Ultimate stockish 928 engine combo?
12-02-2005, 12:10 PM
#1
Rennlist Member
Thread Starter
Ultimate stockish 928 engine combo?
All this talk over the years about mixing and matching stock components, got me thinking that the best combo , non GTS engine, could be the 85-86 US set up with S4 heads.
We always are talking about putting the 85-86 cams on the S4, or using the 85 block for the 4.7-5 liter conversion, and then use the two valve heads. But, what about if an 85 owner wanted to really hop up his engine, wouldnt the trick set up be to just add some US S4 928 heads to it, and then convert the cams to S4 style as i have done with the driver side exhaust. (ie $400)
Then, you would have a higher compression, in the 11:1+ range, the bigger valve heads, and the 85-86 intake, which some say flows better than the US S4 flappy stuff. Ive got my flappy pegged anyway, and notice, in spirited driving , i never run below 3500rpm anyway, so the flappy really isnt needed. Also, there has been thought that the 85 intake may be pretty darn good.
I think that is the last combination we have to see yet in the mixing and matching of engine parts!
Mk
We always are talking about putting the 85-86 cams on the S4, or using the 85 block for the 4.7-5 liter conversion, and then use the two valve heads. But, what about if an 85 owner wanted to really hop up his engine, wouldnt the trick set up be to just add some US S4 928 heads to it, and then convert the cams to S4 style as i have done with the driver side exhaust. (ie $400)
Then, you would have a higher compression, in the 11:1+ range, the bigger valve heads, and the 85-86 intake, which some say flows better than the US S4 flappy stuff. Ive got my flappy pegged anyway, and notice, in spirited driving , i never run below 3500rpm anyway, so the flappy really isnt needed. Also, there has been thought that the 85 intake may be pretty darn good.
I think that is the last combination we have to see yet in the mixing and matching of engine parts!
Mk
12-02-2005, 01:13 PM
#3
Drifting
i thought some guy in australia did this allready and the compression ratio was much to high for pump gas. i think 928 intl supplied the short block.
what gains will the spacers on the S4 intake give? what about the over bored throttle body?
what gains will the spacers on the S4 intake give? what about the over bored throttle body?
12-02-2005, 01:24 PM
#4
Race Director
The stock S4-GT-GTS manifolds seem very good with stock 5.0L engines...and with spacers do good enough to support 500rwhp or more on boosted cars? For the ultimate setup....its gotta be the individual intakes like Don Hanson or Louie Ott sun...they were 50whp better than the stock intake!
I think the right setup 5.0L NA engine probably could push better than 350rwhp! Steve Pappin got 349whp without headers + smog legal (also an automatic!)
I think the right setup 5.0L NA engine probably could push better than 350rwhp! Steve Pappin got 349whp without headers + smog legal (also an automatic!)
12-02-2005, 01:55 PM
#5
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Brian;
Not to dis anyone, but Pappin didn't get 349 rwhp. That number was a guesstimate of an extrapolation from two different dyno runs, one being dynojet, one Mustang IIRC. Though, he did do some nice things to that car.
Not to dis anyone, but Pappin didn't get 349 rwhp. That number was a guesstimate of an extrapolation from two different dyno runs, one being dynojet, one Mustang IIRC. Though, he did do some nice things to that car.
12-02-2005, 02:20 PM
#6
Well for anybody wanting to try this I have a set of GT heads with the GTS water jacket mod, modified 85-86.5 cams and a fully ported GT manifold for sale. Depending on what you want extra, $2750
12-02-2005, 02:42 PM
#7
Rennlist Member
No Jim, the spacers were not developed by Louis, I did tthem. And you know this for a fact, as you do many other facts that you choose to distort to either cut us down, or make yourself look, ahh, bigger/better, whatever. You do this to intentionally provoke us/me and, as everyone knows, you help turn a spark into a fire.
Grow up.
Grow up.
Last edited by Fastest928; 12-02-2005 at 03:32 PM.
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12-02-2005, 02:56 PM
#8
Rennlist Member
Mark,
That engine has been built, runs close to 12 to one, and requires 100+ octane! One customer that I know who did it used the S4 manifold with stock injection and ign system from the 85 with no flappy .. it is actually removed. It ran for a short period of time and threw a belt ... I still have the pistons here. Hey, now there is a way to notch the pistons !
