[GMCnet] Caddy 500 camshaft recomendations
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Bill Dolinsky
Dec 18, 2014, 12:35:56 AM12/18/14
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Starting to think about my 1973 caddy 500. Stock soap bar Pistons, small chamber heads.
Trying to decide on camshaft. Want to run regular gas so not so sure I want a torque cam, don't want excessive cylinder pressure going up mountains
when things get hot. Wouldn't mind more lift and duration, don't think torque would drop significantly at cruise rpm with potential gains in second
gear.
Don't want so much lift or ramp rate that I would have to worry about wiping out a cam or stressing stock rockers.
How bad is a stock re grind, can't seem to find numbers for them? It seems like a safe bet with great torque at cruise with a slight decrease of
torque say in second gear, 3500-3800 rpm.
How many rpm would a gmc do at say 50 mph in second gear?
My fear of a torque cam comes from my neighbours GMC, I fear perhaps PO put in a torque cam and he has been running regular gas. He has additional
problems, it's equipped with a very early fuel injection system that he seems unable to get information for. He said he contacted the manufacture and
he said they do not provide any information for that system anymore. The module is mounted on a piece of plywood under the passenger seat and he has
nice headers on it but burns almost as much oil as gas (doesn't smoke) however going up steep hills he says say press on the gas at 2200 rpm the
engine detonates like crazy, puts the pedal to the floor and detonation stops even without dropping to passing gear.
I went and checked it out for him in the driveway last week and set his initial at about 10 degrees, didn't take note where it was set initially
however way advanced. Revved up the engine and while he has a fuel injection distributor that has no mechanical or vacuum advance his computer is not
giving any advance and will however drop advance with manifold vacuum drop so Map sensor is working at least so guessing he had his initial set at
somewhere around 25-35 degrees. Anyway he's looking for an engine to build, wants me to build and change but I don't se me having time in the near
future. Oil analysis doesn't look good and I suggested picking up a leak down tester and checking, mine is home made and one gauge is toast.
Anyway I want to replace the original 25 year old camshaft, wouldn't mind more power but not at the expense of Valvetrain reliability and detonation.
Also, Falcon engine parts on ebay, any good?
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Trying to decide on camshaft. Want to run regular gas so not so sure I want a torque cam, don't want excessive cylinder pressure going up mountains
when things get hot. Wouldn't mind more lift and duration, don't think torque would drop significantly at cruise rpm with potential gains in second
gear.
Don't want so much lift or ramp rate that I would have to worry about wiping out a cam or stressing stock rockers.
How bad is a stock re grind, can't seem to find numbers for them? It seems like a safe bet with great torque at cruise with a slight decrease of
torque say in second gear, 3500-3800 rpm.
How many rpm would a gmc do at say 50 mph in second gear?
My fear of a torque cam comes from my neighbours GMC, I fear perhaps PO put in a torque cam and he has been running regular gas. He has additional
problems, it's equipped with a very early fuel injection system that he seems unable to get information for. He said he contacted the manufacture and
he said they do not provide any information for that system anymore. The module is mounted on a piece of plywood under the passenger seat and he has
nice headers on it but burns almost as much oil as gas (doesn't smoke) however going up steep hills he says say press on the gas at 2200 rpm the
engine detonates like crazy, puts the pedal to the floor and detonation stops even without dropping to passing gear.
I went and checked it out for him in the driveway last week and set his initial at about 10 degrees, didn't take note where it was set initially
however way advanced. Revved up the engine and while he has a fuel injection distributor that has no mechanical or vacuum advance his computer is not
giving any advance and will however drop advance with manifold vacuum drop so Map sensor is working at least so guessing he had his initial set at
somewhere around 25-35 degrees. Anyway he's looking for an engine to build, wants me to build and change but I don't se me having time in the near
future. Oil analysis doesn't look good and I suggested picking up a leak down tester and checking, mine is home made and one gauge is toast.
