Engine blocks and strokers
10-07-2005, 07:51 PM
#46
Nordschleife Master
Join Date: Sep 2004
Location: Not close enough to VIR.
Posts: 9,429
Likes: 0
Received 2 Likes
on
2 Posts
Originally Posted by EB338
So what all am I missing not being a "member" now???
10-07-2005, 09:06 PM
#48
That crossover - would you sell that too Sterling? I need an exhaust for the 78 probably.
10-08-2005, 01:50 AM
#49
Road Warrior
Rennlist Member
Rennlist Member
arrrrggghhh... I waited as long as I could for a shot at your system sterling... finally just did mine w/devek L2 1 7/8" headers. devek xpipe w/random cats, hollow reasonators w/mandral 3" dual stainless to the rear w/a final hollow 2in 2out reasonator (flowmaster), forgot what was used up front, but it sounds quieter than my old 2:1 928SP race pipe and RMB w/stock cats.... gotta take a pic someday...
but I"m frankly not so sure 2.5" is so bad for just a 6.4L NA car, based on what I've been reading/hearing... lots of cheby/ferd boys use free flow 2.5" stuff on HP street rods w/no problem, according to a bunch of muffler pros... last time I ran 3" was on a 440cu HP RV motor, with 36 glass packs - rarely needed to use the air horns/motor might have been louder anyway.... on the shark, I was too cheap to do both and compare, so I decided to err on the big side where it would fit (up to the rear reasonator).... stuff like that drove me nuts, as there seemed to be lots of different opinons, but little hard dyno stuff to review w/similar conifgs (cams, ports, header sizes, etc), and dyno time/fabrication/tuning time adds up fast....
I was pleasantly amazed to see the OEM ECU's tune so easily and still able to deliver decent performance and AF ratios all the way up from a smooth clean idle w/nothing more than an ARRFPR, and messing w/the chips and fuel pressure a bit.... guess that OEM stuff isn't too bad in the later iterations/versions, course having someone that knows what screw to turn helps a lot/makes it look easy... course, when I look at sterlngs motec, I just can't stop drooling over all the cool stuff it can adjust/do....
always seems the last 5-10% takes 90% of the effort/time... thank god for duct tape
but I"m frankly not so sure 2.5" is so bad for just a 6.4L NA car, based on what I've been reading/hearing... lots of cheby/ferd boys use free flow 2.5" stuff on HP street rods w/no problem, according to a bunch of muffler pros... last time I ran 3" was on a 440cu HP RV motor, with 36 glass packs - rarely needed to use the air horns/motor might have been louder anyway.... on the shark, I was too cheap to do both and compare, so I decided to err on the big side where it would fit (up to the rear reasonator).... stuff like that drove me nuts, as there seemed to be lots of different opinons, but little hard dyno stuff to review w/similar conifgs (cams, ports, header sizes, etc), and dyno time/fabrication/tuning time adds up fast....
I was pleasantly amazed to see the OEM ECU's tune so easily and still able to deliver decent performance and AF ratios all the way up from a smooth clean idle w/nothing more than an ARRFPR, and messing w/the chips and fuel pressure a bit.... guess that OEM stuff isn't too bad in the later iterations/versions, course having someone that knows what screw to turn helps a lot/makes it look easy... course, when I look at sterlngs motec, I just can't stop drooling over all the cool stuff it can adjust/do....
always seems the last 5-10% takes 90% of the effort/time... thank god for duct tape
10-08-2005, 04:45 AM
#51
Rennlist Member
We have been selling dual for big engine for quite some time, and selling 3.5 for both early and late 928 for over 10 years!
Bottom line is this:
under 380 - 400 rwhp - 3.5 single
over 380 - 400rwhp - 3" dual
We have also built a 440 rwhp street stroker with a 4" single, dual 3" cats ... worked very well.
We have built many stroker at 400 rwhp+ with both 3.5 9usually with stock S4 cams, or duals 3", and
We use dual 3" cats for both systems ... works great.
Have fun
Marc
Bottom line is this:
under 380 - 400 rwhp - 3.5 single
over 380 - 400rwhp - 3" dual
We have also built a 440 rwhp street stroker with a 4" single, dual 3" cats ... worked very well.
We have built many stroker at 400 rwhp+ with both 3.5 9usually with stock S4 cams, or duals 3", and
We use dual 3" cats for both systems ... works great.
Have fun
Marc
10-08-2005, 12:06 PM
#52
Racer
Thread Starter
Join Date: Oct 2005
Location: middle of nowhere, USA
Posts: 309
Likes: 0
Received 0 Likes
on
0 Posts
Sterling:
How thick are your sleeves? I assume you bored beyond 104 to make room for the sleeve? What oiling modifications if any did you make when building this engine?
How thick are your sleeves? I assume you bored beyond 104 to make room for the sleeve? What oiling modifications if any did you make when building this engine?
10-08-2005, 02:59 PM
#54
Racer
Thread Starter
Join Date: Oct 2005
Location: middle of nowhere, USA
Posts: 309
Likes: 0
Received 0 Likes
on
0 Posts
Vilhuer/Erkka:
Any idea where I could find more information on these "support rings" you mentioned earlier? I finally got my head out of my rear and read through the link to your perfect block for a stroker thread. Are the support rings you mentioned the same thing as "fire ringing" that Greg Gray was talking about in that thread? (Greg, are you watching this thread?) Any more data or conclusions since that thread? How does the use of sleeves factor into your wall thickness calculations? Were you already planning on the use of sleeves or was the concern and measurement in that thread based on trying not to use them? How thick are the sleeves we typically end up using and can we count on them for any kind of structural assistance or are they pretty much there for a surface only?
