Best way to proceed with improving up 427 Windsor street setup

[DAVID GAGNARD]

I'll take a shot at it......

First off I don't think your cold cranking compression numbers are all that bad, cams with a lot of overlap and duration will not show high cranking numbers..and being they are all close together is another good sign.....

A 427 stroker built to making the advertised HP as yours was built to do will have an aggressive cam and will not like to run at low rpms like yours,it will come on in the higher rpm range as yours does......it's the nature of the beast......

Your fuel mileage will depend a lot on how your drive the car,if your easy on the gas pedal you should get better than 9-10 mpg,but if your like most of use and like to get on it and run it up to 4000 to 5000+ rpms shifting,well, 9-10 mpg is all you can expect......

Your low rwhp #'s could also be tied in with your exhaust...I'm not familiar with the type you have,but it has been proven time and time again on here that exhaust/mufflers plays a big role in rwhp, some have reported a proven 100hp loss with certain types of headers/mufflers....
taking off the side pipes/mufflers and running a pull or two without them might tell you a story you will not believe.....

one or two rear wheel dyno pulls is not enough to tune a car,don't know how many pulls you made or what was done,but at least a half day on a rear wheel dyno will get you the most out of your engine....
each engine I have had on a dyno (engine dyno) was the better part of a day..the tuner tried different jettings and different timing settings and overall at least 20 to 30 hp was gained by trying different configurations.....on my last engine,a change of 2 degrees in the timing was good for 12 hp....we went up/down the timing range from 26 total degrees to 34 total at 2 degree increments and there was a 24 hp difference from 30 to 34 degrees....something you would not know unless it was on a dyno...

There are other things besides jetting and timing to take in consideration,air/fuel ratio,volumetric efficiency and a number of other readings to get the most out of what you have......

Unless you go with a "modern" type engine,you will not have a smooth idling,banshee off idle engine, push rod,carbed, stroker motors just don't do that and make 585hp....

You do have a loss of hp somewhere and I think if you can get it figured out and up to where it should be, you'll be more than satisfied with your engine......

good luck with it and keep us posted......

david

[Ace23]

Originally Posted by DAVID GAGNARD

I'll take a shot at it......

First off I don't think your cold cranking compression numbers are all that bad, cams with a lot of overlap and duration will not show high cranking numbers..and being they are all close together is another good sign.....

A 427 stroker built to making the advertised HP as yours was built to do will have an aggressive cam and will not like to run at low rpms like yours,it will come on in the higher rpm range as yours does......it's the nature of the beast......

Your fuel mileage will depend a lot on how your drive the car,if your easy on the gas pedal you should get better than 9-10 mpg,but if your like most of use and like to get on it and run it up to 4000 to 5000+ rpms shifting,well, 9-10 mpg is all you can expect......

Your low rwhp #'s could also be tied in with your exhaust...I'm not familiar with the type you have,but it has been proven time and time again on here that exhaust/mufflers plays a big role in rwhp, some have reported a proven 100hp loss with certain types of headers/mufflers....
taking off the side pipes/mufflers and running a pull or two without them might tell you a story you will not believe.....

one or two rear wheel dyno pulls is not enough to tune a car,don't know how many pulls you made or what was done,but at least a half day on a rear wheel dyno will get you the most out of your engine....
each engine I have had on a dyno (engine dyno) was the better part of a day..the tuner tried different jettings and different timing settings and overall at least 20 to 30 hp was gained by trying different configurations.....on my last engine,a change of 2 degrees in the timing was good for 12 hp....we went up/down the timing range from 26 total degrees to 34 total at 2 degree increments and there was a 24 hp difference from 30 to 34 degrees....something you would not know unless it was on a dyno...

There are other things besides jetting and timing to take in consideration,air/fuel ratio,volumetric efficiency and a number of other readings to get the most out of what you have......

Unless you go with a "modern" type engine,you will not have a smooth idling,banshee off idle engine, push rod,carbed, stroker motors just don't do that and make 585hp....