Anyway I want to replace the original 25 year old camshaft, wouldn't mind more power but not at the expense of Valvetrain reliability and detonation.
Also, Falcon engine parts on ebay, any good?
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Bill Dolinsky
Dec 18, 2014, 2:49:23 AM12/18/14
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He doesn't know what he has. Bough it out of Texas I think, at least the 97 tracker toad I bought off him had Texas inspection stickers on it. Twin
beds in the back. Pretty sure 1977. 455 fuel injected with stainless headers, hydra boost if that rings any bells. Both toad and motorhome mostly
cream or off white.
But I think he power timed it and he said at torque converter stall he couldn't get it to detonate so who knows what he had for timing. Like I say the
computer wasn't doing anything and I asked him if he had any info re: setting initial, like jumping pip or whatever but no info but like I said
setting 10 degree initial and reving up Retarded to 2 degrees so his initial must have been cranked. Told him if he couldn't find any info or If it
couldn't be fixed he's looking at $1800 to $3000 for a new fuel injection system. News I don't think he wanted to hear considering he's probably
already ruined his 455. He's retired, has a business selling soap and probably spends more time on it than I get a chance to spend on mine, put his
rear brakes together for him last year,was a challenge bleeding with the master pretty much lower than the wheel cyls on his sloping driveway,
pressure blend from the back to the mc.Put a 4 bag system on it I don't recall seeing on this site and says he doesn't really like it. But way
prettier than mine at the moment. Out of country inspection mechanic wouldn't pass it because of wheather checked tires so trips that summer he just
put the plate from his Lexus on it. Told him he needed brake cables and hoses and wheel cyl and on and on and he eventually agreed with we and
replaced all that stuff.
He wanted to buy my caddy, then my 403. I told him his headers. While they would work on the 403 he would have to make the couplings narrower so
build a 455. Then his awning removed itself from the coach, I kinda feel bad for him because he has a lot invested. He had a house with a couple slide
outs and a Ford V10 for a year or 2 and got the gmc bug, maby I feel sorry for all of US? lol
beds in the back. Pretty sure 1977. 455 fuel injected with stainless headers, hydra boost if that rings any bells. Both toad and motorhome mostly
cream or off white.
But I think he power timed it and he said at torque converter stall he couldn't get it to detonate so who knows what he had for timing. Like I say the
computer wasn't doing anything and I asked him if he had any info re: setting initial, like jumping pip or whatever but no info but like I said
setting 10 degree initial and reving up Retarded to 2 degrees so his initial must have been cranked. Told him if he couldn't find any info or If it
couldn't be fixed he's looking at $1800 to $3000 for a new fuel injection system. News I don't think he wanted to hear considering he's probably
already ruined his 455. He's retired, has a business selling soap and probably spends more time on it than I get a chance to spend on mine, put his
rear brakes together for him last year,was a challenge bleeding with the master pretty much lower than the wheel cyls on his sloping driveway,
pressure blend from the back to the mc.Put a 4 bag system on it I don't recall seeing on this site and says he doesn't really like it. But way
prettier than mine at the moment. Out of country inspection mechanic wouldn't pass it because of wheather checked tires so trips that summer he just
put the plate from his Lexus on it. Told him he needed brake cables and hoses and wheel cyl and on and on and he eventually agreed with we and
replaced all that stuff.
He wanted to buy my caddy, then my 403. I told him his headers. While they would work on the 403 he would have to make the couplings narrower so
build a 455. Then his awning removed itself from the coach, I kinda feel bad for him because he has a lot invested. He had a house with a couple slide
outs and a Ford V10 for a year or 2 and got the gmc bug, maby I feel sorry for all of US? lol
Larry
Dec 18, 2014, 11:27:57 AM12/18/14
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Bill,
IIRC from reading Doc Fromanders book on the BB Cad, if you are going to use a stock cam, the camshaft from the 73' 500 is the best "stock" cam to
use. I'd be inclined to take it out and mic it to see how much wear has taken place. If wear is minimal, get a new set of lifters and put it back in.
