LA 318 advice

[Baggs]

Oops, I meant “shorty header style CI exhaust manifolds”.
Mine don’t go straight down, but have maybe 12-14 inches of length to them

 

[66fs]

... I’ll die grind on the heads like I’ve done in the past (remind me to stay away from the seats please) and put it together when the shop does what I ask, just a square deck at 9.58 and be back in business.

I pretty sure have spare valves you can use to protect your seats. I usually have a few used ones in my stash. Exhaust valve stems are usually worn so it best to replace them anyway. Sounds like you know how to measure them. Just let me know.

 

[318willrun]

I did a intake test on a very mild 318. Factory '73 340 cast, Weiand Action Plus, Holley Street Dominator. All ran within 1 mph and 1.5 tenths of each other. The factory cast had the best mph & ET, even though it had the largest port mis-match to the 318 heads. 2nd was the Action Plus, even though lighter it ran 1 tenth behind the cast. Oddly enough, the Holley SD being a single plane actually gave the best 60 ft (barely), but the worst overall ET by 1.5 tenth and MPH was barely a click behind the others.

Bottom line is they all performed very close. Folks worrying about the mis-matched ports on a mild 318 are repeating what others posted or some other online gibberish without personally trying it.

 

[66fs]

... Folks worrying about the mis-matched ports on a mild 318 are repeating what others posted or some other online gibberish without personally trying it.

A lot of that going on, and not just intakes.

 

[318willrun]

I did a intake test on a very mild 318. Factory '73 340 cast, Weiand Action Plus, Holley Street Dominator. All ran within 1 mph and 1.5 tenths of each other. The factory cast had the best mph & ET, even though it had the largest port mis-match to the 318 heads. 2nd was the Action Plus, even though lighter it ran 1 tenth behind the cast. Oddly enough, the Holley SD being a single plane actually gave the best 60 ft (barely), but the worst overall ET by 1.5 tenth and MPH was barely a click behind the others.

Bottom line is they all performed very close. Folks worrying about the mis-matched ports on a mild 318 are repeating what others posted or some other online gibberish without personally trying it.

THE HEADS.... and I'm not going to read through 8 pages of what's being argued here, so I don't know if this has been discussed. But we putting 340/360 heads cut .040 on a 318 has EVERY TIME made the car go faster. No, we didn't cut the intake too, never had to. IN fact, it fit better (bolt holes lined up better) after the heads were cut .040. In all truth, one of the common street mods that used to happen to 318's was slapping 340 heads/intake/and carb on it.

 

[66fs]

.040 off 340/360 should give a little less than 65cc chambers. I always cut the intake side of head .038 just because I know that is what the Racing Manual says. Never had a problem either or port mismatch.

 

[318willrun]

I'll also say the fastest way to kill a stockish 318 with stock converter and highway gears is to over cam it. Like a MP 292 LOL

 

[318willrun]

We put a used 340 cam, with worn 360 heads (valve guides were shot, but cut .045) and a cast intake and TQ on a 318. STock 727 and converter, 3.21's. It was a "no budget" build... LOL. Cast intake and carb was 10 bucks, free cam, 30 dollar heads and paid to cut them, did the valves ourselves hand lapping and a flashlight. Ran 14.40 at 96 mph. No, not a land rocket, but enough to run with any stock 340 car and faster than a ton of "muscle cars" from the era.

 

[273]

I did a intake test on a very mild 318. Factory '73 340 cast, Weiand Action Plus, Holley Street Dominator. All ran within 1 mph and 1.5 tenths of each other. The factory cast had the best mph & ET, even though it had the largest port mis-match to the 318 heads. 2nd was the Action Plus, even though lighter it ran 1 tenth behind the cast. Oddly enough, the Holley SD being a single plane actually gave the best 60 ft (barely), but the worst overall ET by 1.5 tenth and MPH was barely a click behind the others.

Bottom line is they all performed very close. Folks worrying about the mis-matched ports on a mild 318 are repeating what others posted or some other online gibberish without personally trying it.

