First of all I have gotten a great deal of info that will take me a long time to absorb. I like all of the differing views because it makes me think and research more. Learning it and then doing it is a large part of why I picked this hobby.
A lot of the info went right over my head but I'm learning.
About the stickers, remember I am trying to build a mild street machine not a race car. Too many stickers, too much HP, can't get it all to the ground.
About the stickers, remember I am trying to build a mild street machine not a race car. Too many stickers, too much HP, can't get it all to the ground.
Aw, shucks, that's easy.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
As stated it's not perfect but it's close enough. To add 50 hp to the 350 hp 8:1 example, change the CR to 13:1. A one point increase yields about 4% more power give or take and usually about double that in fuel economy. But there just isn't as much hp in compression as most people think.
The half point gained by doing the $300 worth of machining would give about 6 hp, costing $50 per hp. If you start off with better heads and the end cost is the same it's now free hp.
If you can do this several times during the build by selecting the right parts you can make 20-30 hp more on a mild build than someone who just rebuilds what they have. This is how I make my living, making more power than other engine builders for the same or less money - and proving it on the dyno and at the track.
I agree, publishing proven packages helps a lot! I think there was a thread on that once but if not a new one would be a good idea! I'lll dig up the dyno results for the ones I've tested.
To cover the 50 hp (or more) for a couple hundred bucks - how about the real thing instead of stickers. As in a real NOS setup.
To give the original poster an idea of where one can go with his original question, I have a 455 engine under construction at a machine shop. All I provided was the block, connecting rods and the unique to '67 attachments such as the timing cover and water pump along with the other periferals such as the fuel pump, carb core (for rebuilding), distributor, and other small stuff.
I told the builder to construct the engine the way he would if it was his car. We are going aluminum heads, roller camshaft, forged pistons.
The builder is estimating we will get about 500 hp out of it for a cost of about $6,500. I also asked him to break it in on his dyno and will therefore find out for sure how much HP it will have (no bench racing!)
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement 2006 Mustang V6 Pony, Vista Blue. Factory ordered. 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it. 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI
That should be pretty close, one of the 400s I did made right around 450 hp on the dyno with the Edelbrock heads and the RA IV cam. That was up about 45 hp from a previous 400 with ported #48 heads and a slightly milder Crower cam.
But there just isn't as much hp in compression as most people think.
The half point gained by doing the $300 worth of machining would give about 6 hp, costing $50 per hp. If you start off with better heads and the end cost is the same it's now free hp.
If you can do this several times during the build by selecting the right parts you can make 20-30 hp more on a mild build than someone who just rebuilds what they have. This is how I make my living, making more power than other engine builders for the same or less money
All the above is very true. I based what I wrote, the decking and milling (extra work but fairly common and will raise compression a few 10ths, which at this low level should be a big help for combustion efficiency) on the assumption that the cam will get changed (why would you use the original) Maybe change the intake and carb (easy and more modern available) Ignition (again, more modern) and upgrade the Exhaust (why wouldn't you)
All those parts are fairly standard changes done on a rebuild/upgrade and cause no reliability issues and yeild a decent HP increase over a stock low compression smog era mtr. Personally, if I was going to build this 455 I'd change heads, cores are cheap, compression can be raised easily, no ill effects by getting in the low 9's, and open up the intake and exhaust to let the engine breath, a 455 is a very big air pump. No way would I spend the money to rebuild that 455 as stock and put it in a FGF, seems a waste of time and money, for a little more it would be 10 fold better in performance and value.
Guess I'm over my 2 cents now.
Wanting a Custom fit in an off the rack world.
I don't have time for a job, I just need the money.
Yep, I was pretty happy with that price including the carb rebuild and the dyno break-in - especially after reviewing Butler's and Pontiac Greg's (Colorado) web sites for their prices with a core.
It's actually going to be $6,800 out the door with a custom torque converter from the tranny shop next door (the owner used to race a '68 Ram Air II and a GTO)
I can't wait to get this beasty back on the road!!!