Reground Camshafts are called reground for a reason. They basically grind them smaller with an attempt at getting the original profile. Because the
base circle is smaller, it causes problems with lifter preload, so that has to be addressed. If you are going to put in an aftermarket cam, I would
get a cam from either of the two BB Cad distributors. That would be MTS (Maximum Torque Specialities) or "The Cad Company". They have put a fair
amount of R&D into developing cams specifically for the BB Cad motor. Other companies have put most of their efforts into the Chevy BB and SB, Ford
BB and SB and other more common motors out there, and little or none on the Cad 500.
No matter what you do, IMO, you should replace the stock "T" pedestal rocker system with any of the shaft rocker systems that are available from MTS
or CadCO. The stock rocker system is the achiles heal of that motor. Over time, the "T" pedestals and the rockers do not wear square with the rest
of the valve train, putting side pressure on the valves, wearing out valve guides to the extent that eventually the valve will hang, the piston will
strike it and bend a valve. The result can also be bent pushrods, which can fall out of place resulting in a lifter that will pop out of the bore, and
complete loss of oil pressure. Go ahead...ask me how I know this. Knowing what I know now, (10yrs of experience, pulled heads 3 times, towed home
once, drove 3K miles on a bent valve) I would not assemble a 500 for use in my MH unless it had a shaft rocker system. You can choose to go cheap
now, but you will pay for it in the future. I bought a non-adjustable shaft rocker system for my 500. IF I had just redone the heads paying close
attention to valve stem height when the heads were assembled...(by the way, when the head is done correctly, you should be able to put a straight edge
across the top of the valve stems and find no difference in height) a non adjustable shaft system should work fine. But if the heads are original or
reworked by your standard valve jocky machinest, chances are the stem heights are not correct or consistant in height. Knowing this, I would spend the
extra on the adjustable rockers. More money...yes...but the ability to adjust each valve to the correct lifter preload. This is all JMHO and hope it
helps.
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
IIRC from reading Doc Fromanders book on the BB Cad, if you are going to use a stock cam, the camshaft from the 73' 500 is the best "stock" cam to
use. I'd be inclined to take it out and mic it to see how much wear has taken place. If wear is minimal, get a new set of lifters and put it back in.
Reground Camshafts are called reground for a reason. They basically grind them smaller with an attempt at getting the original profile. Because the
base circle is smaller, it causes problems with lifter preload, so that has to be addressed. If you are going to put in an aftermarket cam, I would
get a cam from either of the two BB Cad distributors. That would be MTS (Maximum Torque Specialities) or "The Cad Company". They have put a fair
amount of R&D into developing cams specifically for the BB Cad motor. Other companies have put most of their efforts into the Chevy BB and SB, Ford
BB and SB and other more common motors out there, and little or none on the Cad 500.
No matter what you do, IMO, you should replace the stock "T" pedestal rocker system with any of the shaft rocker systems that are available from MTS
or CadCO. The stock rocker system is the achiles heal of that motor. Over time, the "T" pedestals and the rockers do not wear square with the rest
of the valve train, putting side pressure on the valves, wearing out valve guides to the extent that eventually the valve will hang, the piston will
strike it and bend a valve. The result can also be bent pushrods, which can fall out of place resulting in a lifter that will pop out of the bore, and
complete loss of oil pressure. Go ahead...ask me how I know this. Knowing what I know now, (10yrs of experience, pulled heads 3 times, towed home
once, drove 3K miles on a bent valve) I would not assemble a 500 for use in my MH unless it had a shaft rocker system. You can choose to go cheap
now, but you will pay for it in the future. I bought a non-adjustable shaft rocker system for my 500. IF I had just redone the heads paying close
attention to valve stem height when the heads were assembled...(by the way, when the head is done correctly, you should be able to put a straight edge
across the top of the valve stems and find no difference in height) a non adjustable shaft system should work fine. But if the heads are original or
reworked by your standard valve jocky machinest, chances are the stem heights are not correct or consistant in height. Knowing this, I would spend the
extra on the adjustable rockers. More money...yes...but the ability to adjust each valve to the correct lifter preload. This is all JMHO and hope it
helps.