Richard Holdener did an air gap vs 360 4bbl on a mild 360, it had decent gain's mainly in the middle of the powerband, the top and bottom was very similar power wise. Start's around 8.20



Engine masters dis dual plane M1 vs Airgap pick up 20 hp on a mild magnum, guessing making the M1 similar to stock intake too.

 

[318willrun]

Richard Holdener did an air gap vs 360 4bbl on a mild 360, it had decent gain's mainly in the middle of the powerband, the top and bottom was very similar power wise. Start's around 8.20



Engine masters dis dual plane M1 vs Airgap pick up 20 hp on a mild magnum, guessing making the M1 similar to stock intake too.

I know that a dyno is a very valuable tool. Great info can be gathered. I know you quote/post richard a lot. I'm strange, I like boots on the ground. AKA - ET slips. I still say that at the end of the day, the response is different from Dyno vs Track. Not saying he is wrong with his results, of course. Andy Wood did a great video on "the dyno is not the track". He found out after having mixed boss perfectly tuned on the dyno, it needed retuned at the track.

 

[toolmanmike]

Exactly! Dyno's produce a number. They measure torque and from that, calculate horsepower. It can be a valuable tool for tuning and comparing components. but, time slips will tell you what really works and how much, from a practical standpoint.

 

[273]

I know that a dyno is a very valuable tool. Great info can be gathered. I know you quote/post richard a lot. I'm strange, I like boots on the ground. AKA - ET slips. I still say that at the end of the day, the response is different from Dyno vs Track. Not saying he is wrong with his results, of course. Andy Wood did a great video on "the dyno is not the track". He found out after having mixed boss perfectly tuned on the dyno, it needed retuned at the track.

I didn't post this to contradict what you said, I felt it enhanced what you said, the airgap is held up pretty high as a performance piece I didn't think it did that well over factory especially since there was also a carb swap also at the same time.

I agree with ya but why I keep posting this and other vids, there's only few dyno results we have on stockish 318/360 with reasonable mild builds off generally low cr bottom ends, which is where a lot of people are at, so to me it's very valuable info for these people. This one don't have any track time but was his personal van engine so there's a little extra insight there, be nice if there was track time to back up these results, A member here bought the Magnum one I post, not sure if he plans on running down the strip.

You document you progress well so it also very helpful info. Wish more would do the same.

 

[273]

Hp tells your potential, track results tells you how much of that potential you're using.

 

[318willrun]

I didn't post this to contradict what you said, I felt it enhanced what you said, the airgap is held up pretty high as a performance piece I didn't think it did that well over factory especially since there was also a carb swap also at the same time.

I agree with ya but why I keep posting this and other vids, there's only few dyno results we have on stockish 318/360 with reasonable mild builds off generally low cr bottom ends, which is where a lot of people are at, so to me it's very valuable info for these people. This one don't have any track time but was his personal van engine so there's a little extra insight there, be nice if there was track time to back up these results, A member here bought the Magnum one I post, not sure if he plans on running down the strip.

You document you progress well so it also very helpful info. Wish more would do the same.

No, I got it. You posted it to support what I said. And essentially it did. And nothing against Richard at all, I'm glad he does his tests!

 

[toolmanmike]

I didn't post this to contradict what you said, I felt it enhanced what you said, the airgap is held up pretty high as a performance piece I didn't think it did that well over factory especially since there was also a carb swap also at the same time.

I agree with ya but why I keep posting this and other vids, there's only few dyno results we have on stockish 318/360 with reasonable mild builds off generally low cr bottom ends, which is where a lot of people are at, so to me it's very valuable info for these people. This one don't have any track time but was his personal van engine so there's a little extra insight there, be nice if there was track time to back up these results, A member here bought the Magnum one I post, not sure if he plans on running down the strip.

You document you progress well so it also very helpful info. Wish more would do the same.

Agree 100% with both of you. This "is" great info for the most of us that are looking to wake our Teen up without building a complete engine. Almost every thread about that goes towards "maximum horsepower" or a 360 swap. Nope, not what I want or the direction I want to go.

 

[toolmanmike]

Agree 100% with both of you. This "is" great info for the most of us that are looking to wake our Teen up without building a complete engine. Almost every thread about that goes towards "maximum horsepower" or a 360 swap. Nope, not what I want or the direction I want to go.

