High Performance Big Block Cadillacs
November 20, 2017, 10:08:23 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
News: SMF - Just Installed!
 
   Home   Help Login Register  
Pages: 1 [2]
  Print  
Author Topic: 500 CI Mudder  (Read 19071 times)
dave brode
C5
*****
Posts: 1074


Best of 11.66, 113.96, 1.59 sixty


« Reply #15 on: December 26, 2009, 04:09:09 PM »

Hey Brode,

When I built the motorhome motor, I bought Comp Cams 255DEH cam and their
281-16 springs.  I looked at the springs, thought they looked familiar.  Dug out
a large box of SBC springs from the old days.  Same wire diameter, same no.off 1/3
of coils and same free height.  Only difference was they cut 1/3 off the damper to
clear the guide.  On my spring tester, they had the same tension.  Since the
installed spec they called for would have caused coil bind, I reduced it to a more
reasonable spec for a 3K max motor and saved a bunch of shims.  Worked fine.
Those yahoos they have working the phonesdon't want to waste their time
talking to anyone who doesn't have a Chevy racecar JMHO

Gary Kosier

LOL. And since most normal sbc springs stack in at 1.700-1.750", you need a pile of shim to make them work. The best thing I really [don't]  like about comp is they use 1.73-1 for the rocker ratio. Poor unknowing fellows don't have a clue that their comp cam has way less lift than advertised.

Dave
Logged

3960 lb '71 C-10. 11.7-1 CR 514". PEP I beam rods floating MTS 18cc dish Probes, Elgin solid cam, home ported heads, MTS 2.19/1.84", Potter/Probe shaft rockers, edel 2115, 4781 850. Switch-pitch TH400, 12" 1800/3200 Tri-Shield convertor, 4.30 gears. Best so far of 11.66, 114.8 mph and 1.59 sixty
MUDCADDY
C1
*
Posts: 14


« Reply #16 on: December 27, 2009, 07:18:58 PM »

MOTOR IS IN THE GARAGE !!!!!!
Will the springs MTS sells for use with the #15 cam drop right in Huh??
I'm going to have the heads off so cutting down the tops of the guides won't be tough but I don't have a seat cutter at my immediate disposal.
I'm hoping to have the motor on the stand and apart by next weekend....I'm curious what kind of shape the cylinder walls and crank are in. I'm hoping for a quick re-ring with a hand hone and some new bearings.
I'm going to resist the temptation to buy pistons to try and bump the CR.
I know I'll lose some bottom end with the #15 cam and could use more compression but I'm trying to go easy.
The last "RACING MOTOR" I ran had .790 lift with 345lbs of spring on the seat !!!!!
Logged
dave brode
C5
*****
Posts: 1074


Best of 11.66, 113.96, 1.59 sixty


« Reply #17 on: December 27, 2009, 08:06:59 PM »

< Will the springs MTS sells for use with the #15 cam drop right in Huh??

Dunno. I suspect that they have something that would.

> I'm going to have the heads off so cutting down the tops of the guides won't be tough but I don't have a seat cutter at my immediate disposal.

Any good machine shop *should* have one.

> I'm hoping to have the motor on the stand and apart by next weekend....I'm curious what kind of shape the cylinder walls and crank are in. I'm hoping for a quick re-ring with a hand hone and some new bearings.

If there is ANY ridge, I would cut it out with a ridge reamer. If not, the new ring will bump against the ridge = not good. Some parts store rent them.

> I'm going to resist the temptation to buy pistons to try and bump the CR.

A custom domed piston would be required for higher cr with your heads anyway. Using factory parts, the only way to get higher and still have pump gas compression is with 76cc heads and 1970 only pistons. All 71-76 are advertised at 8.5-1. The 71-73 are 76cc and huge dish. 74-76 are like yours, the 120cc head and very small dish apx 2.5" diameter. 76cc heads on your pistons = 12.5 to one or so. Not wise.

