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tips, technology, tools and techniques related to vehicle driveline components

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turbodave
dave cox

(60 posts)

Registered:
04/30/2018 03:00PM

Main British Car:


Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: turbodave
Date: March 02, 2021 11:50AM

I was looking at more of a racey motor, but have now re-visited my expectations and would like to target a lower HP to keep the standard 3.9 pistons, and achieve a broader power band, making for an easier driving machine.

I've already pocketed the pistons, decked the block to raise the CR (should be around 10.5:1 plus/minus depending what I decide to do with the heads).

Engine will be used in an endurance race series.

Heads will be ported, have bullet guides, DW500 1.630" (41.4mm) and DW501 1.400" (35.6mm) 3-angle valves. I've already pocketed for whatever springs I could possibly need.

Running aftermarket injection through the 3,9 plenum with larger TB and shortened trumpets.

I have a set of SD1 Vitesse Volvo adjustable rockers I can use should I choose solid lifters.

Please share your recommendations for a camshaft - and if hydraulic or mechanical.
If Hydraulic, I'm assuming that I should look to the anti-pump up versions rather than the OE lifter?


turbodave
dave cox

(60 posts)

Registered:
04/30/2018 03:00PM

Main British Car:


Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: turbodave
Date: March 02, 2021 11:56AM

I should also add, I'm using the later serpentine front cover, so oil pressure/volume shouldn't be an issue.


mgb260
Jim Nichols
Sequim,WA
(2082 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: mgb260
Date: March 02, 2021 12:14PM

Crower 50232 with their Camsaver hydraulic lifters. Get an adjustable pushrod to figure proper pushrod length.


turbodave
dave cox

(60 posts)

Registered:
04/30/2018 03:00PM

Main British Car:


Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: turbodave
Date: March 02, 2021 06:56PM

Thanks Jim, This does seem to be a popular choice stateside.

These say "redline 5000 rpm" ? That seems a little low; maybe its assuming standard timing. I'd have thought an engine of that advertised duration would have revved harder than that?

Any chance you can run a desktop dyno sim to advise what looks like the best results?


mgb260
Jim Nichols
Sequim,WA
(2082 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: mgb260
Date: March 02, 2021 07:18PM

Dave, I think Crower's redline is really the powerband. Their cams have 4 degrees advance built in. With your higher compression I would retard it 4 degrees. I have a copy of a real dyno with the 50233 that has 247HP in a 3.9.
3.9 dyno.jpg



Edited 4 time(s). Last edit at 03/02/2021 07:33PM by mgb260.


MGBV8
Carl Floyd
Kingsport, TN
(4041 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB, Buick 215

authors avatar
Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: MGBV8
Date: March 03, 2021 09:25AM

That on an engine dyno, Jim? I would think it would take a fairly radical 3.9 with a bigger cam to get that at the wheels.


mgb260
Jim Nichols
Sequim,WA
(2082 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: mgb260
Date: March 03, 2021 10:27AM

Carl, yep. At the flywheel.



roverman
Art Gertz
Winchester, CA.
(3103 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: roverman
Date: March 03, 2021 02:52PM

"Endurance Racing", as-in 12-24 hours ? Best to read of trials and tribulations in this forum, with wet sump, racing RV8's.
Realistic rpm range ? Small mains/rods ? Cross bolted ? 240 hp. at rear wheels ? Flowed the heads ? Allowed a roller cam ?
Cool Case/ Tuftride the crank ? Good Luck, Art.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6008 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: BlownMGB-V8
Date: March 04, 2021 11:14AM

I got about that hp out of a 215 with a big carb and equal length headers, running the biggest hydraulic cam Comp ever made for the SBB (no longer available) and a 7K redline. After about 20K miles I cracked a piston and spun a bearing but it was great fun until then. OEM Hi-Po pistons, that 7 grand eventually did them in.

