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ascMcLaren Enthusiasts
An asc McLaren forum for ALL Mustang and Capri based cars modified by Automotive Speciality Corporation, a Division of American Sunroof Corporation.
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85McLaren
Joined: 27 Sep 2004
Posts: 178
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 Posted: Sat Oct 02, 2004 1:29 am Post subject: camshaft |
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Just curious, I have an 85 and an 88 mclaren. I know the 85 has the b303 cam, but am curious if the 86s had the b-303. I know the B-303 cam does not play well at all with EFI cars. Since 86s were first year EFI with REALLY bad heads, just curious if the B-303 carried into the 86 year....
Jason |
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negusm
Site Admin
Joined: 25 Aug 2004
Posts: 5183
Location: Charlotte, NC
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| Posted: Sat Oct 02, 2004 2:24 am Post subject: |
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Vert or coupe?
I believe the B303 was ONLY in the coupe. Sandy can verify.
I beleive it was for both years.
Not sure why you think it didn't work well with EFI. I have never heard that. I have heard that it could be better with better heads and exhaust...but never that it was bad with EFI...
-Mike
_________________
1985 ascMcLaren Coupe - Midnight Blue
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Sandy
Joined: 26 Aug 2004
Posts: 6205
Location: Northern New Jersey GSP Exit 148
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| Posted: Sat Oct 02, 2004 2:57 am Post subject: |
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The story behind the B-303 Cam is a little known one. I don't like to tell it in print, for legal reasons. What I do know is heresay from 2 men who do not know one & other. One was from New Hampshire, the other from Michigan. Their stories mesh like 85-90%. It involves ONLY the 1985 & 1986 COUPES. Possibly the 25 1984s as well ~ but I only ever heard the "85 & 86" bantered about.
ASC wanted McLaren Engineering to "message" the engine. McLaren would not, due to legalities and responsibilties. So, asc went to Ford. You might refer to or think of Corvette's "Skunkworks" here. Things were changed en masse under the hoods, as a bunch of engines were "messaged" "late at night" Understand?????? Oh, like perhaps 300 or so engines. AFTER this was done, some of the wrong people got wind of it. Threats were made, etc, etc. asc wanted to be able to ADVERTISE the new goodies, but Ford threatened lawsuits, and even worse.
So, asc got the engines, but could never hype them. They were trying to accomplish a few things. ONE, and most important, a lumpy, rough idle and a rump rump rump exhaust note, and TWO more or less a start-up blueprint for the expected buyer to be off & running to a modified car blueprint from which to "carry-on" ~ much like many of you guys are doing.
To THAT end, and AGAIN, according to what Sandy was told by two very special people, whom I had no reason to doubt, the cars received the B-303 Cam, prototype valve springs, larger valves & valve guides, and SOME cars got the 3.73:1 gearing, and they all got a unique exhaust that was tweaked.
Man in New Hampshire, retired from Ford, was a racing director with Ford, and had input into the ascMcLaren project.
Man in Detroit, well - I'll stop there. Sorry.
The cars were also to get a modified braking system, which was to be 4-wheel disc brakes, and sintered metallic linings. Didn't happen simply because of the Feds requirement of add'l. crash testing, and nobody wanted to pay for the totalled cars. Other things as well were to be included. New Valve Covers (Cast Aluminum) Finned with ASC MC LAREN Logo cast into top surface, Engine Compartment Dress-Up Kit of chrome and other visually appealing items.
Back to the Engine. Another thing that was done to the engine was the replacing of valve springs & rocker ars to increase usable Rev. Limit to 7,000 RPM. The exhaust system:-
Upgraded exhaust header (Stainless Steel) internal mandrel bent - Exhaust Port Liners & Lower restriction exhaust with Tuned Muffler to reduce back pressure & enhance tone.
I was told the engine alterations were in fact..DONE, likewise the exhaust were done. The valve covers were applied to a handfull of car in 1985 (early) and the brakes were not touched. The chrome kit never happened.
IF your ascMcLaren COUPE idles lumpy, runs for like 2 minutes when cold & then stalls, but is strong on the immediate re-start, and at red lights that are loooong, the engine begines to surge UP and down, then yoiu hve the B-303 Cam.
