My speedmasters, ( not the cnc version) poured 63cc with ferrea valves.
My stock stroke mild 360 build ;)
- Thread starter mopardude318
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AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Just for perusal;
Several guys on FABO, myself included are running, or have run, near or at 200psi with aluminum heads.
I have never run anything but 87E10 at 930ft elevation, and a minimum cooling system temperature of 205*F. My engine was built in year 1999, and has over 100,000 miles on it. The Scr has been as high as 11.3 with a 292/292/108 Mopar cam. and as low as 10.7 with a 223*.050 Hughes cam. Currently running 10.95 with a Hughes 230* cam. I run a A833 and 3.55s at 3650 pounds. Goes like a scalded leopard.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Yes but the loss is less than 1.5psi per degree. so you ain't gonna get much, not the way to go .
The NP435 was produced with at least two different ratios;
4.78-2.39-1.37-1.00 splits of .50-.57-.73
6.69-3.34-1.79-1.00 splits of .50-.54-.56
That granny gear is NOT synchronized, which means it takes a trick to get back into it, on the downshift. Without it, second gear might be a bit of a stretch......
Corrected to a 24" tire, the second gears math to
4.10 x2.39 x24/33=7.13, and
4.10 x3.34 x24/33=9.96
OOPs I guess not,lol. At least not for the engine you are building.
mopardude318
Well-Known Member
ok so in summary, what does that mean? What are ya trying to tell me? Lol.
Too much of an engine for a slow shifting truck trans?
Not sure which gear set I have, I should know, my brother and I rebuilt the damned thing.
Might be the lower geared unit. Think it was more common.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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It means your gearing should be fine, in at least the first two gears.
dirty white boy
50 yr old Juvenal delinquent
guessing at a intake closing point of 63.5... alta run good on pump swill!
Static compression ratio of 10.5:1.
Effective stroke is 2.80 inches.
Your dynamic compression ratio is 8.43:1 .
Your dynamic cranking pressure is 174.03 PSI.
Your effective boost compression ratio, reflecting static c.r., cam timing, altitude, and boost of 0 PSI is 8.39 :1.
V/P (Volume to Pressure Index) is 149
i like this calculator here for static compression, very complete!
Calculating Cubic Inch Displacement & Compression Ratio
Static compression ratio of 10.5:1.
Effective stroke is 2.80 inches.
Your dynamic compression ratio is 8.43:1 .
Your dynamic cranking pressure is 174.03 PSI.
Your effective boost compression ratio, reflecting static c.r., cam timing, altitude, and boost of 0 PSI is 8.39 :1.
V/P (Volume to Pressure Index) is 149
i like this calculator here for static compression, very complete!
Calculating Cubic Inch Displacement & Compression Ratio
mopardude318
Well-Known Member
Right on thanks! turns out I do have the lower geared trans, more common.
MOPAROFFICIAL
Oogliboogli
Yeah ive run 8.89 dynamic too, and so on n so forth. It's california pump 91, its garbage and I'm just putting caution out there to the op.
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MOPAROFFICIAL
Oogliboogli
my thought is ..if you have to retard it, it's the wrong cam. It will hurt the whole idea of the build =torque. No biggie ...if it seems like it's not going to work then you can always change it later. Sometimes you just have to find out for yourself... and that's okay. I just get sick of the people in their blanket statement builds where they get it to work on 93 or corn and then assume that it will work on 91 too. Like the overconfidence some people have from winning one battle... gets old.
If the numbers pan out like dirty white boy posted, then you should be just fine with room even.
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I ran 205 PSI with 915 iron heads on a stock stroke 360 with the 508 cam. It "did not like" straight 93 super, so I always had a spike of about five gallons of 114 Cam2. When I went to the track, I filled up with it. "Back then" it wasn't but about 3.75 a gallon.
dartfreak75
Restore it, Dont part it!
Nice build! That will be one fun truck!! Keep us updated i like it!
mopardude318
Well-Known Member
My other question, getting ready to order a carb. Really wanna try the Holley Street Demon, with composite bowls.
625 or 750?
625 or 750?
dirty white boy
50 yr old Juvenal delinquent
750!
If possible, use the thick Edelbrock carb gasket. There around .333 thick or so. This could cause a hood height issue. The gasket is thick for heat insulation. Very well worth it.
mopardude318
Well-Known Member
Installed the SpeedMaster heads, using their studs I torqued to 95 ft lbs. Minor issue with the washers spinning while torquing so sanding the bottom of ‘em worked great. Lol
The Pioneer brand harmonic balancer slid easy onto the crankshaft snout. Not good so I got one from Blueprint Engines, it pressed on with an installer tool. Thanks @Johnny Mac for that.