Dave

p.s. - fwiw;

I would use plain cast rings on an old used bore, not moly. I like a dingle ball hone better than a cheap 3 stone. I would sand sides of rods a bit for at LEAST .025" side clearance. As is, they'll be very tight. Imo - Rod bearing clearance at no less than .002", prefer .0025". Mains at no less than .0025", prefer .003 to .0035". If you have tight clearances and pound it, it'll probably blow up.
« Last Edit: December 27, 2009, 08:11:38 PM by dave brode » Logged

3960 lb '71 C-10. 11.7-1 CR 514". PEP I beam rods floating MTS 18cc dish Probes, Elgin solid cam, home ported heads, MTS 2.19/1.84", Potter/Probe shaft rockers, edel 2115, 4781 850. Switch-pitch TH400, 12" 1800/3200 Tri-Shield convertor, 4.30 gears. Best so far of 11.66, 114.8 mph and 1.59 sixty
MUDCADDY
C1
*
Posts: 14


« Reply #18 on: December 28, 2009, 05:19:15 AM »

AHHH...the old black bearing syndrome.....I wouldn't imagine anyone sells +.001 bearings for caddy like they do Chebies.

I have a ridge reamer, ball hone and stuff here.....

I know the MTS#20 kit includes a spring which requires the lower OD of the guide be cut straight.

I'm going to do a leakdown before pulling the heads.......started to do a compression test but it was too cold out in the back of my truck......maybe if it tests good and the walls are good with little ridge I leave the rings for next time.....



Snow melted down for now......my mudder in waiting......


Logged
dave brode
C5
*****
Posts: 1074


Best of 11.66, 113.96, 1.59 sixty


« Reply #19 on: December 28, 2009, 06:02:35 PM »

MUDCADDY,

You mean +.001" over [as in more bearing clearance, or -.001", as in less bearing clearance? I doubt that you'll find either.

Fyi - several of us here and elsewhere have found that a std crank polished to low side of spec, and rod big ends near the upper end of spec will give .0025" or so rod. The mains usually come in around .003" with the crank polished to low. Depends on main bores though, but usually.....

Heck, by the time you buy bearings and all the gasket, can almost buy the rebuild kit from northern. I haveused those and the Victor head gaskets worked fine for me. The have a felpro upgrade. Only thing is, you will not get an oil pump gasket in the re-build kit gaskets. Pisses me off, as you get an oil pump gasket in a felpro front cover gasket set. MTS sells the pum gaskets seperately. Make sure the pump gasket is no thicker than .008" or so if you get one elsewhere. Thicker = too much clearance on the pump gears.

Dave
Logged

3960 lb '71 C-10. 11.7-1 CR 514". PEP I beam rods floating MTS 18cc dish Probes, Elgin solid cam, home ported heads, MTS 2.19/1.84", Potter/Probe shaft rockers, edel 2115, 4781 850. Switch-pitch TH400, 12" 1800/3200 Tri-Shield convertor, 4.30 gears. Best so far of 11.66, 114.8 mph and 1.59 sixty
MUDCADDY
C1
*
Posts: 14


« Reply #20 on: December 28, 2009, 08:28:40 PM »

Yes.....001 oversize bearings are available for the Chevys....I'll mike crank and bearings and see what I get.... I don't plan on pushing it too hard...... Shocked Shocked Grin Grin Shocked
Logged
ST Dog
C4
****
Posts: 499



« Reply #21 on: December 29, 2009, 11:11:08 PM »

For the rods you can get +1 http://www.rockauto.com/catalog/x,carcode,1025378,parttype,5212

Egge claims to have +1 and +2 rod bearings and +1 mains.
http://www.egge.com/site/?d=48&dt=1&SubCategoryId=11&make=CADILLAC&year=1970&rpp=10
Logged

MUDCADDY
C1
*
Posts: 14


« Reply #22 on: December 30, 2009, 04:56:26 AM »

I think...I think..... that's all undersized.....like if you had a crank you had to polish a little extra to get rid of an imperfection but wanted stock clearances.... I could be wrong but what would you do with .020.....030.....040.....OVER BEARINGS Huh???
Logged
ST Dog
C4
****
Posts: 499



« Reply #23 on: December 30, 2009, 07:22:35 AM »

Yeah, all thicker for a smaller journal.
Just used the naming Egge used.

