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i need opions on my build.
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Author:  OleSkoolTony [ Sat Nov 09, 2013 6:31 pm ]
Post subject:  i need opions on my build.
hello folks!

im building my first engine, for the first classic ive ever owned. a 1965 valiant 100. id like to get as close to 300hp /6 powered as i can, although id be jazzed if i hit 250. im starting with 68-72 block n head. all i plan on keeping is the connecting rods and crank. im boring the block 40 over, i have a supersix 2brrl alum intake, holly 2bbrl carb, petronix replaceing the points, and a petronix coil. also got a new cam adv.d. 264 .50 220 l.s 110 440. im looking for advise for what to do with my head, and exhuast? i want the highest copression the slant will live with on pumpgas. also anyguess where my hp numbers could end up? i wanna use the 3speed and rear end from the factory. where do i sorce a yolk for her to rid the car of the ball n truin crap?

thanks. cheers!
Author:  olafla [ Sat Nov 09, 2013 11:49 pm ]
Post subject: 
Hi OleSkoolTony.
I think your best starting point would perhaps be the notes and tips in the Engine Build Matrix thread in the Frequently Asked Questions (FAQ) in the Engine section. For tips on the build itself, take a look at Best of Doctor Dodge.

Olaf
Author:  DusterIdiot [ Sun Nov 10, 2013 8:58 am ]
Post subject:  It'll be short...
Without a turbo the slant in the 250-300 range will not be a streetable engine. The cam you have listed will get you to the 160 range with that intake, the cam's characteristics will limit your SCR to about 9.5:1 before you need to run more than 92 octane ...I have been at the low 200 range on the Erson 280/270 and 10:1 compression, I'm closer to 225 on my race only engine (12:1 compression, large carb, headers, etc...It'll need a 4 barrel). You will need a heavy duty rear or the 7 1/4" with a sure grip at these levels.

The head is the key to getting more improvements, and recurving the distributor also provides gains on an improved engine.

Good Luck,

-D.Idiot
Author:  OleSkoolTony [ Sun Nov 10, 2013 11:07 pm ]
Post subject: 
omg. what? ya sayin ill gain 20hp after the build? fml. i dont get 500k. ill never forgive myself. bitch bettet produce 300 lbft of grip n rip.
Author:  slantzilla [ Mon Nov 11, 2013 2:35 am ]
Post subject: 
How do expect a tiny little engine to produce high performance numbers when you are putting nothing but stock parts in it?

Please put down the crack pipe.
Author:  OleSkoolTony [ Mon Nov 11, 2013 2:44 pm ]
Post subject: 
thanks for taking the time to be insulting and unhelpful slantzila. stock and tiny you say? 3.7 may not be massive, but it aint tiny. not to mention the cam, 40 over pistons, intake, and carb, are all not stock parts i have. im also thinking about decking the head, oversized valves, and a 5 angle. still uncertain about the exhuast. the purpose of this post was to get helpful replys and ideas on the head, and exhuast. also educated guess's to what hp numbers this engine may make. stock 225's of my engines era made 145. i didnt think making a 1hp per cube was too much to ask. not like im shooting for 100h p per liter. basically, slantzilla, if ya aint gonna be helpful, then please ... &#@% off. :0) cheers!
Author:  Ssg Pohlman [ Mon Nov 11, 2013 2:50 pm ]
Post subject: 
If you read more than you have typed on this forum then you would know what the slant is capable of already.

Advice was given by a couple of the most knowledgable guys we have on this site, if you don't want to take the advice then by all means cut your own path through the woods. It's your money burn it as you wish.

