B303 and other secret Coupe modifications

n20capri · Post by **n20capri** » Mon Apr 27, 2009 3:19 am

i posted pics of my cam years ago...but I can't find the pics...It didn't say B-303 on it and I'm fairly certain it didn't have a B-303

ricko302 · Post by **ricko302** » Mon Apr 27, 2009 10:55 am

Just measure the lobes on the camshaft. Height minus the width times 1.6 will equal the valve lift. LIFT = [ (H-W) X 1.6 ]

(Stock HO =0.444") (B-303=0.480")

Pretty easy if you have access to measuring tools.
Lets get to the bottom of this.

86capriasc · Post by **86capriasc** » Mon Apr 27, 2009 1:18 pm

If you read this thread, we have gone over this before. I still haven't taken it down to get it measured either.

http://www.ascmclaren.org/phpBB/viewtop ... t=b303+cam

I will try to get him up here with his tools and see if we can get the specs with the degree wheel using the original motor on the stand. He will know how to do it.

tfs2121 · Post by **tfs2121** » Mon Apr 27, 2009 11:27 pm

ok ok this wed or th i will pull the cam out of my original motor. then i will take it to work on fri and mic it out.

86capriasc · Post by **86capriasc** » Tue Apr 28, 2009 12:27 pm

I talked to my buddy last night and he is going to bring up degree wheel and other tools so we can get this cam thing figured out. I will keep everyone posted.

Tom S. · Post by **Tom S.** » Tue Apr 28, 2009 5:43 pm

86capriasc wrote:I talked to my buddy last night and he is going to bring up degree wheel and other tools so we can get this cam thing figured out. I will keep everyone posted.

Good cause I'd bet that it's no different than a regular 5.0 HO.

85McLaren · Post by **85McLaren** » Tue Apr 28, 2009 6:06 pm

I had pulled the cam from my 85 at one time to put a B-303 in it. I assumed the car was suppose to have one in it. Because I recognized my idle was from a factory 85 cam, I figured someone might have changed it depending on where they lived (not passing a smog test, etc.), but need to find it in my shed. It definitely did not say B-303 at the end of it.

I actually put a B-303 in it and it sounded WAY different when cold. When it warmed up, it was less noticable - but still noticable. I will see if I can find that same cam. I have about 4 or 5 cams, but I think I labeled the box on each of my cars that they came out of.

Of couse - my finding on my particular car doesn't prove some didn't come with the b-303, but from what I know - my car did not.

I still think the majority of these engines changes are taken out of context as to what the 85 5-speed motors had in them anyway (cam, lifters, headers, exhaust, etc.) was different than the 84 anyway. First year roller motor. I can also tell you that on my 85, the valve springs were no different than my regular other 5.0's are. Had a buddy years ago bring his spring tension checker tool to check the tension as I didn't know if the springs were able to take the little extra lift of the B-303. He said they fine and gave me no indication of them being some high tension performance aftermaket spring. I have my 86 intake and valve covers off and the springs are no different either. The headers are factory 86 headers. The is not any room (thickness) to port inside of these factory headers.

Believe me - I would LOVE to think we have a little higher performance parts, but I can prove that my coupes do not have any that I have seen yet ....

I am not trying to dissapoint anyone. Just telling the story for my coupe cars as I see it. I hope I can prove myself wrong or someone here can come up with hard evidence that disproves any of this comment.

Jason

Indiana,Dave · Post by **Indiana,Dave** » Fri May 01, 2009 12:34 pm

Well, I agree with part of that statement. My car really rumbles when the motor is cold. It calms down some when at operating temperture.

I have to disagree with it being same as 85 GT motor. my car doesn't
sound like a GT. I don't believe the 86 and up cars got the b 303 cam.
the fuel injection system wouldn't tolerate it very well. I am no expert
just a another car nut. I will watch this topic with great interest.

I still like the idea of a get together in NJ. We could autopsy a nice low mile 86 coupe and answer this question.

ChuckG · Post by **ChuckG** » Fri May 01, 2009 5:58 pm

I do recall my '85 feeling strong than the '86, despite the advertised HP increase. Could just be psychological, but I swear I noticed.

Wonder if anyone has data on the two, bone stock? Anyone do any dyno tests?

Indiana,Dave · Post by **Indiana,Dave** » Fri May 01, 2009 9:42 pm

My car has been on a chassis dyno. Unfortunatley, the man I bought the car from has had some memory issues after surgery. He couldn't remember the numbers..he has worked @ Roush, Saleen, Cosworth in the last 30 years.. I guess if you are going to buy

a low production
number car he is the kind of guy you want to buy it from.

85McLaren · Post by **85McLaren** » Sat May 02, 2009 9:49 pm

I will try to post some pics once I find my cable

But anyway if anyone has any time on their hands to trace the number on the cam - it says - K26.... I have about 3 or 4 different cams in my shed, but I believe this is the one that came out of my 85 mclaren. I strongly believe this is a regular 85 or 86 cam.....

Jason

jeffmclaren · Post by **jeffmclaren** » Sun May 03, 2009 5:15 am

I was also one to believe these cars had B303's but...

I just checked the lobe lift on the cam in my '85 coupe, and it is a stock 5.0 HO cam, not the B303.

Oh well.

85McLaren · Post by **85McLaren** » Sun May 03, 2009 1:47 pm

Well - maybe some got it, but I know mine seemed normal. It may have been a 'hit' or 'miss' thing, but I have #002 86 coupe and I know by the sound that she doesn't have one.

I will go back to the original statement and state that the changes made to ALL 85 5.0 5-speeds were probably what some of these rumors were....

(However - maybe some got lucky - or in my opinion - unlucky. The factory 85/86 cam will outperform the B-303 in an 86 car where the heads were 'crap'.)

Jason

BRYAN ROGERS · Post by **BRYAN ROGERS** » Mon May 04, 2009 6:12 am

My 93 has a B cam in it. You can hear it idle briefly in this video-

http://www.youtube.com/watch?v=Cl9y3Dc7UA4

Sandy · Post by **Sandy** » Mon May 04, 2009 5:15 pm

COUPE SPEAK:--

1984 & 1985 did NOT have a B-303 Cam

1986 Coupes DID have a b-303 cam.

That is what was verbally told to me by one of the
floor managers....at the time (1986)