You do have a loss of hp somewhere and I think if you can get it figured out and up to where it should be, you'll be more than satisfied with your engine......

good luck with it and keep us posted......

david

David
Thanks for your input. When the car was tuned the tuner did exaclty as you described......I would say a good 3-4 hours was spent tweaking the carb and making timing adjustments while on the dyno. I guess I have overlooked the exhaust. I called Firefly and they told me the pipes that were purchased for my car should be 2.5". I guess the only way to tell would be to remove and measure to verify. As you have mentioned there are quite a few stories about the HP gained from removing or swapping exhaust. While I have no reason to doubt the Firefly exhaust is better than the stock exhaust I should still investigate this as a possible issue. Its pretty weird how well the car runs to be down on power. Will keep everyone informed if anything is found that relates to the exhaust. Might need to check the headers and how they mount up to the heads as well. The headers were custom made 2" to fit the Brodix heads back in 2004

[DAVID GAGNARD]

Even with your compression psi being down to what it is,I don't think that would equal to the loss of hp your seeing,just my opinion......

Sounds like your dyno guy tried jetting and timing and got that part optimized to the engine,so taking that out of the picture,it has to be elsewhere......

Not knowing anything about the headers/sidepipes/mufflers other than the diameter,I'm betting there is a big loss there......I'm running 2.5 inch exhaust and 2.5 inch in/out big mufflers on my little 331 stroker and it is in the 400 to 425 hp range.....

Inside those 2.5 inch side pipes are mufflers of some sort ( a lot smaller than 2.5 inches) and I think that is a big "choking" point for a 427 stroker engine......I'm betting taking off the side pipes/mufflers will surprise you....For a 585 hp,427 stroker,I would run nothing smaller than 3.5 side pipes and a free flowing muffler to see optimum power...

Can you post of photo of the side pipes???

David

[Ace23]

Originally Posted by DAVID GAGNARD

Even with your compression psi being down to what it is,I don't think that would equal to the loss of hp your seeing,just my opinion......

Sounds like your dyno guy tried jetting and timing and got that part optimized to the engine,so taking that out of the picture,it has to be elsewhere......

Not knowing anything about the headers/sidepipes/mufflers other than the diameter,I'm betting there is a big loss there......I'm running 2.5 inch exhaust and 2.5 inch in/out big mufflers on my little 331 stroker and it is in the 400 to 425 hp range.....

Inside those 2.5 inch side pipes are mufflers of some sort ( a lot smaller than 2.5 inches) and I think that is a big "choking" point for a 427 stroker engine......I'm betting taking off the side pipes/mufflers will surprise you....For a 585 hp,427 stroker,I would run nothing smaller than 3.5 side pipes and a free flowing muffler to see optimum power...

Can you post of photo of the side pipes???

David

I don't have any pictures but I can take some. As soon as I get it over to my friends house we will pull a side pipe and take measurements just to know 100% what we are dealing with. At this point all I know is that the side pipes are suppose to be 2.5" and they don't use packing but instead a internal louver or baffle. The brand is Firefly....they sound pretty good but not too loud and they arent's as deep as normal SPF pipes. Will follow up with results.....work has been insane so it may be a week or so on this item.

[blykins]

A hydraulic roller cam that big in a 427 would float the valves before it made any power and would be a turd the rest of the time...

I don't use hydraulic rollers that big in my 480-490 inch FEs...

[Detroit Bill]

Originally Posted by DAVID GAGNARD

Unless you go with a "modern" type engine,you will not have a smooth idling,banshee off idle engine, push rod,carbed, stroker motors just don't do that and make 585hp....


david

I am not sure that is completely true. A stroked 427/482 FE may not idle well but it will pull hard off idle. In a Cobra the tires will be spinning in any event. The HP/TQ is not peaky it is linear. I realize the OP has a Windsor but since he is gathering information that should be pointed out. A 585 HP 427/482 is very different than a 585 hp 351/427.

Good luck!

[Dwight]

ACE
look at Classic Cobra Pack mufflers 3" with the louvers turned to the engine. Measure your old muffler and see if you can install longer Cobra Packs.
When you install longer mufflers, they are quieter but allow more exhaust out.

My 354 / 302 stroker put made over 400 rwh - tq and I think a lot of it was my exhaust system.

Classic Chambered Exhaust Inc. - Cobra

[DAVID GAGNARD]

Originally Posted by Detroit Bill

I am not sure that is completely true. A stroked 427/482 FE may not idle well but it will pull hard off idle. In a Cobra the tires will be spinning in any event. The HP/TQ is not peaky it is linear. I realize the OP has a Windsor but since he is gathering information that should be pointed out. A 585 HP 427/482 is very different than a 585 hp 351/427.

Good luck!

Bill:

I agree with you 100%,I was referring to a small block stroker making 585 hp.....A big block stroker making the same hp will be a lot "tamer" and streetable engine than the 427 small block stroker.......

David