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Engine size change - Convertor question
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DRR Pro
Picture of chasracer
posted
I moved from a 509" BBC to a 555" one. Same engine just opened up the bore and changed the stroke. I left everything else the same save for adding a vacuum pump. Same heads, camshaft, intake, carb and ignition.

I run a 8" convertor with a flash of 6100-6200 & its spragless. How big an effect would the additional cubes have on the convertor? Combination at the moment just seems "off" from what it was before the size change.
 
Posts: 1135 | Location: The problem is not the problem. The problem is your attitude about the problem. Savvy?” ~~ Captain Jack Sparrow ~~ | Registered: August 21, 2000Reply With QuoteReport This Post
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quote:
Originally posted by chasracer:
I moved from a 509" BBC to a 555" one. Same engine just opened up the bore and changed the stroke. I left everything else the same save for adding a vacuum pump. Same heads, camshaft, intake, carb and ignition.

I run a 8" convertor with a flash of 6100-6200 & its spragless. How big an effect would the additional cubes have on the convertor? Combination at the moment just seems "off" from what it was before the size change.


Depends on the increase or decrease in power.

100hp is 400 rpm's of observed stall, as example.
 
Posts: 9398 | Location: Madeira Beach Fl. | Registered: June 12, 2018Reply With QuoteReport This Post
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Picture of The Bozman
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you are probably blowing through the convertor with the added TQ, heads and cam information as well as car information would also be of value.


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Posts: 2497 | Location: Gilmer, Texas | Registered: June 25, 2002Reply With QuoteReport This Post
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Picture of chasracer
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The heads are BB-2X with some pro level porting.

Cam Spec:

@.050 282/294
.427/.420

Gross lift .720/.714
Lobe Sep: 110
Installed at 108 ICL

This message has been edited. Last edited by: chasracer,
 
Posts: 1135 | Location: The problem is not the problem. The problem is your attitude about the problem. Savvy?” ~~ Captain Jack Sparrow ~~ | Registered: August 21, 2000Reply With QuoteReport This Post
DRR Pro
Picture of Goob
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You've run out of cam and cylinder head for those inches, been here, seen this.
NOT to say that a converter change wouldn't help you achieve something.

You need 355cc+ intake runners and .800"-.820" lift to do the 555 justice.


"Despite the high cost of living, it remains popular."
Dave Cook
N375
 
Posts: 1622 | Location: Indy | Registered: November 21, 2008Reply With QuoteReport This Post
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I agree with Bozman, you'll probably blow through that 8 inch given the flash numbers you posted using the 509. I would try that original 8 inch and see how it acts. That cam looks a little short on the lift side for a 555.

It may be time to look at a spragless 9inch.

Bob
 
Posts: 3080 | Location: Lakeside, Ca | Registered: February 15, 2003Reply With QuoteReport This Post
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Picture of SCDIV1
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The 555 will not work well with the same parts.

Heads to small, cam way to small.

More low end torque but it’ll run out of steam as rpm rises.

Just last year I upped my engine from a 565 to a 584

Same heads and cam

The 584 is weaker than the engine as a 565.

Has more torque down low but that’s it...

Same converter is a little bit looser.

I ran a 509 with an 8” converter and went to a 9” when I built the 565

I can recall feeling like I never should have sold the 8” and just tried it behind that 565

I think it would have been just fine
 
Posts: 2733 | Location: Where ever I am, I'm here and it's me | Registered: March 15, 2007Reply With QuoteReport This Post



DRR Sportsman
Picture of Bob Deniker
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I would try it. That's JMO, and I'm sure the resident expert will tell me I'm wrong.
 
Posts: 621 | Location: Latrobe Pa. | Registered: July 30, 2007Reply With QuoteReport This Post
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Listen to the converter, it'll tell you.

Less stall is less power

More stall is more power

RPM and Torque are measurable quantities of engine output

If you think you can go faster and more consistent with a diesel operating at lower rpm, have at it, but it's the opposite of what the tire / chassis wants in the burnout, or on the starting line.
 
Posts: 9398 | Location: Madeira Beach Fl. | Registered: June 12, 2018Reply With QuoteReport This Post
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Picture of chasracer
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Not sure what "try it" means in this context.

But here are the facts, even though I know that the parts are not optimal, I'm not changing cylinder heads, intake, ignition, etc. The 509 ran 4.93-4.94 pretty consistently. If I hadn't messed up the crankshaft, I would still be running it. The 509 launched well and pulled like a beast - I was happy with it so at this point I have basically screwed myself. To be honest, I'm disappointed in the 555 at this point. I'm not in a position to throw a lot at it which is where dial boards and shoe polish come in. I would consider upgrading the roller cam and then going after another convertor. I do have a larger carb that I can put on this deal.

Anyone moved up from a 540-555 and have a good condition roller cam they want to part with?
 