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement 2006 Mustang V6 Pony, Vista Blue. Factory ordered. 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it. 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI
It will be interesting to hear what Eldon has to say after he gets back from the builder and machine shop. He's checking out what it will cost to follow our advice with using the original heads. I gave him the advice to get an Edelbrock Peformance package to keep all the parts compatible. He will end up with close to the same build I had for my 428. The difference is he will have a zero deck. The 428 ran perfect for a fun dependable driver. I wouldn't have changed a thing. It's still a great cruiser 10 years after I built it. Amazingly using 89 octane gas!
"When asked for his thoughts on the thermal efficiency differences between cast-iron and aluminum, and its effects on performance, Bisschop replied, "There's no doubt that aluminum is less efficient than cast-iron. We've found, with all variables being equal, that an aluminum head needs roughly 3/4 of a point more compression to generate the same power as a cast-iron head. We regularly shoot for a compression ratio of 9.5:1 with iron heads and 10.25:1 with aluminum heads on our pump gas engines.""
I guess I was conservative at half a point of compression needed for the aluminum heads to match iron heads. The reason that E-heads pick up extra power is mostly the port flow and some from the chamber design, not the material.
The Edelbrock Performer cam is a direct copy of the RA IV cam. Cheaper RA IV cams are out there from Melling, Summit, and others if you want to put together a package of your own.
"When asked for his thoughts on the thermal efficiency differences between cast-iron and aluminum, and its effects on performance, Bisschop replied, "There's no doubt that aluminum is less efficient than cast-iron. We've found, with all variables being equal, that an aluminum head needs roughly 3/4 of a point more compression to generate the same power as a cast-iron head. We regularly shoot for a compression ratio of 9.5:1 with iron heads and 10.25:1 with aluminum heads on our pump gas engines.""
I guess I was conservative at half a point of compression needed for the aluminum heads to match iron heads.
The Edelbrock Performer cam is a direct copy of the RA IV cam. Cheaper RA IV cams are out there from Melling, Summit, and others if you want to put together a package of your own.
The foolproof thing about using the Edelbrock packages is that you can talk with them on the phone. You tell them exactly what you have, weight, gears, displacement, compression, transmission, ideals for driving. They get you the perfect package. I can attest from personal experience that it's a great way to go. No guess work at all. No trial and error... Sometimes experimenting is fun. If you want it right the first time 'round, they nail it for you.
The foolproof thing applies to any KNOWLEDEGABLE Pontiac builder regarding exactly the same things above.
Any reputable builder, Pontiac or not will always ask those same questions when building a motor. It does not only apply to Edelbrock, as inferred.
When you have a reputable and experienced Pontiac engine builder build anyone a motor, there is as well "no guess work" or "trial and error" either.
This lack of common knowledge applies if the respondant has never been to a machinist to have a motor built. Likewise, the "trial and error" and "no guess work" is nullified if I do all the machining for Eldon, and he installs whatever cam, heads, carb, rocker ratios, intake etc.
If a Pontiac machinist (Butler, Nunzi, Bischop, Pacific, Kauffman, Spotts, Keefer, Old Man Taylor) builds a motor, you can be sure it will be done to the owners request and specifications.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
The foolproof thing applies to any KNOWLEDGABLE Pontiac builder regarding exactly the same things above.
Any reputable builder, Pontiac or not will always ask those same questions when building a motor. It does not only apply to Edelbrock, as inferred.
When you have a reputable and experienced Pontiac engine builder build anyone a motor, there is as well "no guess work" or "trial and error" either.
This lack of common knowledge applies if the respondant has never been to a machinist to have a motor built. Likewise, the "trial and error" and "no guess work" is nullified if I do all the machining for Eldon, and he installs whatever cam, heads, carb, rocker ratios, intake etc.
If a Pontiac machinist build it, you can be sure it will be done to the owners request and specifications.
