock thickness gasket.
If I can come close to the numbers in the OP's build I'll be very happy.
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Post is very encouraging as I'm hoping to match those TQ numbers down low, my heap spends most of it's time booting around town or on the highway. I don't wind it up to more than 5k rpm very often... no need. Rev limiter is set to 5500. So max HP not a concern for me.
I'm up at 5k ft. elevation and it's possible I might hit it with EFI. Getting and keeping the carb dialed in can be a chore. Seeing the diff between the 2 carbs is very helpful. I have a 750 DP I pulled off my 390 I was thinking of tossing on to see if it made a difference. Not going to bother now. OP just saved me some tuning time.
I'm picking my ride up from the transmission shop on Monday, 727 was bleeding. My 360LA has the midler 268H cam (.450~.450) and less duration @.050 to boot. Will be replacing the original cast heads with a set of Speedmaster 63cc closed chamber, 1.6 ratio Harland Sharps rockers (will add .030 lift)and an Air Gap intake topped with a 625 Holley vac. sec. carb. CR should be just under or at 9:1 with a stock thickness gasket.
View attachment 1715915054
If I can come close to the numbers in the OP's build I'll be very happy.
The engine I posted was done on the dyno at about 5300.
Nice.. IIRC Vegas is about 2k so not as bad.
Babyblue66
Cool dude
The block was not decked at all. The pistons were .050 in the hole. 10cc 4 valve reliefs. Heads cc'd surprisingly low at 67cc I believe. Stock early 1971 360 heads.
Dan the man
Well-Known Member
How was the block deck height? By photo looks like deck surface didn't have to be machined.
This photo of the Silver 360 is a stock deck height, with .030 over stock style pistons.
"Stock" seems to be a relative term with 360 LA blocks.... I've read of measurements on untouched blocks from .050 to well over .100.
Dan the man
Well-Known Member
I noticed that there isn't much activity going on, no new questions and no comments on anything."Stock" seems to be a relative term with 360 LA blocks.... I've read of measurements on untouched blocks from .050 to well over .100.
Stock 360 Truck Pistons
Notice the heavy duty wrist pin support castings with the large oil holes to provide lubrication to the pressed on wrist pins.
Notice the heavy duty wrist pin support castings with the large oil holes to provide lubrication to the pressed on wrist pins.
I've always liked the factory original cast pistons. Very heavy duty. They will take a lot more abuse than they are given credit for. Especially "those".
If folks want to squeeze a little more compression out of the stock 360s, can try the thin .028 ths Mr. Gasket 318 head gaskets that will also fit the 360s.
Thinner and smaller circumference at the bore equals a little more compression. As compared To the Stock replacement Felpros at .045 ths.
Stated good to 11:1 compression.
Thinner and smaller circumference at the bore equals a little more compression. As compared To the Stock replacement Felpros at .045 ths.
Stated good to 11:1 compression.
Are the stock pistons dished?
Yes stock pistons are dished. 1976 360 here out of a '76 W200 truck.
Believe it is an 8.0 - 8.5:1 compression ratio piston engine.
Thanks for confirming, sounds about right on the CR from what I have read. Got my ride back from the trans shop yesterday. Will take it for a shakedown up to Lake Tahoe this afternoon to ensure the new converter is not building too much heat like the previous unit.
Will likely be tearing my 360 down this weekend. Biggest anxiety point is the deck height and whether or not I'll have any valve clearance issues using the 1.6 ratio rockers I picked up. These posts are very helpful... thx!
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