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
Larry
Dec 18, 2014, 11:36:46 AM12/18/14
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OH yes, as for the FI system on your friends MH, I would either change to one of the newer FI systems out there, or put a stock manifold with a Qjet
back on. After going through the "home brewed" FI upgrade, using Dynamic EFI's EBL, P4 software, and all of the time spent in minipulating fuel and
spark tables etc., I might be convinced to try one of the new "Plug and Play" units that are self learning. Anybody out there tried one of these?
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
back on. After going through the "home brewed" FI upgrade, using Dynamic EFI's EBL, P4 software, and all of the time spent in minipulating fuel and
spark tables etc., I might be convinced to try one of the new "Plug and Play" units that are self learning. Anybody out there tried one of these?
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
gene Fisher
Dec 18, 2014, 12:21:08 PM12/18/14
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READ HERE
http://gmc49ers.blogspot.com/
http://gmc49ers.blogspot.com/
it runs great
more coming , keep in touch
erf
--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
Robert Mueller
Dec 18, 2014, 3:20:47 PM12/18/14
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Gene,
Does installing this kit ($2,500) negate Fisher's Law of GMC mileage of 8-10 miles per gallon? ;-)
VVVVVBG!
Regards,
Rob M.
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
-----Original Message-----
From: gene Fisher
READ HERE
http://gmc49ers.blogspot.com/
it runs great
more coming , keep in touch
erf
Does installing this kit ($2,500) negate Fisher's Law of GMC mileage of 8-10 miles per gallon? ;-)
VVVVVBG!
Regards,
Rob M.
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
-----Original Message-----
From: gene Fisher
READ HERE
http://gmc49ers.blogspot.com/
it runs great
more coming , keep in touch
erf
Ken Henderson
Dec 18, 2014, 3:28:46 PM12/18/14
to gmclist
Bill,
After breaking two rocker pedestals during my round trip to CA last summer,
I second Larry's rocker shaft recommendation. Talking Allstate's RV
Roadhelp service into towing the GMC 384 miles wasn't easy. :-)
Ken H.
Americus, GA
On Thu, Dec 18, 2014 at 11:27 AM, Larry <weid...@wwt.net> wrote:
>
> ...
Larry
Dec 18, 2014, 3:47:47 PM12/18/14
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Mr ERFisher wrote on Thu, 18 December 2014 11:21
WOW, so OK...who's coach is this on?
WOW, so OK...who's coach is this on?
Larry
Dec 18, 2014, 3:49:12 PM12/18/14
to gmc...@temp.gmcnet.org
Larry wrote on Thu, 18 December 2014 14:27
> Mr ERFisher wrote on Thu, 18 December 2014 11:21
> > READ HERE
> > http://gmc49ers.blogspot.com/
> >
> > it runs great
> > more coming , keep in touch
> > erf
>
> WOW, so OK...who's coach is this on?
OH, and who else is running this?
> > READ HERE
> > http://gmc49ers.blogspot.com/
> >
> > it runs great
> > more coming , keep in touch
> > erf
>
> WOW, so OK...who's coach is this on?
gene Fisher
Dec 18, 2014, 4:35:19 PM12/18/14
to gmc...@temp.gmcnet.org
On Thursday, December 18, 2014, Robert Mueller <robmu...@iinet.net.au>
wrote:
wrote:
> Gene,
>
> Does installing this kit ($2,500) negate Fisher's Law of GMC mileage of
> 8-10 miles per gallon? ;-
No change
Same price as Howell on sale
But new parts and no computer
>
> VVVVVBG!
>
> Regards,
> Rob M.
