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I'm new here and need advice with my 505

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11:09 AM
Joined
Aug 29, 2019
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Location
Howell New Jersey
Recently i purchased a 505 that has only minimal use . It has ported and milled 906 heads, hyd roller cam by comp cams model 23-712-9 , eagle forged rods 7.1 inch and forged crank. And a brand I can't find much info about pistons Auto Tec # 7859 . I believe they are -39 dish 4.350" deck clearance measures .012 on each side and the deck is 10.718 on each side .
I have been impressed with this website and the wealth of knowledge many members here have .I am looking to do some work to get it to the 600hp range . And I am wondering if a trick flow top end kit would get me there and if it sounds like it would fit or if I need to change the pistons either way because I would like to be in the 10.5-11 compression range . I'm not sure we're I am at now but I'm guessing pretty low with 906 heads .095 milled ? Is there pistons I can buy that are forged I can just hone and install . What advice would you have to get some power with a $ 7000 budget. Thank you for your help and time .kevin
 
Can’t help you but I can welcome you to FBBO from SoCal. Someone will jump on that has experience that you seek.
 
Welcome & good luck with your build! Answers to your question(s) will show up...
 
Welcome from the show me state!!
 
You might want to try doing more research on your pistons.. Typically 505 with a 4.25 throw & 7.1 rods gets a dish of 17 to 27cc's..

Don't know how you got the idea 39cc dish pistons are gonna put you in the 10.5-1 range..

Trick flow 240 & 270 both have 78cc chambers, using a 27cc dish that puts you at 9.9 if you really have a 39cc dish which I doubt you'd be roughly 9-1

FWIW with no other info Trick Flows would be a huge step in the right direction...
 
You might want to try doing more research on your pistons.. Typically 505 with a 4.25 throw & 7.1 rods gets a dish of 17 to 27cc's..

Don't know how you got the idea 39cc dish pistons are gonna put you in the 10.5-1 range..

Trick flow 240 & 270 both have 78cc chambers, using a 27cc dish that puts you at 9.9 if you really have a 39cc dish which I doubt you'd be roughly 9-1

FWIW with no other info Trick Flows would be a huge step in the right direction...
I may have stated that wrong I would like to get up to 10.5-1 or 11 to 1 . .I guess a piston swap is necessary I don't think it's smart running that low of compression with expensive heads
. I just wasn't sure what parts would be suggested and who is a reputable dealer I could get parts from . Is it even ok to just hone and change pistons and rod pins and bearings if the block has 2000 miles on it . Should I buy rods also etc.. I appreciate the advice !!
 
I may have stated that wrong I would like to get up to 10.5-1 or 11 to 1 . .I guess a piston swap is necessary I don't think it's smart running that low of compression with expensive heads
. I just wasn't sure what parts would be suggested and who is a reputable dealer I could get parts from . Is it even ok to just hone and change pistons and rod pins and bearings if the block has 2000 miles on it . Should I buy rods also etc.. I appreciate the advice !!

I would contact Race-tec to see it they have an further info on your pistons...

Do you know who built the engine? Do they have an info?

Personally before taking this engine apart to change the build I'd consider either selling it or sidelining it for another project & build a different block.. 44o blocks aren't hard to find & there's likely nothing special about the one you have...

If you can get what you want with a head swap sure, but tear into a running short block that has no issues? Not a good choice IMO..
 
That actually sounds like experience talking!! I am not sure of who built it but I have all of the machine shop data and the receipt and build specs . unfortunately the shops name wasn't on the sheet. .. but I may be able to dig through the binders of papers that came with the car to find out. .
I just am not sure if it is a can of worms I will open. Or if I should just go for it . I truthfully wouldn't mind selling it or trading it for a rotating assembly.. it was built for reliable street use and I'm looking for a little more hp then the 450 it made on the Dyno....
 
Compression increase would not be my first point of issue to get that engine to make more power. You need to feed it and that is heads. You would be surprised at the HP from a 9-9.5:1 engine that has a good head/camshaft/induction on it.

Unless those 906's are ported and flow really good numbers, it's the choke point in the assembly.. The cam is probably not large enough to get 600hp as well.
 
Compression increase would not be my first point of issue to get that engine to make more power. You need to feed it and that is heads. You would be surprised at the HP from a 9-9.5:1 engine that has a good head/camshaft/induction on it.

Unless those 906's are ported and flow really good numbers, it's the choke point in the assembly.. The cam is probably not large enough to get 600hp as well.
That's what I'm curious about . I have always heard high compression is were it's at. I was looking at purchasing the trick flow 240 top end kit with cam included or even getting the brodix b1-bb heads and intake and cam because the have a small combustion chamber . But I wasn't sure if it would be even worth it . With 39 dish pistons ...is there any other advice or tricks? Maybe I can weld a few nickels to the piston tops to boost the comp... Lol just joking
 
Lobe separation 110.0
Intake centerline 106.0
Duration intake 286. Exhaust duration294
intake @.050 lift 236. Exh @.050 242
Intake valve lift .544. Exh valve lift .541
Intake lobe lift .363. Exh lobe lift.361
 
JMO, boosting compression is not going to make the engine have a ton more power. Going from 9.0 to 10.5 isn't going to provide even 30hp is my guess. It's the wrong spot to look. Low compression would make it more pump gas/swill friendly too.

The trick flows are good heads and work well. On a 505, I'd put the 270's on it with a bigger cam and an induction system to feed it and let it eat. Pistons would be the last thing I'd be concerned with.
 
Is the engine in a car or on a stand? Are the heads on or off? Personally I'd CC those piston dishes just to confirm what they are...

I agree with Rob, flow is your biggest choke point... Increased compression helps but without flow your not going to make big power & with flow you'll likely make enough that you won't feel the need to chase the extra power higher compression will provide.... A stout 505 that breathes well even at 9-1 is gonna make gobs of torque... Personally I'd leave that cam alone till I'm convinced heads alone don't give me what I want...

550 HP in a street car is scary fast to scare most people, 600 isn't worth completely scrapping what you have...
 
The build sheet said I currently have 9.5 cr with slightly milled 906 heads . I would guess the 270 trick flows would do the breathing trick and boost it too . I am not sure of the specs but they have to be a way better solution ...
 
Is the engine in a car or on a stand? Are the heads on or off? Personally I'd CC those piston dishes just to confirm what they are...

I agree with Rob, flow is your biggest choke point... Increased compression helps but without flow your not going to make big power & with flow you'll likely make enough that you won't feel the need to chase the extra power higher compression will provide.... A stout 505 that breathes well even at 9-1 is gonna make gobs of torque... Personally I'd leave that cam alone till I'm convinced heads alone don't give me what I want...

550 HP in a street car is scary fast to scare most people, 600 isn't worth completely scrapping what you have...
The car is complete with the motor in it . But I am planning to start purchasing parts within the month and i was going to pull the motor. If I can just do a top-end switch I could probably keep it in the car and save the headache of removal
 
The car is complete with the motor in it . But I am planning to start purchasing parts within the month and i was going to pull the motor. If I can just do a top-end switch I could probably keep it in the car and save the headache of removal
And again thank you for your advice I really appreciate all of the good info
 
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