Mine does all of those things.
There were other things that weree also done: Fr & Rr cambers were altered to max out performance of upgraded tire/wheel pkg. the suspension bushing durometer was increased and the power steering was re-calibrated. On 5-speed cars the shift linkage was shortened and given a tighter feel.
I'm going to bed, now.
_________________
Sandy passed away in 2012. He will be forever missed.
1990 Final Car prior to the 12 Silver Anny Editions
1990 Silver Pearl Anny Edition
1986 Coupe Full Pkg #109 of 114.
http://public.fotki.com/ascmclaren/ascmclaren_capris/sandys_mclarens/ |
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85McLaren
Joined: 27 Sep 2004
Posts: 178
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| Posted: Sat Oct 02, 2004 5:31 pm Post subject: |
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Thanks for the input Sandy. I think they had to keep their mouth shut about the B-303 because it is a non-emissions cam.
Mike - The reason I say it doesn't work as well in EFI cars (especially the 86-88s) is because they operate on a speed density system. In other words, they rely on manifold vacuum to regulate air/fuel ratio. The 85s were carbd as you know, so they would not be affected by the vacuum loss, except maybe for a softer brake pedal due to a lack of vacuum to the power brake booster. That is why Sandy is referring to surging. The 86-88 are VERY famous for this when you change the cam which changes vacuum. The computer doesn't know what to set the air/fuel ratio at. The car will run rich. The vacuum the B cam gives off at idle is close to what a stock cam gives off at part thottle (the further throttle goes open, the less vacuum you have in your manifold). The 86-88 EFI car's processor are pre-programmed to know at a certain vacuum (based on the stock cam) to give it a certain fuel ratio. With the B-cam, the computer is looking at the vacuum thinking the car is operating at part throttle and it dumping more fuel in the car.
The 89 and up (88 CA) cars were based on a "mass air" setup which doesn't rely on manifold vacuum as much to regulate air/fuel ratio.
Now that I have bored you to death - I'll stop.
(Great site - enjoy and will enjoy continuing to chat with everyone)
Jason |
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Sandy
Joined: 26 Aug 2004
Posts: 6205
Location: Northern New Jersey GSP Exit 148
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| Posted: Sat Oct 02, 2004 7:30 pm Post subject: |
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Jason, thank you for the informative explanation!  When I go weekly to start & run "Grey-Mac" I notice that during the first 90 seconds, she runs with a higher idle, and runs nicely. However, after 90 seconds, she begins to surge up and down, between 300 RPM and 800 RPM. If I leave it alone, she'll putter out & die. On the re-start, she is perfect & can & will idle endlessly without noticable surging. However, if I keep my foot on the gas pedal and keep the RPMs at 1,300 or thereabouts, she will not stall out, allthough at times I have to "juice it" a bit to even it out. When the TEMP gauge reaches the normal zone, she's fine!! In addition, should I "Start & Go" without any "warm-up period" she will *NOT* stall or surge, even at the first STOP sign! She will not act this way again that day. I can drive it 3 miles, park it for 6 hours, and she will not repeat this. It's only after sitting for 20+ hours. Is that due to the Cam ? I will tell you that I have driven another low mileage regular 1986 Capri RS 302 V-8 and my car feels like it has at least 100 H.P. more. My car can actually chirp its tires IN THE DRIVEWAY, at like under 5MPH. On the road, the power feels endless. I drove it that way only once. Crusing at 58 MPH, (Automatic, remember) I "punched" it, and let me tell you, it leaped forward like a tiger and downshifted hard and in the space of like 3 seconds was doing 84 MPH. It had loads more where that came from.
My friend's '86 RS is fast, but does not have the "feel" of power that my Mac has. His car is also an automatic, low mileage & babied. He has 31,000 on it at present, in 18 years. His is bone stock, except he revovered the seats in leather (grey).
_________________
Sandy passed away in 2012. He will be forever missed.
