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Krooser said:
Few engines need a line hone much less a line bore. I line bored many engines but the guys that do my stuff today tell me if the crank is easy to turn in the block its a waste of $$$.
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what's the process for getting good clearance if you don't line hone?
it's all on the crank grinder?
 
cookietruck said:
what's the process for getting good clearance if you don't line hone?
it's all on the crank grinder?
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Line honing isn’t how we get the right clearance. Like you said you talk to your crank grinder and he can go high or low side for you. If I need a crank ground .010 to clean it up I’ll tell him to go .011 as I like lots of clearance. You can also buy .001 under or over-bearings.
 
pittsburghracer said:
Line honing isn’t how we get the right clearance. Like you said you talk to your crank grinder and he can go high or low side for you. If I need a crank ground .010 to clean it up I’ll tell him to go .011 as I like lots of clearance. You can also buy .001 under or over-bearings.
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Can you shim bearings?
 
Bodyperson said:
Can you shim bearings?
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Anything is possible, but the thickness and material used could make durability an issue. Nothing stopping you from boring it out larger and turning precision spacers and re-honing, but unless it is a rare and expensive block it isn't likely worth the effort.
 
I forget who it is exactly, though Hughes engines offer them, but someone makes spacers for the larger 360 mains for use with the smaller main cranks. They should take a light hone according to Hughes.

I have never seen shims for the mains. Over and under sized bearings, yes.
 
I’m just going to throw the block,crank,main caps and heads in the garbage and start a new build….
 
67autocross said:
I get it…but every small block I have watched on the dyno pulls to at least 5500 harder with an air gap over a single plane
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The dyno needs to pull at least 600 rpm a second or the AG looks better than it is. 800 rpm a second is even better.
 
Rat Bastid said:
How many RPMs per second did the dyno run at?
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The rpm rate is programed into operation perimeters by the dyno operator.
It is the rate of rpm that the dyno allows the engine to accelerate at.
Hope this helps
 
rumblefish360 said:
I forget who it is exactly, though Hughes engines offer them, but someone makes spacers for the larger 360 mains for use with the smaller main cranks. They should take a light hone according to Hughes.

I have never seen shims for the mains. Over and under sized bearings, yes.
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I saw a guy shimming bearings on an old chevy that had babbit built rods , a long long time ago, was doing it because of rattle and oil consumption , and it worked !
 
bob mCcarty said:
I saw a guy shimming bearings on an old chevy that had babbit built rods , a long long time ago, was doing it because of rattle and oil consumption , and it worked !
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.
They used cigarette paper in some cases. My dad told me he had seen thin leather strapping used also.
People were broke back then. 30-40s they used what they had.
 
67autocross said:
Okay…you’ll have to give me some explanation on this
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512 has a good start on the problem. A water brake engine dyno, like every other tool has its issues. If you don’t understand them, you get bad data. The sweep rate is controlling how fast the engine accelerates. Let’s take 300 RPM per second. You’d be hard pressed to find an engine that will RPM that slow, especially in low gear. So the dyno is now holding the engine back from what it actually does in its normal operation. I just heard Darin Morgan say in a webinar that a Pro Stock engine will RPM at 1600 RPM per second in low gear. If you test that engine at 300 RPM per second, the data will have flaws. I don’t know how the Pro Stock teams test on the dyno or how they evaluate the data if they are using slower sweep rates, but they do it. I do know of at least 3 teams that at one time had an inertia dyno that allows the engine to RPM at whatever rate it does in operation. In fact, there was a report done comparing the Revolution inertia dyno against a water brake dyno. I recall the test being 6 or 8 different intake manifolds for a circle track application. The upshot was both dyno’s gave conflicting data. What looked good on the water brake looked bad on the inertia dyno and what was good on the inertia dyno looked bad on the water brake. After a ton of dyno pulls on each intake on each dyno, they took the car to the track to test them. As I expected, the manifolds that looked the best on the water brake dyno were the slowest in the car, and the manifolds that looked the best on the inertia dyno were the best in the car. How could that be? It’s because the water brake dyno controlled the RPM that the engine accelerated. The inertia dyno allowed the engine to RPM at its natural acceleration rate. So from what I see, if you slow down the engine’s acceleration rate you will get higher horsepower numbers than if you run the test at a higher acceleration rate. In other words, if you run a test at 300 RPM per second and then test that same engine at 600 RPM per second, the 600 RPM per second tests will show LOWER horsepower numbers. I also believe that at slower acceleration rates you see things like a single plane intake manifold lose power to a dual plane, when in reality the single plane, if tested at a higher acceleration rate will should a totally different result, with the result being the single plane is just as good or better than the dual plane everywhere. And that should translate to the same result in the car. Unless you have the chassis not matched to the engine. Like not enough gear and/or converter. When I was 15 years old I was told by a guy who I had a ton of respect for and who had earned that respect with his on track performance (and his street stuff too) that the water brake dyno didn’t measure the ability of the engine to RPM. And he’s not wrong. That doesn’t mean the dyno isn’t a useful tool. You have to recognize what it does well and and what it doesn’t do. Guys who like a big number on the dyno will test at 300 RPM per second. Guys who want more factual data will speed up the acceleration rate and live with the data.
 