Tom Tom Tom.. Sadly still attacking my posts instead of the subject. I'm flattered(not) by the constant attention but I'm sure your expertise could be used for more constructive purposes. And you have a great day sir!
I am not attacking your posts..again, attacking the fact that your math and pseudo engine bench building is totally and factually incorrect. I hope these people realize by now that this farce of your incorrect information will cost them in the future.
Again, not attacking you, just the really irrelevant and out of touch opinions (as incorrect as they are) regarding machining which I and (we) still have not recieved an answer to those questions. Must be because you can't answer them and Brent even showed by the use of the calculator that your .025 and .025 will not do anything relevant.
But of course you prefer to skirt the matter when you are wrong as most of your machining principles are.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
Edelbrock does not offer a "perfect" package. There is no such thing. Every build is a compromise. An all out race build compromises streetability. A maximum economy build compromises performance. Edelbrock goes down the middle and packages parts that will give a reasonable balance, but what you get for the price is not "a bargain".
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
Edelbrock does not offer a "perfect" package. There is no such thing. Every build is a compromise. An all out race build compromises streetability. A maximum economy build compromises performance. Edelbrock goes down the middle and packages parts that will give a reasonable balance, but what you get for the price is not "a bargain".
Take a read back a few and you will see what the procedure is with Edelbrock. I've done it myself with great 'documented' results. Maybe you would like to see the video?
Still a compromise, and even more so because you don't have the freedom if building "all Edelbrock" to choose the parts BEST suited, you choose from what they sell. Sure, it's easier, and the results can be good, but I can do better by putting it in the hands of my favorite shop and giving the same parameters as an Edelbrock order form. And I spend less for it, and get a local warranty and post-build support.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
I have decided to look for heads local first but if I can't find them close to me I will be contacting a couple of you to get some.
My question now is, I have the other 78 400 short block that I was going to build and was wondering if the old 4x heads will go on this engine for someone that is not looking for anything special. Do the cc's work out on heads from a 73 455 on a 78 400. The 400 shortblock is already rebuilt and maybe someone can use it. Thanks Eldon
I have decided to look for heads local first but if I can't find them close to me I will be contacting a couple of you to get some.
My question now is, I have the other 78 400 short block that I was going to build and was wondering if the old 4x heads will go on this engine for someone that is not looking for anything special. Do the cc's work out on heads from a 73 455 on a 78 400. The 400 shortblock is already rebuilt and maybe someone can use it. Thanks Eldon
Read his whole post. Speedreading are we? He's willing to pass the 400 on... I can't hold a straight face so I'm gone from this one....
I am asking about the 400 because I have the shortblock rebuilt already.
For me I am building the 455.
I will be trying to get rid of the 78 400 shortblock.
I am building the 455 w/ better heads and a mild cam 280 or so and a stock intake, not sure of the carb jet. Headers and nice exhaust system will be part of the project also.
I am only asking about the 400 to find a way to get rid of it. Thanks Eldon
My question now is, I have the other 78 400 short block that I was going to build and was wondering if the old 4x heads will go on this engine for someone that is not looking for anything special. Do the cc's work out on heads from a 73 455 on a 78 400. The 400 shortblock is already rebuilt and maybe someone can use it. Thanks Eldon
The sad thing is that Geoff and the mods have a low tolerance for your idiocy and baiting. That is why you hide behind a keyboard and throw out crap that makes absolutely no sense, rhyme or reason.
The numbers were thrown out there because in order for a 400 to run decent, the cc difference between a 4X 114 cc head and the correct 78-85 cc head is about 30 cc.
Jim, get a life. You know NOTHING about building a Pontiac and it is clear and obvious that you don't.
Oh, thats right! You have desktop dyno 2008!
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
In order for him to sell the 400 with decency and integrity and to not screw someone over, he needs a head in the 78-85 cc range. And his question is answered.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
I don't want to screw anybody so now I may be looking for heads for both my engines. It seems I am the one who got screwed with the first 400 shortblock. That is most likely why he was selling it. What heads (number would help instead of cc) am I looking for for the 400.