1990 Final Car prior to the 12 Silver Anny Editions
1990 Silver Pearl Anny Edition
1986 Coupe Full Pkg #109 of 114.
http://public.fotki.com/ascmclaren/ascmclaren_capris/sandys_mclarens/ |
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n20capri
Joined: 30 Aug 2004
Posts: 715
Location: Bensalem PA
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| Posted: Sat Oct 02, 2004 9:53 pm Post subject: |
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I don't think my car got the B cam...
Not that it matters...that cam is loooong gone... actually it's tucked away in the shed...
_________________
Mike
86 AscMcLaren Capri Coupe - #026 | 11.4@118 | 290/322
86 9L SVO
www.mikemartinelli.com
www.baldguydesigns.net
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n20capri
Joined: 30 Aug 2004
Posts: 715
Location: Bensalem PA
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| Posted: Sat Oct 02, 2004 9:55 pm Post subject: |
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| 85McLaren wrote: | Thanks for the input Sandy. I think they had to keep their mouth shut about the B-303 because it is a non-emissions cam.
Mike - The reason I say it doesn't work as well in EFI cars (especially the 86-88s) is because they operate on a speed density system. In other words, they rely on manifold vacuum to regulate air/fuel ratio. The 85s were carbd as you know, so they would not be affected by the vacuum loss, except maybe for a softer brake pedal due to a lack of vacuum to the power brake booster. That is why Sandy is referring to surging. The 86-88 are VERY famous for this when you change the cam which changes vacuum. The computer doesn't know what to set the air/fuel ratio at. The car will run rich. The vacuum the B cam gives off at idle is close to what a stock cam gives off at part thottle (the further throttle goes open, the less vacuum you have in your manifold). The 86-88 EFI car's processor are pre-programmed to know at a certain vacuum (based on the stock cam) to give it a certain fuel ratio. With the B-cam, the computer is looking at the vacuum thinking the car is operating at part throttle and it dumping more fuel in the car.
The 89 and up (88 CA) cars were based on a "mass air" setup which doesn't rely on manifold vacuum as much to regulate air/fuel ratio.
Now that I have bored you to death - I'll stop.
(Great site - enjoy and will enjoy continuing to chat with everyone)
Jason |
Couldn't have said it better myself...
_________________
Mike
86 AscMcLaren Capri Coupe - #026 | 11.4@118 | 290/322
86 9L SVO
www.mikemartinelli.com
www.baldguydesigns.net
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85McLaren
Joined: 27 Sep 2004
Posts: 178
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| Posted: Sun Oct 03, 2004 3:21 pm Post subject: |
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Now I will bore you guys with a little more info. The air/fuel ratio is determined by the MAP (Manifold Absolut Pressure) sensor. That is the little black box in middle of the rear of the firewall. That little black box stores what I will refer to as "look up tables" which have columns for vacuum and air/fuel ratio. Back in the late 80's, I knew a guy who made a replacement MAP sensor with different look-up tables to compensate for an aftermarket cam (like the B-303). And let me tell you - IT RAN GREAT (no surging, no running rich, etc). Therefore the air/fuel mixture was correct based on the different values in the MAP sensor. But guess what. From legal reasons, FORD made him stop producing and selling these MAP sensors. One reason is because FORD (motorsport) was creating a MASS-AIR kit conversion (which I have done on 2 88s and 3 86s). This conversion worked, but was also VERY expensive (back in the day). And guess what.... The MASS AIR cars were actually slower than the speed density system. The MASS-AIR system puts a 55mm MASS air meter in the intake hose track which limited airflow. This was done for emissions reasons (not for performance as many would think). It just worked out that the MASS AIR cars could "adapt" to changes as it no longer depended on manifold vacuum to regulate air/fuel ratio. Back in "the day," I did a lot of experimenting to help the 86-88 run better with different performance parts. Cheapest thing was to "mess" with the O2 sensors in the exhaust pipes. The computer also regulates air/fuel ratio by reading the exhaust gas from the O2 sensors. They are read in resistance (ohms). What I use to due was splice in different ohm resistors bought from radio shack until I could fool the computer into leaning it out more. For instance, if the computer reads a signal from the 02 sensor of "2 ohms," I would try different resistors to get it to 1.5 ohms. The computer would read the 1.5 ohms and give it the spark curve and air/fuel pressure based on the 1.5 ohm value.... They sell computer chips, etc. now that do this for $250 dollars. Damn, just think. I use to do some of this for $1 worth of parts from a local radio shack.... Times have sure changed....
