Help me find the umph in my 360

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Dale Davies said:
That is one solution. The 0.110" deck height is a concern to me. Are your pistons press fit pins or full floating? You could also probably get 0.050" milled off the block decks which would also help. Yes, I know that requires pulling the engine apart. At this point with new heads and cam, the cam can be degree'd and valve to piston clearance verified. You might get away with a very light hone in the cylinders and reuse the rings.
If the pistins are floating pin design, you might be able to find pistons with a larger CD, like +0.100" to raise static compression without milling the block or/and heads. Remember that over "X" amount milled off the heads and/or block on a V engine requires milling the intake manifold to align correctly. The machine shop will know what is required.
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My pistons are pressed
 
dustyaman said:
So fresh build on another 360 engine. I sold my last one. This one came out of 1986 360 d150 pickup.
Took the whole engine apart and did a full rebuild. Bearings, rings, summit 1798 camshaft, .030 over pistons, speedmaster as cast heads, edelbrock air gap intake, 1905 edelbrock carb, Doug's headers, The 727 came out of the same truck. No rebuild it shifts ok for a basic 727 And converter is stock also. It cruises great. With 3.55 gears around 3000 rpm I'm at 50 mph. Now I have timing at 20 degrees initial... it seems to love that the most. I have it on manifold vacuum advance timing. It goes up to 50 by 3000 rpm.
My problem is I feel like it's just sluggish and should have way more power. In drive at full throttle it shifts 1-2 at 3800 which is just getting into the power of the cam. And 2-3 is 4000. Now if I try to manually shift.. at full throttle I will shift it at 4000 but it won't actually shift until 6000. I hate that. Is it the converter that's keeping the power away? Or is it my poorly choice camshaft. I realize that camshaft has a higher rpm power curve. Seems my Transmission is keeping that power away based off its shift points. I need advice to go from here. Oh BTW afr is around 14.0 to 14.5 during cruise and 12.5 at full throttle.
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Sounds like you need a shift kit in your tranny with a correct governor for full power upshifts. If it was me, I would crawl under/ drop the tranny pan and install a kit from a reputable source...that has good step by step instructions.
 
dustyaman said:
My pistons are pressed
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How many miles since it was installed? May be able to pull it apart to mill the block 0.050". In combination with mill the heads will bring the CR up, but the intake would need to be milled to match. Once milled you may be able to pop it back together.
 
Dale Davies said:
How many miles since it was installed? May be able to pull it apart to mill the block 0.050". In combination with mill the heads will bring the CR up, but the intake would need to be milled to match. Once milled you may be able to pop it back together.
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With the new rings probably 50 miles. But I honestly don't want to break the whole engine back apart. I'd rather slap this one back together and drive the car. And buy a separate engine and do a 408 stroker build on the side.
 
ir3333 said:
At 8:1 compression i'd use the comp XE256 and don't go too tall with your rear tires. You'll lose every
parking lot or internet race but won't be able to stop smiling when you drive it or launch it beside a big
block at a stop light.
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I’ve run both the xe256 and the 1798 cam the op is using. At the same compression ratio, but with factory steel heads. Both made great power, but the xe256 was better down low. My converter stalled around 2500 which worked great for both. The 1798 cam wanted 24 degrees initial, and max timing was 38 all in at 3500.
 
I wouldn't dick around trying to mill this and that for compression. I would leave it be. Remember, one full compression point only adds about 3% in power, so the gains there are not worth the cost. Plus, milling a lot from the block and or heads opens up possibly needing custom length pushrods, which is another expense. I simply would not do it in your instance.
 
RustyRatRod said:
I wouldn't dick around trying to mill this and that for compression. I would leave it be. Remember, one full compression point only adds about 3% in power, so the gains there are not worth the cost. Plus, milling a lot from the block and or heads opens up possibly needing custom length pushrods, which is another expense. I simply would not do it in your instance.
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OK SOUNDS GOOD!!
 
OK, looked up Speedmaster heads. They are supposed to have 65 cc chambers. According to Wallace Racing CR calculator, with a 4.03 bore, stock stroke, flat top pistons with no valve reliefs sitting .100 below deck at TDC, .039 head gaskets with a 4.18 diameter opening, your CR is 8.90 to one (half a point higher than a 340 with the same deck height, heads and head gaskets) (also half a point higher than a 360 with factory 72 cc heads, all else the same).

.027 thick Cometic head gaskets with a 4.08 diameter cylinder opening would bring that up a couple of tenths, but they aren't cheap.

Milling the heads .030 will bring the CR up about half a point, and you'll be able to get by without milling the intake side of the heads or changing pushrods. (OEM 360 steel shim head gaskets were something like .020 thick, so milling the heads .030 and running .039 head gaskets will minimally affect geometry.) A .030 mill used to be pretty inexpensive, but I have no idea how much that would cost today.

So unless I seriously miscalculated the CR, what you have isn't great, but it isn't a 7.5 - 8 to one dog, either.
 
65 Cuda 340 said:
OK, looked up Speedmaster heads. They are supposed to have 65 cc chambers. According to Wallace Racing CR calculator, with a 4.03 bore, stock stroke, flat top pistons with no valve reliefs sitting .100 below deck at TDC, .039 head gaskets with a 4.18 diameter opening, your CR is 8.90 to one (half a point higher than a 340 with the same deck height, heads and head gaskets) (also half a point higher than a 360 with factory 72 cc heads, all else the same).

.027 thick Cometic head gaskets with a 4.08 diameter cylinder opening would bring that up a couple of tenths, but they aren't cheap.

Milling the heads .030 will bring the CR up about half a point, and you'll be able to get by without milling the intake side of the heads or changing pushrods. (OEM 360 steel shim head gaskets were something like .020 thick, so milling the heads .030 and running .039 head gaskets will minimally affect geometry.) A .030 mill used to be pretty inexpensive, but I have no idea how much that would cost today.

So unless I seriously miscalculated the CR, what you have isn't great, but it isn't a 7.5 - 8 to one dog, either.
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Thank you for doing all that math
 
dustyaman said:
That's still OK in my book to be honest.
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Remember the Lil Red Express trucks? They were the fastest domestic production vehicles in 78 and 79. 8.5:1 360. .....and those engines were pullin a heavy truck.
 
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RustyRatRod said:
Remember the Lil Red Express trucks? They were the fastest domestic production vehicles in 78 and 79. 8.5:1 360. .....and those engines were pullin a heavy truck.
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How fast were they?
 
dustyaman said:
With the new rings probably 50 miles. But I honestly don't want to break the whole engine back apart. I'd rather slap this one back together and drive the car. And buy a separate engine and do a 408 stroker build on the side.
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Got it. This time do lots of research to get the parts stackup right and the correct cam and heads.
 
just FYI.. the mrgasket .028 head gaskets are $30 each.. not too bad
 
dustyaman said:
Thank you. Probably use the gaskets that summit is giving me for the warranty
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Make SURE they are compatible with aluminum heads. That's a mistake people make sometimes.
 
RustyRatRod said:
Good. Just trying to cover all the bases so you don't have any more failures.
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I appreciate it. Almost ready to pull the engine have most the bolts out except 2 from the engine to trans and motor mounts. And still waiting on parts to start showing up. So just taking my time day by day in this hot and humid heat.
 
Looks like that cam is 'gonna start making power at or above 2000 rpm. Are you going to use the stock
converter?
 
ir3333 said:
Looks like that cam is 'gonna start making power at or above 2000 rpm. Are you going to use the stock
converter?
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Yes I am. I'm going to work with this transmission and converter setup until I pull the trigger on the silversport a41 transmission next year.
 
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