Guess my horsepower.

[C Body Bob]

Ok just playing here. I picked up my Diplomat from Gary’s (Wollfen) shop Saturday. As soon as I can get an open bay I plan to dive into it hard. I have a lot of parts & want to use what I have which means it will be a budget build. So here’s what I have
77 Dodge truck 360 ( I’ll just hone the cylinders, have the crank checked & just a basic re-ring & gasket. 8.0-8.2 compression
Stock 360 heads with the 1.88 intake valve. Performance 3 angle valve job & pocket port work OR ——-
Same heads & have the 2.02 NOS intake valves I have installed & said valve job with a little pocket porting. Might cut heads to pick up a little compression.
I have a NIB Lunati hyd cam/lifter .480 lift 230 advertised duration (1800-5500)
Edelbrock dual plane Performer RPM intake
72 Stock 360 C body oil pan
MOPAR performance windage tray
Stock new Melling oil pump & pick up
Used but good B body headers I think 1.5 tubes. (Swap meet score)
Several carbs to pick from but here’s the two I’m leaning towards
1 650 square bore Holley mechanical secondaries & double pumper
2 750 Holley vacuum secondaries double pumper came off a AMC 390 Javelin.
New MSD Pro Billit dizzy. (no vacuum Advance)
I have aluminum roller & steel non roller adjustable rockers but would like to stay with Stock rockers
Ofcourse I’ll work with machine shop on some of this.
My goal is 325-335 horse.

 

[1978 NYB]

I believe you can get there if you bump the CR up a bit.

 

[C Body Bob]

I believe you can get there if you bump the CR up a bit.

Yea I might talk with the machinist about a block deck & head cut. Doubt that will pick up enough to be worth it. I’ll see what he thinks.

 

[max1196]

That stock piston is 100 thou below the deck, have that talk with the machinist.

 

[CBODY67]

Deck the block and get the heads down to min CC, just to make sure where everything is at.

Use Chrome-Moly rings and do NOT hone the cylinder walls. My machine shop operative claims the c-m rings need a smoother cylinder wall to work with, so the "no hone" orientation works well with them. A used car broker friend did that on a budget rebuild of his 454 C-30 car hauler and I heard no negative comments about the c-m/no hone situation.

Leave the valve size at 1.88 and work on port matching and port flow. The larger valves might end up shrouding themselves against the cyl walls a bit, which would hinder ultimate "assembled" flow. Pay more attention to the exhaust ports as they are weaker in performance than the intake ports, typically.

Intake manifold choice is good. Why the dbl-pumper/man secondary carb orientation? Why the no vac advance distributor? Just curious. Smaller cfm might be advisable, provided the secondaries on the 780 would open fully at WOT.

You mentioned nothing about a smaller/looser OEM torque converter with that wilder cam? Just the normal 4bbl HP OEM upgrade would probably be fine. Chrysler had "low-stall" and "high-stall" specs in the same converter diameter (typically had stick-on labels for such). "High-stall" sometimes crossed with a normal Slant Six "low-stall" converter. What axle ratio/tire size?

I know that everybody likes to talk "horsepower", but a lower horsepower motor with more low-to-midrange torque might actually work better, especially if it's a "torque motor that rpms". "Responsive" power in the normal driving range rather than banzai top end rush, so to speak.

Just some thoughts,
CBODY67

 

[BigblueC]

Since there's talk of port work do any of you know anything about the "extrude hone" stuff. I saw this on youtube a while back and thought it was interesting. I really haven't looked too much into it though since I have no need for it right now.

 

[70bigblockdodge]

You know their is no such thing as chrome-moly rings. They are chrome, molybdenum, and just plain iron, all referring to the face material or coating on a iron ring.
Chrome-moly steel alloy is so hard it would never seat, secondly it will become brittle with heat and pressure, shattering into alot of little pieces. This is why you need to have a professional weld your chrome-moly cage in your car to prevent overheating of the joints and making them brittle.
Plain iron rings used in most cars are good for just about everything except high speed and heat.
Molybdenum impregnated rings add strength and oil retention, on the ring, to help with speed. Downside is they will hold dirt with the oil and scratch and scuff your cylinder walls.
Chrome rings are durable and resist dirty conditions well. Because the chrome is so dense and hard, more wear will end up on the cylinder wall.
Molybdenum rings are best for street and strip car just change your oil.
All that jibberish out of the way. Bob, you will be lucky to make 275 with those junk heads. Sorry for the honesty but late 70s sbm are the worst heads. I would shake the bushes to find some late 80s high swirl heads or just put Magnum heads on even though they are most likely cracked will never leak water.
I believe there is a set of the ones like you have, that are very heavily ported for sale on FABO for a long time and the flow bench numbers on them are only as good as OOTB Edelbrock heads.