The ign timing is a function of cams more than anything else as they have the largest effect on where the peak hp/tq will fall. The stock ign/fueling system is 90% good for just about anything built to date. Even Sterling could use it on his engine and probably make more power. Tunign aftermarket efi is difficult for street, but easy for race
My ideal 5.0 engine - stock crank, GTS pistons slightly modified, long rods, big valves, DEVEK B1 cams, stock intake modified, stock fuel/ign system with SMT6, 1 3/4 headers, 3.5 exhaust.
I have tested spacers on three engines, so far, only seems to work with B1 cams.
Mark, want a cheap race engine ... build it like scots ... just kidding! Get a set of JE pistons for 103ish mm, bore the block and have it coated, do the heads with big valves and use B1 Cams. use stock crank and rods ... have fun...
That engine has been built, runs close to 12 to one, and requires 100+ octane! One customer that I know who did it used the S4 manifold with stock injection and ign system from the 85 with no flappy .. it is actually removed. It ran for a short period of time and threw a belt ... I still have the pistons here. Hey, now there is a way to notch the pistons !
The ign timing is a function of cams more than anything else as they have the largest effect on where the peak hp/tq will fall. The stock ign/fueling system is 90% good for just about anything built to date. Even Sterling could use it on his engine and probably make more power. Tunign aftermarket efi is difficult for street, but easy for race
My ideal 5.0 engine - stock crank, GTS pistons slightly modified, long rods, big valves, DEVEK B1 cams, stock intake modified, stock fuel/ign system with SMT6, 1 3/4 headers, 3.5 exhaust.
I have tested spacers on three engines, so far, only seems to work with B1 cams.
Mark, want a cheap race engine ... build it like scots ... just kidding! Get a set of JE pistons for 103ish mm, bore the block and have it coated, do the heads with big valves and use B1 Cams. use stock crank and rods ... have fun...
12-02-2005, 03:41 PM
#9
Rennlist Member
Jim,
Again, you know nothing about what Louis and I do or discuss, or do you? First and foremost, IT IS NONE OF YOUR BUSINESS. You seem to misunderstand quite a bit ... CEASE AND DESIST IMMEDIATELY.
Again, you know nothing about what Louis and I do or discuss, or do you? First and foremost, IT IS NONE OF YOUR BUSINESS. You seem to misunderstand quite a bit ... CEASE AND DESIST IMMEDIATELY.
12-02-2005, 08:56 PM
#10
Race Director
Originally Posted by Scott M.
Brian;
Not to dis anyone, but Pappin didn't get 349 rwhp. That number was a guesstimate of an extrapolation from two different dyno runs, one being dynojet, one Mustang IIRC. Though, he did do some nice things to that car.
Not to dis anyone, but Pappin didn't get 349 rwhp. That number was a guesstimate of an extrapolation from two different dyno runs, one being dynojet, one Mustang IIRC. Though, he did do some nice things to that car.
I thought Pappy had a dyno run of 349rhwp? What was his actual runs? Probaly closer to Kiborts 33?whp?
12-03-2005, 01:31 AM
#11
Rennlist Member
Thread Starter
thats what i was thinking about the 85 block with S4 heads. wonder how much 2points of compression would work out to help. sounds like it would be a great race engine, especially since the fuel and spark would be fine with the stock stuff. Ive heard, 3% for each point of compression. 6% for the 2 points, for about 25hp or so?
anyway, hey, cut out the scot cracks!!! (*too painful!!) i think we made only one mistake, and one BIG mistake. i think it was those darn used rings, but who knows!!
scots car has about 20min on the motor, only a few more hours and we will know!
its too bad that 12:1 engine only ran a short while. would have been an interesting data point for compression and the 85 intake .
I remember hearing of your dyno tests of the spacers. sounds like they dont do much for our 5 liter engines, but can help the larger engines. I wonder if there are good porting jobs on the intake and a larger throttle body that can help a 5 liter stock set up. As you know, we did test the Tom C. intake mods with the dual inlets to the plennum, and we maybe gained 3-4hp. so maybe the stock stuff is as good as you say.
I think your right about the race engine! you could still keep the stock 928 displacement max of 5.4 liter, and do it with bore and make it a high reving wanna be race engine. ....... someday, hopefully a while away!! (knock knock !)