> Sydney, Australia
> AUS '75 Avion - The Blue Streak TZE365V100428
> USA '75 Avion - Double Trouble TZE365V100426
>
>
> -----Original Message-----
> From: gene Fisher
>
> READ HERE
> http://gmc49ers.blogspot.com/
>
> it runs great
> more coming , keep in touch
> erf
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
Bill Dolinsky
Dec 18, 2014, 11:46:17 PM12/18/14
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I know the caddy is the torque king but the price to build with shaft rocker and rering I can buy a 489 rotating assembly for $1450 balanced with new
rods, crank, forged Pistons, harmonic ballancer bearings and rings. Ferrea stainless valves like $180, roller cams cheap in comparison. Peanut port
heads would work fine.
A bit more work but maby I need to rethink this.
rods, crank, forged Pistons, harmonic ballancer bearings and rings. Ferrea stainless valves like $180, roller cams cheap in comparison. Peanut port
heads would work fine.
A bit more work but maby I need to rethink this.
Larry
Dec 19, 2014, 8:58:20 AM12/19/14
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Mild Bill wrote on Thu, 18 December 2014 22:46
> I know the caddy is the torque king but the price to build with shaft rocker and rering I can buy a 489 rotating assembly for $1450 balanced with
> new rods, crank, forged Pistons, harmonic ballancer bearings and rings. Ferrea stainless valves like $180, roller cams cheap in comparison. Peanut
> port heads would work fine.
> A bit more work but maby I need to rethink this.
A 489 what?? If that is a Olds 489 for $1450 with all of the trimmings you mention...sounds to good to be true. Tell us more....
> new rods, crank, forged Pistons, harmonic ballancer bearings and rings. Ferrea stainless valves like $180, roller cams cheap in comparison. Peanut
> port heads would work fine.
> A bit more work but maby I need to rethink this.
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.
Larry
78 Royale w/500 Caddy
Menomonie, WI.
Bill Dolinsky
Dec 19, 2014, 6:32:54 PM12/19/14
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Big block chevy 454 stroked
Dave King
Dec 19, 2014, 7:58:55 PM12/19/14
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But a Chevy won't bolt up to the bell housing on the
Olds transmission and the right side drive shaft
goes through the oil pan and gets hit by the crank.
--
DAVE KING
lurker, wannabe
Toronto, Ontario, Canada
Olds transmission and the right side drive shaft
goes through the oil pan and gets hit by the crank.
--
DAVE KING
lurker, wannabe
Toronto, Ontario, Canada
John Wright
Dec 19, 2014, 10:47:13 PM12/19/14
to GMC Net
Actually a Chevy BB will fit in the GMC and has been done many times. Dave Lenzi has an 8.1 version that is a monster. There is an adapter plate for the transmission bolt up and the drive shaft is close but does not hit the crank.
JR Wright
78 Buskirk Stretch
75 Avion
Michigan
JR Wright
78 Buskirk Stretch
75 Avion
Michigan
Jim Kanomata
Dec 20, 2014, 11:30:21 PM12/20/14
to gmc...@temp.gmcnet.org
Bill,
Listen to what Ken H said about the rocker stand,
Lot of us have had that failure, and your not able to pick up that part
easily at a parts store.
--
Jim Kanomata
Applied/GMC, Fremont,CA
ji...@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
Listen to what Ken H said about the rocker stand,
Lot of us have had that failure, and your not able to pick up that part
easily at a parts store.
Jim Kanomata
Applied/GMC, Fremont,CA
ji...@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
Carey Bryan
Dec 22, 2014, 11:57:45 AM12/22/14
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Bill,
I have waited to post because I am not as qualified as you or the folks who post here on engine topics. However, I have some experience I think I
have that might add a little to the discussion. As you see from the signature block, I bought a coach with a Cadillac 500 (.030 over), rebuilt, with
sequential Accel EFI circa 2002, no mass air sensor, no knock sensor.