Based on very rough assumptions here if we were to use the block filler and deck plates like Sterling, we are only trying to reinforce roughly 4.5" of the outsides of the bores between the deck plate and the filler. I still am not sure where to come up with any information about the impact of wrapping the outside of the bore for support. I think my biggest concern in that area still becomes the ability of the material to transfer heat. Aluminum soaks up and passes heat at a very different rate than steel so I am concerned an outer steel sleeve would trap heat in the original bore material and ultimately further weaken it. Not to mention the different rates of expansion and contraction. But as I said before that must be manageable since the inner sleeves would be in the same situation. I am similarly concerned about the application of block filler around the full height of the bores. I know there is an epoxy type material out there being used to rebuild heavy equipment parts like dozer sprockets and big truck spindles that bonds to the original material well enough to then be machined down, perhaps it would work or there is something similar for aluminum we could coat the bores in other than the block filler. I don't know if we could use a perforated steel sleeve around the outside? Could we come up with an aluminum sleeve possibly welded in place like the deck plate? Perhaps even a complete insert that would have webbing between these outer sleeves to brace the outside of the bores to the neighboring bore and the block? Im again just thinking out loud here.
Any idea where I could find more information on these "support rings" you mentioned earlier? I finally got my head out of my rear and read through the link to your perfect block for a stroker thread. Are the support rings you mentioned the same thing as "fire ringing" that Greg Gray was talking about in that thread? (Greg, are you watching this thread?) Any more data or conclusions since that thread? How does the use of sleeves factor into your wall thickness calculations? Were you already planning on the use of sleeves or was the concern and measurement in that thread based on trying not to use them? How thick are the sleeves we typically end up using and can we count on them for any kind of structural assistance or are they pretty much there for a surface only?
Based on very rough assumptions here if we were to use the block filler and deck plates like Sterling, we are only trying to reinforce roughly 4.5" of the outsides of the bores between the deck plate and the filler. I still am not sure where to come up with any information about the impact of wrapping the outside of the bore for support. I think my biggest concern in that area still becomes the ability of the material to transfer heat. Aluminum soaks up and passes heat at a very different rate than steel so I am concerned an outer steel sleeve would trap heat in the original bore material and ultimately further weaken it. Not to mention the different rates of expansion and contraction. But as I said before that must be manageable since the inner sleeves would be in the same situation. I am similarly concerned about the application of block filler around the full height of the bores. I know there is an epoxy type material out there being used to rebuild heavy equipment parts like dozer sprockets and big truck spindles that bonds to the original material well enough to then be machined down, perhaps it would work or there is something similar for aluminum we could coat the bores in other than the block filler. I don't know if we could use a perforated steel sleeve around the outside? Could we come up with an aluminum sleeve possibly welded in place like the deck plate? Perhaps even a complete insert that would have webbing between these outer sleeves to brace the outside of the bores to the neighboring bore and the block? Im again just thinking out loud here.
10-08-2005, 03:05 PM
#55
Racer
Thread Starter
Join Date: Oct 2005
Location: middle of nowhere, USA
Posts: 309
Likes: 0
Received 0 Likes
on
0 Posts
I guess if we really wanted to we could cut the bores out completely and weld in thicker ones, welded low enough to then apply the block filler to cover the weld area for further support...........If we could get in there with the wleder.......
10-08-2005, 11:56 PM
#56
Originally Posted by EB338
Vilhuer/Erkka:
Perhaps even a complete insert that would have webbing between these outer sleeves to brace the outside of the bores to the neighboring bore and the block? Im again just thinking out loud here.
Perhaps even a complete insert that would have webbing between these outer sleeves to brace the outside of the bores to the neighboring bore and the block? Im again just thinking out loud here.
This exists on 944s already. Darton makes the sleeves. Quite Pricey, but very nice looking. 928 is 944 x2.
10-09-2005, 12:06 AM
#58
I honestly think Darton may have made the sleeves in Carl's New Racer motor. But he doesn't have any info on them.
No idea on website at this moment.
No idea on website at this moment.
10-09-2005, 12:18 AM
#59
Racer
Thread Starter
Join Date: Oct 2005
Location: middle of nowhere, USA
Posts: 309
Likes: 0
Received 0 Likes
on
0 Posts
Brendan:
You are referring to a sleeve for the outside of the bore correct? Are they used for the same reason I am looking (to reinforce a large overbore) or for some other purpose?
Are deck plates like Sterling installed a fairly common practice? I recall reading in another thread about someone getting deck plates from someplace called UTAH motorsports. Anyone heard of them?
You are referring to a sleeve for the outside of the bore correct? Are they used for the same reason I am looking (to reinforce a large overbore) or for some other purpose?
Are deck plates like Sterling installed a fairly common practice? I recall reading in another thread about someone getting deck plates from someplace called UTAH motorsports. Anyone heard of them?
10-09-2005, 12:23 AM
#60
I'm talking about a wet sleeve - remove the bore towers all together and replace it with ductile iron sleeves. Interlocked and machined to just fit the inner walls of the block area.
The plates are not common practice.
Garrity and Dave at motorsport in Utah are available to do deck plates without touching the original bores other then to prepare them for the plate welding. They can chime in here if listening. At that point the block would be rebored and honed or nikasiled.
The plates are not common practice.
Garrity and Dave at motorsport in Utah are available to do deck plates without touching the original bores other then to prepare them for the plate welding. They can chime in here if listening. At that point the block would be rebored and honed or nikasiled.