MK
anyway, hey, cut out the scot cracks!!! (*too painful!!) i think we made only one mistake, and one BIG mistake. i think it was those darn used rings, but who knows!!
scots car has about 20min on the motor, only a few more hours and we will know!
its too bad that 12:1 engine only ran a short while. would have been an interesting data point for compression and the 85 intake .
I remember hearing of your dyno tests of the spacers. sounds like they dont do much for our 5 liter engines, but can help the larger engines. I wonder if there are good porting jobs on the intake and a larger throttle body that can help a 5 liter stock set up. As you know, we did test the Tom C. intake mods with the dual inlets to the plennum, and we maybe gained 3-4hp. so maybe the stock stuff is as good as you say.
I think your right about the race engine! you could still keep the stock 928 displacement max of 5.4 liter, and do it with bore and make it a high reving wanna be race engine. ....... someday, hopefully a while away!! (knock knock !)
MK
Originally Posted by marc@DEVEK
Mark,
That engine has been built, runs close to 12 to one, and requires 100+ octane! One customer that I know who did it used the S4 manifold with stock injection and ign system from the 85 with no flappy .. it is actually removed. It ran for a short period of time and threw a belt ... I still have the pistons here. Hey, now there is a way to notch the pistons !
The ign timing is a function of cams more than anything else as they have the largest effect on where the peak hp/tq will fall. The stock ign/fueling system is 90% good for just about anything built to date. Even Sterling could use it on his engine and probably make more power. Tunign aftermarket efi is difficult for street, but easy for race
My ideal 5.0 engine - stock crank, GTS pistons slightly modified, long rods, big valves, DEVEK B1 cams, stock intake modified, stock fuel/ign system with SMT6, 1 3/4 headers, 3.5 exhaust.
I have tested spacers on three engines, so far, only seems to work with B1 cams.
Mark, want a cheap race engine ... build it like scots ... just kidding! Get a set of JE pistons for 103ish mm, bore the block and have it coated, do the heads with big valves and use B1 Cams. use stock crank and rods ... have fun...
That engine has been built, runs close to 12 to one, and requires 100+ octane! One customer that I know who did it used the S4 manifold with stock injection and ign system from the 85 with no flappy .. it is actually removed. It ran for a short period of time and threw a belt ... I still have the pistons here. Hey, now there is a way to notch the pistons !
The ign timing is a function of cams more than anything else as they have the largest effect on where the peak hp/tq will fall. The stock ign/fueling system is 90% good for just about anything built to date. Even Sterling could use it on his engine and probably make more power. Tunign aftermarket efi is difficult for street, but easy for race
My ideal 5.0 engine - stock crank, GTS pistons slightly modified, long rods, big valves, DEVEK B1 cams, stock intake modified, stock fuel/ign system with SMT6, 1 3/4 headers, 3.5 exhaust.
I have tested spacers on three engines, so far, only seems to work with B1 cams.
Mark, want a cheap race engine ... build it like scots ... just kidding! Get a set of JE pistons for 103ish mm, bore the block and have it coated, do the heads with big valves and use B1 Cams. use stock crank and rods ... have fun...
12-03-2005, 10:12 PM
#12
Rennlist Member
If the heads were done right, I bet we could get to the 550-600 rwhp at 8000 rpm and make one hell of a lot of noise
And that would be fun.
My next engine will be very similar and should make over 600 rwhp at 7200 and rev to 8k.
Waiting for rods.
And that would be fun.
My next engine will be very similar and should make over 600 rwhp at 7200 and rev to 8k.
Waiting for rods.
12-04-2005, 09:26 PM
#15
Race Director
Originally Posted by marc@DEVEK
If the heads were done right, I bet we could get to the 550-600 rwhp at 8000 rpm and make one hell of a lot of noise
And that would be fun.
My next engine will be very similar and should make over 600 rwhp at 7200 and rev to 8k.
Waiting for rods.
And that would be fun.
My next engine will be very similar and should make over 600 rwhp at 7200 and rev to 8k.
Waiting for rods.
8K 928 V8.....can't be a stroker? Hot cams/heads on a serious overbore stock stroke engine...kinda like the 5.4 low compression? That would be something!