 

[CBODY67]

The chrome-moly upper piston ring is a chrome ring with a strip of moly embeded into it. It's visible. A hybrid sort of chrome ring that was used by OEMs and others to keep some lube in the upper ring area under extreme conditions.

These rings pre-dated the later "plasma-moly" rings of the '80s. I believe those are the "moly" rings you're referring to.

The Chrysler order guides stated, as I recall, that the HP engines had such chrome-moly rings in them into the middle 1970s, or later. "Police-spec" engines, included. Just going on the literature.

Extrude Hone is a means to get to parts of the ports which normal porting tools can't reach, as I understand it. In the dirt track racing area, there were the Brezenski-ported intakes and such, which were used in the classes where you HAD to run OEM manifolds. Brezenski would hole-saw the runners to they could get porting tools in to those areas to "hog things out", so to speak. When done, they'd weld the hole-sawed plugs back into the manifold, then refinish it to appear "untouched". Still stock parts, but with much better flow.

A semi-viscous material is forced through the ports to abrade and "hone" the surfaces in a manner which was not otherwise possible. A "clean" appearance of the surfaces, which is consistent throughout.

The previously-observed issue with port finish is that it needs to have a bit of roughness to it. Earlier attempts to "polish" it looked neat, but it was later determined, after laminar port flow was discovered, that the slick finish resulted in more laminar break-outs, which caused more flow detriments than benefits. Kind of like how the round ports were supposed to be better than rectangular ports, until flow benches became more affordable by more engine shops and a round port was typically shown to flow the same as or less than the prior rectangular ports.

Leave the finish more rough than polished. Which can also ensure that any fuel droplets will be broken-up and return into the general air flow, too. There is some literature on this subject. Possibly even in the Mopar Perf Race Manuals?

Respectfully,
CBODY67

 

[65sporty]

I put your combo into my desktop dyno and it's suggesting 375 hp with the small heads and 750 carb. It would get closer with actual head flow numbers. Dave's number may be closer.

 

[65sporty]

Since there's talk of port work do any of you know anything about the "extrude hone" stuff. I saw this on youtube a while back and thought it was interesting. I really haven't looked too much into it though since I have no need for it right now.

This has been around for a while, guy's running the FAST class muscle cars would use in on exhaust manifolds and other things

 

[BigblueC]

This has been around for a while, guy's running the FAST class muscle cars would use in on exhaust manifolds and other things

Any idea how it compare to the average mild port/polish jobs?

 

[65sporty]

Any idea how it compare to the average mild port/polish jobs?

Hot Rod did a story on it when it was first out, if I remember right it doesn't remove large amounts of material just creates a smooth finish. Takes away the rough as cast finish. If you want larger ports that work needs to be done first by hand.

 

[C Body Bob]

I put your combo into my desktop dyno and it's suggesting 375 hp with the small heads and 750 carb. It would get closer with actual head flow numbers. Dave's number may be closer.

WOW , yea I’m pretty sure it won’t make that. I’m pretty confident on the 325. My 318 i ran in The BEAST was a similar build with a smaller cam & it made 275-285. I ran 72 J heads on it. All I did was lap the valves. Install DC springs & bolted them on the stock 69 318 Block. 8.0 compression. I didn’t know there was any difference in the 360 LA heads. Untill the 86 & later swirl heads. From what Ive read about them they don’t rev hard & high due to the 1.72 valves. Guys put 1.88 in them to get them to breath a bit more. I’ve never run a set though. Just what I’ve read. I have a set of J heads. That’s what I plan to use anyway. I actually want the low compression so I can run 89-92 octane. I can’t do anything about the piston down in the hole. That’s just the way 360’s are & im not spending a bunch to bore it & new pistons. So it is what it is. As far as the 2.02 valves & shrouding The 4 inch bore will be fine with that. Thats the size the Eddy heads have & most of the other aftermarket heads. Some Magnum based heads have 1.92. As far as rings. I was always told to use iron rings on a re-ring job. Because they are durable since the bore is no longer true. That’s what I’ve always done. I need to download that Desktop Dyno. I had Camquest & use to play around with it. It gave out some pretty high numbers too though. One of the things I do is look at what power the crate Motors are at & what parts they have in them. Several years ago MOPAR Performance advertise a stock 360 with an Eddy intake. 9.0 compression , 1.88 valve heads. They claimed 320 horse. I’ll have less compression & ring seal but a lot more cam & 2.02 valves with pocket porting. My engine should be 8.2 compression. My buddy is trying to get me to go BIG BLOCK geez that a lot of work to shove that in an M body

 

[70bigblockdodge]