Use one of the compression calculators to see what a promising head would give you for compression. Aim for 9-9.5:1 for premium pump gas depending on the cam (more duration allows/needs more compression). This is conservative and leaves a good safety margin for tuning, mediocre gas, non-zero deck, somewhat warm engine temps, things like that.
In order for him to sell the 400 with decency and integrity and to not screw someone over, he needs a head in the 78-85 cc range. And his question is answered.
why only that low? mine are 88cc and runs great on my 400....wouldnt 82-90 be better for "street" and pumpgas, like regular? just curious...it just seems low with 78 to me...but again I am NOT an engine builder , just a bystander...
10 cc's is roughly .75 points of compression on a 400. Figure if 80 gets you in the low 9's (depending on deck ht and other things) 90 gets you mid 8's. It's all related to bore and stroke. Even though the bore isn't that much different between 400's and 455's the stroke changes everything since it's a compression ratio. Ratio is volumn filled to volumn sqeezed. I think I said that right.
Wanting a Custom fit in an off the rack world.
I don't have time for a job, I just need the money.
why only that low? mine are 88cc and runs great on my 400....wouldnt 82-90 be better for "street" and pumpgas, like regular? just curious...it just seems low with 78 to me...but again I am NOT an engine builder , just a bystander...
Bjorn..Your 88 cc 5C heads were either 98 cc or very rare 91 cc 350 AIR heads (for comparison) The 400 would run, but run real poor with 98 cc 5C's and still not that great with 91 cc 5C heads. I had a 400 in my 67 that had 5C 90 cc heads in them. I thought it ran great as well until I rebuilt a set of small valve 80 cc 46's. You would think that smaller valve would be a dog, but I raised the compression and reduced the valve size, yet not the "ideal" setup. I just bolted them on in an afternoon and took my 5C's to the shop.
He could go with 5C's but they are hard to find in the smaller chambers. I said that range because I do not think Eldon wants to buy a set of heads and spend machining money in order to sell the 400.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
Another thing about heads..Yes, the chamber size in finite unless you want to mill. There are ways to manipulate actual compression with cam duration, deck, piston cc's, carb tuning, timing etc. Some of this applies to both high and low compression engines but most of this benefits over 9.5 to 1 and higher.
Person A can have 10.2 to 1 compression and run a large high duration/overlap cam and not detonate whereas person B with 10.2 to 1 has issues with a different cam, leaner carb..etc.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
why only that low? mine are 88cc and runs great on my 400....wouldnt 82-90 be better for "street" and pumpgas, like regular? just curious...it just seems low with 78 to me...but again I am NOT an engine builder , just a bystander...
Bjorn..Your 88 cc 5C heads were either 98 cc or very rare 91 cc 350 AIR heads (for comparison) The 400 would run, but run real poor with 98 cc 5C's and still not that great with 91 cc 5C heads. I had a 400 in my 67 that had 5C 90 cc heads in them. I thought it ran great as well until I rebuilt a set of small valve 80 cc 46's. You would think that smaller valve would be a dog, but I raised the compression and reduced the valve size, yet not the "ideal" setup. I just bolted them on in an afternoon and took my 5C's to the shop.
He could go with 5C's but they are hard to find in the smaller chambers. I said that range because I do not think Eldon wants to buy a set of heads and spend machining money in order to sell the 400.
ok, 98 sounds right...I think we cc checked`d them to 97-98, so I didnt mess up any rare heads..
Edelbrock does not offer a "perfect" package. There is no such thing. Every build is a compromise. An all out race build compromises streetability. A maximum economy build compromises performance. Edelbrock goes down the middle and packages parts that will give a reasonable balance, but what you get for the price is not "a bargain".
Maybe not the best build or bargin, but a 375-400 HP bolt on package with 14-16 mpg = not bad.