The computer control was a case of arrested development. Like Ken Henderson, I suspect that the PO found that the thing ran so well generally that
they left things alone ("I'll get to the power enrichment after this mountain trip to see the grandchildren") and then burned a valve or two. Sold it
to me. I am happy with it, but work still needed to be done. Acceleration enrichment, cold start enrichment, prime squirt, partially blocked
injector (460 Ford Bosch injector), all needed to be tweaked.
Still runs pretty well, but not like a sewing machine. Dreading taking the heads off.
Now, what I did find: It had a "torque cam" (so said the PO). I don't know the particulars, but the engine was built by a Cadillac guru, speculation
has it, the fellow in Soddy-Daisy Tennessee. Quality build, I think. While changing the parameters for the cold start, I saw where just off idle,
the "tip in" timing was retarded quite a bit. I thought I would advance it so it would be like the rest of the table.
Boy, oh boy, it knocked. I had never heard it knock before. I thought it had low compression, but actually it seems that the first tuner got all
knock out of it. I got that advance back out of it pronto, no damage. It knocked worse than my Dad's '62 Chevy Biscayne 235 6 on regular.
I think that you might well do well suppressing knock with the software available to better control things, despite the torque cam. You are a
professional who can solve problems in minutes that takes me months to get some sort of handle on. However, I have that luxury and enjoy it, to each
his own. There are tables out there for the throttle body regime that have been laboriously tweaked for ideal running. I now know that Carbs and
power enrichment circuits are nonlinear (they really dump the gas on WOT) and I have to be careful about full power enrichment with injectors.
I guess really the best solution is to use the BBC. Despite some of the drawbacks, development on that engine has proceeded so far as I can tell, and
the power available with the right cheap components is staggering. Especially since I see them on air boats and used as marine engines. I plan to put
the shaft rocker system on the 500. It's starting to look like we 500 aficionados are nothing more than a cult who are willing to pay the price for
performance and reliability.
I post this for what it's worth.
Respectfully submitted,
Carey
--
Carey from Ennis, Texas
78 Royale, 500 Cadillac, Rance Baxter EFI.
I have waited to post because I am not as qualified as you or the folks who post here on engine topics. However, I have some experience I think I
have that might add a little to the discussion. As you see from the signature block, I bought a coach with a Cadillac 500 (.030 over), rebuilt, with
sequential Accel EFI circa 2002, no mass air sensor, no knock sensor.
The computer control was a case of arrested development. Like Ken Henderson, I suspect that the PO found that the thing ran so well generally that
they left things alone ("I'll get to the power enrichment after this mountain trip to see the grandchildren") and then burned a valve or two. Sold it
to me. I am happy with it, but work still needed to be done. Acceleration enrichment, cold start enrichment, prime squirt, partially blocked
injector (460 Ford Bosch injector), all needed to be tweaked.
Still runs pretty well, but not like a sewing machine. Dreading taking the heads off.
Now, what I did find: It had a "torque cam" (so said the PO). I don't know the particulars, but the engine was built by a Cadillac guru, speculation
has it, the fellow in Soddy-Daisy Tennessee. Quality build, I think. While changing the parameters for the cold start, I saw where just off idle,
the "tip in" timing was retarded quite a bit. I thought I would advance it so it would be like the rest of the table.
Boy, oh boy, it knocked. I had never heard it knock before. I thought it had low compression, but actually it seems that the first tuner got all
knock out of it. I got that advance back out of it pronto, no damage. It knocked worse than my Dad's '62 Chevy Biscayne 235 6 on regular.
I think that you might well do well suppressing knock with the software available to better control things, despite the torque cam. You are a
professional who can solve problems in minutes that takes me months to get some sort of handle on. However, I have that luxury and enjoy it, to each
his own. There are tables out there for the throttle body regime that have been laboriously tweaked for ideal running. I now know that Carbs and
power enrichment circuits are nonlinear (they really dump the gas on WOT) and I have to be careful about full power enrichment with injectors.