Bob, there are 2 different LA swirl heads. I think casting numbers 302 and 308 respectfully the 308s have the 188 intake valve and 340/360 sized intake ports. I cleaned up the heads on my BIL Little red express they are a mess, very poor casting quality control. I removed a rather large amount of material just to get the bowl area to not look like a washer under the valve. Definitely not the finest hour from the foundry. I'm sure the reject bar was pretty low when your hours from going out of business.
I can understand the low buck scrounged up part allure, I have 2 such mutants here. One runs like a scalded gorilla, the other is a wet sponge. Both are mid 8:1 run on junk gas, use no oil and return reasonable mileage. I'm still sticking to my 275 number unless you change heads then I will agreed with your 325 number. Use the 202 valved heads you need all the help you can get. Let's hope they can get you to 300 and 100 mph trap speed in the 1/4

 

[C Body Bob]

Bob, there are 2 different LA swirl heads. I think casting numbers 302 and 308 respectfully the 308s have the 188 intake valve and 340/360 sized intake ports. I cleaned up the heads on my BIL Little red express they are a mess, very poor casting quality control. I removed a rather large amount of material just to get the bowl area to not look like a washer under the valve. Definitely not the finest hour from the foundry. I'm sure the reject bar was pretty low when your hours from going out of business.
I can understand the low buck scrounged up part allure, I have 2 such mutants here. One runs like a scalded gorilla, the other is a wet sponge. Both are mid 8:1 run on junk gas, use no oil and return reasonable mileage. I'm still sticking to my 275 number unless you change heads then I will agreed with your 325 number. Use the 202 valved heads you need all the help you can get. Let's hope they can get you to 300 and 100 mph trap speed in the 1/4

Yea I am aware of the 308 head. My understanding was the chamber was not as good as the 302. Guys with the FMJ Era 318’s like the 302 because of the heart shape swirl chamber & the compression increase. However the 302 is crack prone from what I read. They don’t seem to like the 308 head. I’ve never worked with either. Just reading the forums. I sure hope you are wrong on your HP estimate. I pulled up CME engines. Their 360 performance upgrade is 340 HP with 1.88 360 heads, 8.7 compression & loopy cam. Also pulled up the 71 360 specs. 2 bbl only in 71 and only offered in C bodies & pick ups. The gross ratting was 255 HP. In 72 a 4bbl was avaliable with a net ratting of 220. (Gross maybe 265) I agree the 360 head ain’t much to brag about but I think with the valve size increase & some pocket porting it will Wake it up a bit. Also I’ll be running headers & a slightly better than stock Eddy intake. Good cam & a windage tray. I just won’t have a lot of compression which I’m good with on this build. By the way I pulled up an article Hot Rod did on a 5.9 Magnum “budget buster build” . They got 420 Dyno HP & all they did was a .520 lift cam swap & a set of Eddy heads. That’s a lot of coin, but I guess that’s a lot of juice for the dollar hence budget.

 

[70bigblockdodge]

I think with the valve size increase & some pocket porting it will Wake it up a bit

I hope I'm wrong also, this will be where you pick up all you can get out of those heads. I would match the intake ports and push the pushrod pinch open some, those heads are really messy in there like small block chevy. Good luck and I'm watching and rooting for you.

 

[C Body Bob]

I hope I'm wrong also, this will be where you pick up all you can get out of those heads. I would match the intake ports and push the pushrod pinch open some, those heads are really messy in there like small block chevy. Good luck and I'm watching and rooting for you.

Yep I’ll talk with the machinist. See what he can do without getting too deep in my wallet. What went wrong with that one 360 you have that you said was a wet sponge.

 

[70bigblockdodge]

Yep I’ll talk with the machinist. See what he can do without getting too deep in my wallet. What went wrong with that one 360 you have that you said was a wet sponge.

It's actually a 400. Stock way down in the hole piston, compression is revived from the dead by a set of 516 closed chamber heads that enlarged to 1.74 exhaust valve. I cleaned up the ports, profiled the guides, matched the intake like I normally do. Headers, Wiend intake, same old Holley I've ran for years, and a 284/484 Mopar cam. It needs more compression or less cam, the drivability is crap. I had a bigger converter in it, made it run great and traction became a problem, it also sucked at 3800 on the road every where I went. All in all it needs a $5-600 converter more $ than I even have in the whole engine, or swap a $250 cam and lifters to bring it down to match the intake and compression. So probably late next spring I will bite the bullet and swap the cam. I have a couple other things that need addressed so I will just drop the engine and trans out to swap and fix needed stuff.

 

[C Body Bob]

Do you think a 2 degree retard on the cam would help it

 

[Mr C]

Enjoy the Dippy! Here's my winter beater after I finished the pre winter repairs...got it for $200.00.