There is a search function at the top that will yield faster more indepth answers. Spend a good 12 hrs researching and reading already started topics, if it hasn't been answered by then, by all means come back and post what is missing.
Author:  OleSkoolTony [ Mon Nov 11, 2013 3:43 pm ]
Post subject: 
ok ive posted 3 times on this forum since ive been a member, though i visit the site atleast daily via cellphone. so i read much more then i post. the first few replys to my post were helpful. so lets stop with the rude comments, and keep it to engine talk here. if you are off topic, or being unhelpful, please, spare me.
Author:  OleSkoolTony [ Mon Nov 11, 2013 3:51 pm ]
Post subject: 
ssg, thanks. hey dutras are hands down the best way to go as far as it seems? the research ive done and info i get on this site, often leaves me more confused. lots of opion, im still trying to sort through whats fact, and whats opinion. all are welcome, and was just trying to make things easier.
Author:  Reed [ Mon Nov 11, 2013 4:04 pm ]
Post subject:  Re: i need opions on my build.
Quote:
id like to get as close to 300hp /6 powered as i can, although id be jazzed if i hit 250.
im starting with:
68-72 block n head;
i plan on keeping is the connecting rods and crank [stock];
im boring the block 40 over;
i have a supersix 2brrl alum intake;
holly 2bbrl carb;
petronix replaceing the points, and a petronix coil;
cam adv.d. 264 .50 220 l.s 110 440.

im looking for advise for what to do with my head, and exhuast? i want the highest copression the slant will live with on pumpgas.
Compression- calculate your target dynamic compression ratio and mill the head and block accordingly. There is no one size fits all answer due to casting variations across the years and differences in things like piston dimensions and cam profiles.

What RPM range are you going to operate your slant at?

What model two barrel Holley carb are you using?

Ditch the Pertronix and go to HEI with an E-core coil. If you are trying to make 300 RPM you are going to need al the help you can get. You are going to need to custom curve your timing advance curve.

Unless you are lucky and got a car with the somewhat rare 8 3/4 rear axle, the stock rear axle will not last behind a power slant. You most likely will not like the stock 3 speed transmission, either. And if you are going hog wild on the motor don't forget to upgrade your brakes and tires.

Be aware that the crank register changed sizes in 68. Verify that the transmission you want to use will properly mate to the 68 up crank.

Some people love headers, other prefer Dutras. Do your research and see the pros and cons of each, then make your choice.

Also, stock 65 slants might have been rated at 145, but that rating changed in 72. The 72 and later horsepower ratings are lower but more realistic. Do the research to see what each horsepower rating was actually measuring and why the 72-up rating is more realistic.

A stock slant six puts out 90-110 HP by todays standards and while it's displacement is large by todays standards it is nowhere near as efficient and powerful as today's motors of similar size. The cylinder head and valve train is the major limiting factor to the slant six and getting 300 or 250 HP out of the engine requires a very expensive build and almost certainly requires at least nitrous, if not some form of forced induction. A naturally aspirated slant six with that mild of a cam and operated at normal street RPMs will not make 250 HP.

Finally, you would be well served on this board and in life to be more respectful to other people, especially when they try and help you. Learning how to spell and how to communicate with proper grammar wouldn't hurt, either.
Author:  OleSkoolTony [ Mon Nov 11, 2013 5:06 pm ]
Post subject: 
thanks.
i forget the carb model info. ill get ya that info.
i also have the flywheel for the 68 engine.

cool so 160 would be a 60-70 hp increase. that makes much more sense. im sure it gonna feel like a beast compared to the stock worn out 170 the car came with.

i have plenty of respect for people, untill i have reason not to. my engine isnt getting all stock parts, i also dont smoke crack, also dont have a crackpipe. how is "put down the crackpipe" helpful my friend? i have no respect for people who go around treating people who ask questions like they are stupid. slantzilla wasnt trying to help. he was being an @$$#&!% because its easy to do on the net.

as far as grammer and spelling? well,its hard on a crappy touchscreen cellphone, im also terrible with spelling. i use more punctuation then most on the web, and i feel i communicate my thoughts well. mistakes happen. just like the one where yoy said 300rpm.
Author:  DusterIdiot [ Mon Nov 11, 2013 7:48 pm ]
Post subject:  I have...
Quote:
Compression- calculate your target dynamic compression ratio and mill the head and block accordingly. There is no one size fits all answer due to casting variations across the years and differences in things like piston dimensions and cam profiles.