Fuel pump is a 10 yr old Holley Strip mechanical.
now the shameful part, I’m reusing the stock pushrods and rocker arms...for now. :O
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It is what it is sometimes. And this is not the end of the world.
mopardude318
Well-Known Member
Well, ran into a problem...trying to bolt on the intake manifold, It doesn’t fit. Lol
Bolt holes don’t line up....With a gasket, without a gasket, they just don’t line up.
Its a brand new rpm air gap.
I then tried a stock iron manifold, same thing.
New uncut SpeedMaster heads...
Could it be that maybe the machine shop took too much off the deck?
I remember asking him from the beginning, he couldn’t tell me an exact number.
Bolt holes don’t line up....With a gasket, without a gasket, they just don’t line up.
Its a brand new rpm air gap.
I then tried a stock iron manifold, same thing.
New uncut SpeedMaster heads...
Could it be that maybe the machine shop took too much off the deck?
I remember asking him from the beginning, he couldn’t tell me an exact number.
Yup!
Oldiron440
Well-Known Member
Probably have to cut the manifold but how far of is it?
Bobzilla
Well-Known Member
With the intake sitting in place on the heads, can you see if the intake bolt holes IN THE HEAD are too high or too low?
If too low, having the intake flanges machined properly will work.
If too high, you may be able to use thicker intake gaskets.
Post a picture looking into an intake bolt hole.
mopardude318
Well-Known Member
Off enough to where I can’t get any but one bolt started.
Bolt holes are too low.
...didn’t wanna have to machine the intake, Or heads, wouldn’t they then be limited to this engine only?
Does this happen often when a block is machined? I thought very little is taken off the deck to where there would be no fitment issues. :0
yellow rose
Overnight Sensation
There is no such thing as one intake fits just one engine. Machine the intake. There probably isn’t another intake that will fit what you have.
If you set the intake manifold on without a gasket and the holes line up, tell the machine shop to get a clean surface on the intake face and THEN take the FULL gasket thickness of whatever gasket you use.
If you set the intake on without a gasket and the holes are not lined up, you take a clean cut, the gasket thickness and how much the hole is off as a percentage of the gasket thickness.
So, let’s say you put the intake on and half the bolt hole is lined up. That’s a clean cut, the gasket thickness and half again the gasket thickness.
So...let’s say your gasket is .040 thick. In the above example of the intake lining up perfectly with NO gasket, you take a clean cut and .040 off the intake.
In the above example of the intake being half a hole high, you take a clean cut, .040 for the gasket and and other .020 because you had half the hole showing.
The last example would be if you set the intake on with THE gasket and you are half a hole off, you take a clean cut and half the gasket thickness, which would be .020 if you use .040 gasket.
EDIT. This happens all the time.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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But before you machine anything, remove the gasket locating pins from the china wall to make sure they are not elevating your intake.
After machining the intake,check the clearance at the china-wall again, there is a chance you might have to mill the intake front and rear as well.
When I built my 360 I had the decks milled so that the KB107s popped up out of the holes .007ish from the .012below deck they fell in at; so that was like .019. My Rpm AG fit "OK "without machining, using FelPro .039 gaskets. I did NOT gasket match.
After machining the intake,check the clearance at the china-wall again, there is a chance you might have to mill the intake front and rear as well.
When I built my 360 I had the decks milled so that the KB107s popped up out of the holes .007ish from the .012below deck they fell in at; so that was like .019. My Rpm AG fit "OK "without machining, using FelPro .039 gaskets. I did NOT gasket match.
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mopardude318
Well-Known Member
These chinese stamped steel covers with my poser stickers, fit like ****, probably won’t use them. Would like a polished set of MP’s if I can find ‘em.
Holley street demon 750, with a 1” wood spacer. I put one of those wood spacers on my other engine and it really keeps the manifold heat from the carburetor. I got the distributor from member TrailBeast who also installed the FBO plate for me. Thanks.
Maybe I can do the break in, in a couple weeks. Gotta finish installing the front Dana 60. Other than that, I think I’m ready.
...wont be surprised if this POS blows up on me or something happens. I’m almost expecting it, from the way this build has been going. Lots of little nuisances I went through on this damn thing.
this will be my 4th break-in under my belt. Lol
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