Rat Bastid said:
512 has a good start on the problem. A water brake engine dyno, like every other tool has its issues. If you don’t understand them, you get bad data. The sweep rate is controlling how fast the engine accelerates. Let’s take 300 RPM per second. You’d be hard pressed to find an engine that will RPM that slow, especially in low gear. So the dyno is now holding the engine back from what it actually does in its normal operation. I just heard Darin Morgan say in a webinar that a Pro Stock engine will RPM at 1600 RPM per second in low gear. If you test that engine at 300 RPM per second, the data will have flaws. I don’t know how the Pro Stock teams test on the dyno or how they evaluate the data if they are using slower sweep rates, but they do it. I do know of at least 3 teams that at one time had an inertia dyno that allows the engine to RPM at whatever rate it does in operation. In fact, there was a report done comparing the Revolution inertia dyno against a water brake dyno. I recall the test being 6 or 8 different intake manifolds for a circle track application. The upshot was both dyno’s gave conflicting data. What looked good on the water brake looked bad on the inertia dyno and what was good on the inertia dyno looked bad on the water brake. After a ton of dyno pulls on each intake on each dyno, they took the car to the track to test them. As I expected, the manifolds that looked the best on the water brake dyno were the slowest in the car, and the manifolds that looked the best on the inertia dyno were the best in the car. How could that be? It’s because the water brake dyno controlled the RPM that the engine accelerated. The inertia dyno allowed the engine to RPM at its natural acceleration rate. So from what I see, if you slow down the engine’s acceleration rate you will get higher horsepower numbers than if you run the test at a higher acceleration rate. In other words, if you run a test at 300 RPM per second and then test that same engine at 600 RPM per second, the 600 RPM per second tests will show LOWER horsepower numbers. I also believe that at slower acceleration rates you see things like a single plane intake manifold lose power to a dual plane, when in reality the single plane, if tested at a higher acceleration rate will should a totally different result, with the result being the single plane is just as good or better than the dual plane everywhere. And that should translate to the same result in the car. Unless you have the chassis not matched to the engine. Like not enough gear and/or converter. When I was 15 years old I was told by a guy who I had a ton of respect for and who had earned that respect with his on track performance (and his street stuff too) that the water brake dyno didn’t measure the ability of the engine to RPM. And he’s not wrong. That doesn’t mean the dyno isn’t a useful tool. You have to recognize what it does well and and what it doesn’t do. Guys who like a big number on the dyno will test at 300 RPM per second. Guys who want more factual data will speed up the acceleration rate and live with the data.
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Another reason for lower numbers when sweeping at a faster rate is inertia. Unless this is corrected for somehow by the dyno. I understand that if both manifolds are compared at the same rate this does not apply.
 
92b said:
Another reason for lower numbers when sweeping at a faster rate is inertia. Unless this is corrected for somehow by the dyno. I understand that if both manifolds are compared at the same rate this does not apply.
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That is true. Slowing down the acceleration rate negates (to an extent) inertia. In the car you will see that inertia. That’s why you have to set up your dyno testing to duplicate as close as possible what happens in the car.
 
Rat Bastid said:
That is true. Slowing down the acceleration rate negates (to an extent) inertia. In the car you will see that inertia. That’s why you have to set up your dyno testing to duplicate as close as possible what happens in the car.
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Just a thought. Would street driven heavier vehicles with lower (numerically) gear ratios and slower acceleration rates like a dual plane over a single plane?
 
92b said:
Just a thought. Would street driven heavier vehicles with lower (numerically) gear ratios and slower acceleration rates like a dual plane over a single plane?
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Yes
 
92b said:
Just a thought. Would street driven heavier vehicles with lower (numerically) gear ratios and slower acceleration rates like a dual plane over a single plane?[/QUOTE

Yes, but would it be slower than 600 rpm per second? I don’t have an answer for that.
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cookietruck said:
any flow numbers on the Promaxx heads yet?
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I don’t have the numbers yet…saying that a few years ago when I was flowing some EQ heads there was a SBM shocker head at the shop…we flowed the it up to 500 and they were close to advertised
 
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