I guess really the best solution is to use the BBC. Despite some of the drawbacks, development on that engine has proceeded so far as I can tell, and
the power available with the right cheap components is staggering. Especially since I see them on air boats and used as marine engines. I plan to put
the shaft rocker system on the 500. It's starting to look like we 500 aficionados are nothing more than a cult who are willing to pay the price for
performance and reliability.
I post this for what it's worth.
Respectfully submitted,
Carey
--
Carey from Ennis, Texas
78 Royale, 500 Cadillac, Rance Baxter EFI.
James Hupy
Dec 22, 2014, 12:10:24 PM12/22/14
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I have had various Cadillacs over the years. 1949, 2 1951's, a 1977 SDV, a
1961 CDV, and presently have a baby 500 engine sitting on an engine stand
in my shop. It has the prone to fail trunnion pin rocker system like Ken
had on his 500. Before you do anything else like after market camshafts or
valve springs, do yourself a huge favor and eliminate those trunnion pin
style rocker stands. Either use a stud mounted chev type system, or a full
rocker shaft system. There are systems out there that have torrington
roller bearings and roller tips. Those are very $$$$$. and unnecessary for
the revs we turn in a GMC. But, it is your money. Spend it like you had it.
Jim Hupy
Salem, OR
78 GMC Royale 403
1961 CDV, and presently have a baby 500 engine sitting on an engine stand
in my shop. It has the prone to fail trunnion pin rocker system like Ken
had on his 500. Before you do anything else like after market camshafts or
valve springs, do yourself a huge favor and eliminate those trunnion pin
style rocker stands. Either use a stud mounted chev type system, or a full
rocker shaft system. There are systems out there that have torrington
roller bearings and roller tips. Those are very $$$$$. and unnecessary for
the revs we turn in a GMC. But, it is your money. Spend it like you had it.
Jim Hupy
Salem, OR
78 GMC Royale 403
Carey Bryan
Dec 22, 2014, 8:48:35 PM12/22/14
to gmc...@temp.gmcnet.org
Thanks, Jim. Will put a shaft rocker system on it. Will wait until the valve job to see if adjustable will be required. The local machine shops
will give you a great job. If you want it on time, that's problematic.
will give you a great job. If you want it on time, that's problematic.
Bill Dolinsky
Dec 23, 2014, 8:37:43 AM12/23/14
to gmc...@temp.gmcnet.org
Yeah, no decision yet.
Re: fuel injection. I did Megasquirt II Extra on the small block chevy Porsche 944. My first tune was the best, ran rank! Tried to get in a little
economy
And have never got a tune as nice. So much you can change.
Consideration for the BBC, better head lot clamping, Valvetrain and oil system, cheaper, nicer parts. And have built a few of them.
I have one in my ski boat and built a 489 for my airboat, just shouldn't have sold some of my parts. :(
Shaft rocker for the caddy, yeah probably a necessity in a reliable build. Price really not bad however I compare to BBC. Personally prefer bushed
rockers over Torrington bearing rockers in applications that get occasional use or a moisture laden environment like a boat. I put a set of stainless
rockers on my boat and 3rd season on them I was doing a 5500 rpm pass to impress the girls when one or more seized up, could have been brand but no
problems on Porsche so blame environment more.
Re: fuel injection. I did Megasquirt II Extra on the small block chevy Porsche 944. My first tune was the best, ran rank! Tried to get in a little
economy
And have never got a tune as nice. So much you can change.
Consideration for the BBC, better head lot clamping, Valvetrain and oil system, cheaper, nicer parts. And have built a few of them.
I have one in my ski boat and built a 489 for my airboat, just shouldn't have sold some of my parts. :(
Shaft rocker for the caddy, yeah probably a necessity in a reliable build. Price really not bad however I compare to BBC. Personally prefer bushed
rockers over Torrington bearing rockers in applications that get occasional use or a moisture laden environment like a boat. I put a set of stainless
rockers on my boat and 3rd season on them I was doing a 5500 rpm pass to impress the girls when one or more seized up, could have been brand but no
problems on Porsche so blame environment more.
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