Jason
(Just some more tech info to bore someone with) |
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Sandy
Joined: 26 Aug 2004
Posts: 6205
Location: Northern New Jersey GSP Exit 148
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n20capri
Joined: 30 Aug 2004
Posts: 715
Location: Bensalem PA
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| Posted: Sun Oct 03, 2004 11:06 pm Post subject: |
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| 85McLaren wrote: | Now I will bore you guys with a little more info. The air/fuel ratio is determined by the MAP (Manifold Absolut Pressure) sensor. That is the little black box in middle of the rear of the firewall. That little black box stores what I will refer to as "look up tables" which have columns for vacuum and air/fuel ratio. Back in the late 80's, I knew a guy who made a replacement MAP sensor with different look-up tables to compensate for an aftermarket cam (like the B-303). And let me tell you - IT RAN GREAT (no surging, no running rich, etc). Therefore the air/fuel mixture was correct based on the different values in the MAP sensor. But guess what. From legal reasons, FORD made him stop producing and selling these MAP sensors. One reason is because FORD (motorsport) was creating a MASS-AIR kit conversion (which I have done on 2 88s and 3 86s). This conversion worked, but was also VERY expensive (back in the day). And guess what.... The MASS AIR cars were actually slower than the speed density system. The MASS-AIR system puts a 55mm MASS air meter in the intake hose track which limited airflow. This was done for emissions reasons (not for performance as many would think). It just worked out that the MASS AIR cars could "adapt" to changes as it no longer depended on manifold vacuum to regulate air/fuel ratio. Back in "the day," I did a lot of experimenting to help the 86-88 run better with different performance parts. Cheapest thing was to "mess" with the O2 sensors in the exhaust pipes. The computer also regulates air/fuel ratio by reading the exhaust gas from the O2 sensors. They are read in resistance (ohms). What I use to due was splice in different ohm resistors bought from radio shack until I could fool the computer into leaning it out more. For instance, if the computer reads a signal from the 02 sensor of "2 ohms," I would try different resistors to get it to 1.5 ohms. The computer would read the 1.5 ohms and give it the spark curve and air/fuel pressure based on the 1.5 ohm value.... They sell computer chips, etc. now that do this for $250 dollars. Damn, just think. I use to do some of this for $1 worth of parts from a local radio shack.... Times have sure changed....
Jason
(Just some more tech info to bore someone with) |
lol definitely not boring...this is my type of stuff...
I have an EEC-Tuner in my car and I love to tweak the computer...I did the mass air conversion on my car 7+ years ago...fun stuff...
_________________
Mike
86 AscMcLaren Capri Coupe - #026 | 11.4@118 | 290/322
86 9L SVO
www.mikemartinelli.com
www.baldguydesigns.net
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5LiterMustang
Joined: 29 Aug 2004
Posts: 20
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| Posted: Mon Oct 04, 2004 4:33 pm Post subject: |
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luckily my 88 ASC/McLaren Mustang, as all California mustangs in 88, is mass air equipped from the factory. 
_________________
1991 LX 5.0 Notchback
1986 GT Convertible
1990 GT Hatchback
1988 ASC/McLaren Mustang |
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Sandy
Joined: 26 Aug 2004
Posts: 6205
Location: Northern New Jersey GSP Exit 148
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| Posted: Mon Oct 04, 2004 4:38 pm Post subject: |
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Why did you sell your 7-UP car ??
{My son & wife are both CRAZY for 7-UP. They buy a case of 30 every month! That's 30 cans a month, 15 apiece. Once in a while I swipe one, and they notice!!!} 
_________________
Sandy passed away in 2012. He will be forever missed.