Posts: 1135 | Location: The problem is not the problem. The problem is your attitude about the problem. Savvy?” ~~ Captain Jack Sparrow ~~ | Registered: August 21, 2000Reply With QuoteReport This Post
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I ran an 8" behind my 485, 532 and my current set up which is a 555. I ran the same convertor behind both the 532 and 555 with the same exact internals besides crankshaft and gained about 200 in stall.
 
Posts: 27 | Location: Pen Argyl, PA | Registered: March 01, 2011Reply With QuoteReport This Post
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Picture of chasracer
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quote:
Originally posted by JakeW143:
I ran an 8" behind my 485, 532 and my current set up which is a 555. I ran the same convertor behind both the 532 and 555 with the same exact internals besides crankshaft and gained about 200 in stall.

sent PM
 
Posts: 1135 | Location: The problem is not the problem. The problem is your attitude about the problem. Savvy?” ~~ Captain Jack Sparrow ~~ | Registered: August 21, 2000Reply With QuoteReport This Post
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Picture of Goob
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quote:
Originally posted by chasracer:
Not sure what "try it" means in this context.

But here are the facts, even though I know that the parts are not optimal, I'm not changing cylinder heads, intake, ignition, etc. The 509 ran 4.93-4.94 pretty consistently. If I hadn't messed up the crankshaft, I would still be running it. The 509 launched well and pulled like a beast - I was happy with it so at this point I have basically screwed myself. To be honest, I'm disappointed in the 555 at this point. I'm not in a position to throw a lot at it which is where dial boards and shoe polish come in. I would consider upgrading the roller cam and then going after another convertor. I do have a larger carb that I can put on this deal.

Anyone moved up from a 540-555 and have a good condition roller cam they want to part with?


If you can find one used, it's hard to beat the Reher-Morrison 555 Bracket cam, it's a little over .800" lift and easy on parts, or Bullet can do a very similar grind.


"Despite the high cost of living, it remains popular."
Dave Cook
N375
 
Posts: 1622 | Location: Indy | Registered: November 21, 2008Reply With QuoteReport This Post
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Goob's suggestion is a good one.

R-M 420-116 is an Erson cam, makes good power, does not require huge spring pressure and does not break parts

I've used that cam and have one on the shelf
 
Posts: 2733 | Location: Where ever I am, I'm here and it's me | Registered: March 15, 2007Reply With QuoteReport This Post



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Thanks for the cam suggestions. I appreciate your help!
 
Posts: 1135 | Location: The problem is not the problem. The problem is your attitude about the problem. Savvy?” ~~ Captain Jack Sparrow ~~ | Registered: August 21, 2000Reply With QuoteReport This Post
DRR Sportsman
Picture of Bob Deniker
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[QUOTE]Originally posted by chasracer:
Not sure what "try it" means in this context.

Try it means put it in and try it. At least you'll know what you need to do, if any adjustments need made.
 
Posts: 621 | Location: Latrobe Pa. | Registered: July 30, 2007Reply With QuoteReport This Post
DRR Pro
Picture of chasracer
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quote:
Originally posted by Bob Deniker:
[QUOTE]Originally posted by chasracer:
Not sure what "try it" means in this context.

Try it means put it in and try it. At least you'll know what you need to do, if any adjustments need made.


I think we're having a comm problem here.

I do not know what you are suggesting I put in the engine and try.
 
Posts: 1135 | Location: The problem is not the problem. The problem is your attitude about the problem. Savvy?” ~~ Captain Jack Sparrow ~~ | Registered: August 21, 2000Reply With QuoteReport This Post
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Your cam is not that bad, I basically used the same pieces in the early 2000's and they always made between 850-900 horsepower. You need to look at others things.


Duane Allen
 
Posts: 29 | Location: Sandston VA | Registered: December 14, 2006Reply With QuoteReport This Post
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Originally posted by Duane1791:
Your cam is not that bad, I basically used the same pieces in the early 2000's and they always made between 850-900 horsepower. You need to look at others things.


After looking at it, I agree. Put

a 1.8 ratio rocker on the intake.

Opel core 8" converter will be fine 410-430 gear.




@.050 282/294
.427/.420

Gross lift .720 - .768/.714
Lobe Sep: 110
Installed at 108 ICL
 
Posts: 9398 | Location: Madeira Beach Fl. | Registered: June 12, 2018Reply With QuoteReport This Post
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Picture of chasracer
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I think changing the cam might be cheaper. Not exactly sure how much 8 Jesel 1.8 rockers cost today.

Already run a 4.10 gear.

The heads are the BB-2X CNC which are 341 port volume and supposedly 365+ area at .700 lift. They have the 2.30 intake valves.

Does anyone know a cam part number close to the R-M cam?
 
Posts: 1135 | Location: The problem is not the problem. The problem is your attitude about the problem. Savvy?” ~~ Captain Jack Sparrow ~~ | Registered: August 21, 2000Reply With QuoteReport This Post
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