Jim


turbodave
dave cox

(60 posts)

Registered:
04/30/2018 03:00PM

Main British Car:


Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: turbodave
Date: March 05, 2021 11:48AM

Art,
240hp flywheel. Even 220hp flywheel would be competitive and still plenty of "fun"
I'm liking this cam; the more research I'm doing...
Will be small 3.9 small journal, the usual prep to the mains for improved oiling, serpentine front cover for plenty of oil, wet winged sump, heads as good as possible, mapped injection and ignition. Using the standard serp full height cap, but none Cross-bolted block. If cooling looks to be an issue, I'll immediately jump on a pierburg CWA200 pump and TinyCWA controller as Ive had good experiences with them.


MGBV8
Carl Floyd
Kingsport, TN
(4041 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB, Buick 215

authors avatar
Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: MGBV8
Date: March 06, 2021 09:43AM

Quote:
I have a copy of a real dyno with the 50233 that has 247HP in a 3.9.

You also mentioned the 50232 cam, Jim Just wanted to get clarification that this dyno sheet was with the bigger 50233 cam? I figure it, was looking at the top end.


mgb260
Jim Nichols
Sequim,WA
(2082 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: mgb260
Date: March 06, 2021 11:02AM

Carl, I meant the 50233. The 50232 is a little milder.


MGBV8
Carl Floyd
Kingsport, TN
(4041 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB, Buick 215

authors avatar
Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: MGBV8
Date: March 06, 2021 07:15PM

You did say 50233 on the dyno sheet post. Just wanted to be sure.

I have had a new 50232 to put in a 3.9 for years. Never did. My Buick 215 never quit screaming. I do like that dyno chart above. Shame it's not RWHP. :)


roverman
Art Gertz
Winchester, CA.
(3103 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: roverman
Date: March 09, 2021 05:11PM

"full height cap", bolt bosses above pan rail ? If so, I would drill and tap. Air flow is free hp. ! Allowed 300" or aftermarket heads ?


minorv8
Jukka Harkola

(216 posts)

Registered:
04/08/2009 06:50AM

Main British Car:
Morris Minor Rover V8

Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: minorv8
Date: March 22, 2021 01:52AM

Dave, I ran a Real Steel Tornado (?) hydraulic cam in my 4.6 litre engine. It was actually a Comp Cams grind. I have the Comp spec sheet somewhere, it has the Comp grind number. It might be another option since you are in the States.



roverman
Art Gertz
Winchester, CA.
(3103 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: roverman
Date: March 22, 2021 07:25PM

"Crower Cam Saver" Do they pray for the undersize base circles ?


mgb260
Jim Nichols
Sequim,WA
(2082 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: mgb260
Date: March 22, 2021 07:32PM

Art, They cut a little groove lengthwise on the lifter to put more oil on the lobe. Might lose 1-2 psi oil pressure. They also replace the wire clip with a C clip.
camsaver.jpg



Edited 1 time(s). Last edit at 03/22/2021 07:39PM by mgb260.


roverman
Art Gertz
Winchester, CA.
(3103 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: roverman
Date: March 23, 2021 07:49PM

I would like a small edm. hole in center of lifter , better.
Not to to derale your cam thoughts, Dave, have you considered a roller, solid or hydraulic ? Dan Jones,( this forum), has a cam core and I still have
some,( round lobe). Perhaps you and he could agree on a profile ? I have new gm. short-body lifters. Can be converted to mech., if need.
Art.


turbodave
dave cox

(60 posts)

Registered:
04/30/2018 03:00PM

Main British Car:


Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: turbodave
Date: March 24, 2021 02:26PM

Hey Art,
For me, just getting on the track is key. Heaven knows, a 50232 is about as easy to drive as anyone could want, so that's what Ill be running on the main and backup motor until I get the chassis dialed in. I can always change it later, but that's my plan for now.

Cheers,


MGBV8
Carl Floyd
Kingsport, TN
(4041 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB, Buick 215

authors avatar
Re: Changed my mind - now looking for a solid 240hp from 3.9. What cam?
Posted by: MGBV8
Date: March 26, 2021 09:14AM

Wonder what the fuel consumption difference would be between a 50232 vs a 50230?
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