1990 Final Car prior to the 12 Silver Anny Editions
1990 Silver Pearl Anny Edition
1986 Coupe Full Pkg #109 of 114.
http://public.fotki.com/ascmclaren/ascmclaren_capris/sandys_mclarens/ |
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tfs2121
Joined: 29 Aug 2004
Posts: 1823
Location: Commerce, MI
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| Posted: Tue Oct 05, 2004 3:53 pm Post subject: |
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| Sandy wrote: | The story behind the B-303 Cam is a little known one. I don't like to tell it in print, for legal reasons. What I do know is heresay from 2 men who do not know one & other. One was from New Hampshire, the other from Michigan. Their stories mesh like 85-90%. It involves ONLY the 1985 & 1986 COUPES. Possibly the 25 1984s as well ~ but I only ever heard the "85 & 86" bantered about.
ASC wanted McLaren Engineering to "message" the engine. McLaren would not, due to legalities and responsibilties. So, asc went to Ford. You might refer to or think of Corvette's "Skunkworks" here. Things were changed en masse under the hoods, as a bunch of engines were "messaged" "late at night" Understand?????? Oh, like perhaps 300 or so engines. AFTER this was done, some of the wrong people got wind of it. Threats were made, etc, etc. asc wanted to be able to ADVERTISE the new goodies, but Ford threatened lawsuits, and even worse.
So, asc got the engines, but could never hype them. They were trying to accomplish a few things. ONE, and most important, a lumpy, rough idle and a rump rump rump exhaust note, and TWO more or less a start-up blueprint for the expected buyer to be off & running to a modified car blueprint from which to "carry-on" ~ much like many of you guys are doing.
To THAT end, and AGAIN, according to what Sandy was told by two very special people, whom I had no reason to doubt, the cars received the B-303 Cam, prototype valve springs, larger valves & valve guides, and SOME cars got the 3.73:1 gearing, and they all got a unique exhaust that was tweaked.
Man in New Hampshire, retired from Ford, was a racing director with Ford, and had input into the ascMcLaren project.
Man in Detroit, well - I'll stop there. Sorry.
The cars were also to get a modified braking system, which was to be 4-wheel disc brakes, and sintered metallic linings. Didn't happen simply because of the Feds requirement of add'l. crash testing, and nobody wanted to pay for the totalled cars. Other things as well were to be included. New Valve Covers (Cast Aluminum) Finned with ASC MC LAREN Logo cast into top surface, Engine Compartment Dress-Up Kit of chrome and other visually appealing items.
Back to the Engine. Another thing that was done to the engine was the replacing of valve springs & rocker ars to increase usable Rev. Limit to 7,000 RPM. The exhaust system:-
Upgraded exhaust header (Stainless Steel) internal mandrel bent - Exhaust Port Liners & Lower restriction exhaust with Tuned Muffler to reduce back pressure & enhance tone.
I was told the engine alterations were in fact..DONE, likewise the exhaust were done. The valve covers were applied to a handfull of car in 1985 (early) and the brakes were not touched. The chrome kit never happened.
IF your ascMcLaren COUPE idles lumpy, runs for like 2 minutes when cold & then stalls, but is strong on the immediate re-start, and at red lights that are loooong, the engine begines to surge UP and down, then yoiu hve the B-303 Cam.
Mine does all of those things.
There were other things that weree also done: Fr & Rr cambers were altered to max out performance of upgraded tire/wheel pkg. the suspension bushing durometer was increased and the power steering was re-calibrated. On 5-speed cars the shift linkage was shortened and given a tighter feel.
I'm going to bed, now. |
sandy when i tore apart my motor i was looking for thoughs proto type valves and springs but i dont think i had them i know i have the B cam as my car sucks driving it cold im not to sure what the headders should have looked like but i thought mine were factory and my rocker arms seemd to have been factory. my car already had a new exhaust when i got it but thats gone now too
like you said you didnt want to type this out cuz some one was going to say its not true... well for my car it seems as thoug i only got the B cam
also what did they do to the shifter i always thought my car had a really short throw
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~Peter
1985 ASC McLaren Coupe |
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Sandy
Joined: 26 Aug 2004
Posts: 6205
Location: Northern New Jersey GSP Exit 148
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negusm
Site Admin
Joined: 25 Aug 2004
Posts: 5183
Location: Charlotte, NC
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| Posted: Tue Oct 05, 2004 5:40 pm Post subject: |
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Did they?
My shifter seems stock.
-Mike
_________________
1985 ascMcLaren Coupe - Midnight Blue
Under Restoration |
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