That's what you'd want on a used crank though.
Logged

dave brode
C5
*****
Posts: 1074


Best of 11.66, 113.96, 1.59 sixty


« Reply #24 on: December 30, 2009, 04:11:39 PM »

I think...I think..... that's all undersized.....like if you had a crank you had to polish a little extra to get rid of an imperfection but wanted stock clearances.... I could be wrong but what would you do with .020.....030.....040.....OVER BEARINGS Huh???

they are UNDER, not oversized. As in LESS clearance. 10, 20, 30 are also UNDERsized. As in, crank ground smaller. They may make .001" oversized for some engines [for MORE clearance with a std crank], but I doubt for caddy. 
« Last Edit: December 30, 2009, 04:24:04 PM by dave brode » Logged

3960 lb '71 C-10. 11.7-1 CR 514". PEP I beam rods floating MTS 18cc dish Probes, Elgin solid cam, home ported heads, MTS 2.19/1.84", Potter/Probe shaft rockers, edel 2115, 4781 850. Switch-pitch TH400, 12" 1800/3200 Tri-Shield convertor, 4.30 gears. Best so far of 11.66, 114.8 mph and 1.59 sixty
dave brode
C5
*****
Posts: 1074


Best of 11.66, 113.96, 1.59 sixty


« Reply #25 on: December 30, 2009, 04:21:38 PM »

Repeat;


I would sand sides of rods a bit for at LEAST .025" side clearance. As is, they'll be very tight. Imo - Rod bearing clearance at no less than .002", prefer .0025". Mains at no less than .0025", prefer .003 to .0035". If you have tight clearances and pound it, it'll probably blow up.

Some of us know and listen to a wise fellow that goes fast with caddy engines, and has had none blow up. He says:

A stock std crank polished to close to the low side of the spec, and rod and main bores near the high side of the spec will normally give perfect running clearances. Those being noted above. I have found that to be true from my own expericence too. I have had none blow up.

Suit yourself, but $1 says that if the crank is pretty enough for just a polish, undersized bearings will be a mistake.

Fwiw, if I had a choice between .002" and .003" rod clearance, I would choose .003" [prefer .0025"]. If I had a choice between .0025" and .0035" main clearance, I would choose .0035" [prefer .003" to .0033"]

A rule of thumb is 1 thou for every inch of journal size. Rods are 2.5", mains are 3.25".

I would stick a screw driver between the pairs and see whatfer feeler guage will go in before you pull it apart. See above.

Dave

Logged

3960 lb '71 C-10. 11.7-1 CR 514". PEP I beam rods floating MTS 18cc dish Probes, Elgin solid cam, home ported heads, MTS 2.19/1.84", Potter/Probe shaft rockers, edel 2115, 4781 850. Switch-pitch TH400, 12" 1800/3200 Tri-Shield convertor, 4.30 gears. Best so far of 11.66, 114.8 mph and 1.59 sixty
MUDCADDY
C1
*
Posts: 14


« Reply #26 on: January 03, 2010, 04:35:38 PM »

WELL...I'm no further ahead on the Caddy project......the weekend long snow storm prompted me to keep our two year old son home instead of sending him down to visit Grandma like I usually do on my wife's Sunday working....gives him time with the family and me time to work in the shop.
We went out to pull the tranny off the motor but within 2 minutes he was wrist deep in a waste oil pan....NOPE......NOT TODAY !!!!
I DID get a chance to start the Nitro Harley for my first time on Friday !!!!
I need to make some alterations to my pit stand so the bike can't move as much but it ran thru about a 1/2 gallon of methanol.
I was going to throw some Nitro in the tank after I knew the motor was warmed up and circulating oil. The rickety stand and the fact that I was in an almost sealed off garage by myself made me think differently. You really need another set of eyes and hands when you run Nitro.
I had visions of the bike shooting off the stand and trying to smash thru the shop wall...maybe next week.
The link below shows my homebuilt alky idle system including a short crappy phone video clip.
http://www.nitrocycles.net/html/alky_idle_system.html
Logged
Pages: 1 [2]
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.20 | SMF © 2013, Simple Machines Valid XHTML 1.0! Valid CSS!