If I wanted to build a 408 I would have it done by now and I wouldn't waste my time asking for opinions as to how much difference an LD4B will make on my 70 318.

 

[318willrun]

Hp tells your potential, track results tells you how much of that potential you're using.

Agree 100% with both of you. This "is" great info for the most of us that are looking to wake our Teen up without building a complete engine. Almost every thread about that goes towards "maximum horsepower" or a 360 swap. Nope, not what I want or the direction I want to go.

First, the dyno is great for working with the engine on the stand for tuning and parts testing. But not so much as comparison as Dyno's vary. Second, the dyno brake cannot simulate all that goes into a car going down the track. Like wind resistance (as the car goes faster), change in gearing as the car shifts, and the workload changes. This is why we see dyno'd 400 hp motors go 12.8's in a 3200 lbs car without wheel spin. I can tell ya, it don't take anywhere near 400 hp to run that number.

 

[273]

Agree 100% with both of you. This "is" great info for the most of us that are looking to wake our Teen up without building a complete engine. Almost every thread about that goes towards "maximum horsepower" or a 360 swap. Nope, not what I want or the direction I want to go.

People can say to there blue in the face that a low cr 318 can be made into a performer, but show one dyno build and or track build like 318willrun's cut's through most of the nonsense for most, except the few that made it their mission in life to stop anyone from hopping up a 318

 

[66fs]

We put a used 340 cam, with worn 360 heads (valve guides were shot, but cut .045) and a cast intake and TQ on a 318. STock 727 and converter, 3.21's. It was a "no budget" build... LOL. Cast intake and carb was 10 bucks, free cam, 30 dollar heads and paid to cut them, did the valves ourselves hand lapping and a flashlight. Ran 14.40 at 96 mph. No, not a land rocket, but enough to run with any stock 340 car and faster than a ton of "muscle cars" from the era.

What! If you put all the good 340 parts on a 318, it'll run like 340? Who would of thought... Except those of us who actually did it.

 

[318willrun]

What! If you put all the good 340 parts on a 318, it'll run like 340? Who would of thought... Except those of us who actually did it.

Almost.. lol ... still giving up 22 cubes in bore is still substantial, but a good tuner with the 318 can make up a lot of the difference to many that just turn the key and think the 340 gives them the automatic win.

 

[66fs]

I have to laugh. Bench Racing or horse power numbers, never could stand either. Get off your duff, take them out and run them. All theoretical BS involved.

 

[fishmens67]

Exactly! Dyno's produce a number. They measure torque and from that, calculate horsepower. It can be a valuable tool for tuning and comparing components. but, time slips will tell you what really works and how much, from a practical standpoint.

PBR had the perfect rolling dyno.

 

[66fs]

Almost.. lol ... still giving up 22 cubes in bore is still substantial, but a good tuner with the 318 can make up a lot of the difference to many that just turn the key and think the 340 gives them the automatic win.

Yes, but how many 318 2 barrel owners could imagine what a 340 runs like. The difference is night and day. As far as numbers go I could tell stories of big cube, supposed high horse power cars that were so slow due to lack of tuning or mismatched combinations. And I'm not a drag racer.

 

[273]

What bugs me about this 318 vs X debates, is they over sale the negative aspects of the 318, if they were more honest about the differences and didn't over exaggerate positive's on one and under play the other, I would generally have little to say in these debates, they almost always act like 318 people want way too much from a 318 and it's gonna take a Nascar R&D team to accomplish it with a dump truck full of cash. It's ridiculous.

 

[Newbomb Turk]

I know that a dyno is a very valuable tool. Great info can be gathered. I know you quote/post richard a lot. I'm strange, I like boots on the ground. AKA - ET slips. I still say that at the end of the day, the response is different from Dyno vs Track. Not saying he is wrong with his results, of course. Andy Wood did a great video on "the dyno is not the track". He found out after having mixed boss perfectly tuned on the dyno, it needed retuned at the track.

You are speaking from inexperience.

You have zero clue how much power you make and where you make it.

Most guys easily leave 20-30 hp on the table.

The time slip is only the end all when the dyno numbers and the time slip agree.