What RPM range are you going to operate your slant at?

What model two barrel Holley carb are you using?
Since I have run over bores like his on race and street engines, I am most familiar with how these work.

Just as an FYI, over boring doesn't get that much more displacement unlike the modern/V-8 engines (a .060 overbore is a whopping 232 CID..so no real gains there unless you are overboring to unshroud the oversized valves).

The 1965 head can go, the dime spot chamber is prone to pinging unless you grind that out or just go with a 1967-1974 head with the revised chamber. 80% of the slants breathing difficulty in in porting the head and bowl work...just making some subtle changes in a stock engine here can help the 1 barrel car move along.

The point Slantzilla was trying to make was that the 2 barrel intake will be your next issue/ pinchpoint on flow for power (I guestimated the 160 mark as that was what my 1967 Signet made with a comp CCX256 cam factory 3spd manual, 2.94 rear (luckily the 7 1/4 didn't get more than 5-6 hard lauches before I swapped for an 8 1/4 sure grip).

I ran the numbers on your "build" through the DCR calculator and the desktop dyno I use with actual flow numbers and cam grinds...the 264 is tame for the 1CID=1HP even at the crank....

Given these assumptions:

Super six intake
Holley 0-7448 350 cfm 2 barrel (the 500 cfm is cranky and doesn't stay tuned long and isn't happy with the small ports of the BBD intake).
Minor gasket matching.
Comp 264 installed at 4 degrees advanced for best torque/street driving
i.e. 106 intake centerline, typical grind at 264/264 110 LSA and .440 lift

Say block prep as:
.040 overbore
Block decked for a .080 deck height
Head prepped for 54 cc w/1.70 & 1.44 valves
Comp head gasket at .039 crush and 3.5" bores
SCR = 9.68
DCR =8.12 (which means you may run it on higher octane pump gas/super if your timing/carb is correct)
Assume you run headers and duals at 2" with good flowing mufflers

Dyno estimate=maybe 180 at 5000rpm (a lot less at street rpms...typically take 10-20 hp off the "computer dream" results for real world values), and 230 ft/lbs at 3500

The bad part is you can't advance that cam too much more to make real gains, and if you bump the compression up, the 110 LSA will cause higher cylinder pressure and...cause the DCR to rise quickly (so you need 100 octane if you just change the chamber in the above number crunch to 50...which is not that much of a cut off a late head that starts at 54 cc, or a machinist "whoops")...

To run you through a scenario based on my "lou" build...and why you do the homework before buying the stuff:

Given these assumptions:

Hyperpak intake/ or even a clifford shorty.
Holley 0-8007 390 cfm 4 barrel (swap to 600 cfm for races at the track for another .5 second drop in time).
Head Porting and bowl blending.
Erson 280/270 installed at 4 degrees advanced for best torque/street driving(i.e. 107 intake centerline, typical grind at 280/270 111 LSA and .470 lift)

Say block prep as:
.040 overbore
Block decked for a .089deck height
Head prepped for 50 cc w/1.70 & 1.44 valves
Comp head gasket at .039 crush and 3.5" bores
SCR = 10.01
DCR =8.10 (which means you may run it on higher octane pump gas/super if your timing/carb is correct...but I have found I can run it on 87 crap gas with 4 degrees of timing yarded out of it while going to work)
Assume you run dutra duals and dual pipes at 2" with good flowing mufflers (note these mufflers will drone at 2200 rpm in this setup...with an earlier body you may not get the dutras to be a true dual until under the car....)

Dyno estimate=maybe 205 at 5000rpm (a lot less at street rpms...), and 250 ft/lbs at 3500...actual reverse engineering from 1/4 mile time with the Holley 390 on it is about 187-196 HP (having a manual tranny with 3rd locked up helps too, but is murder on clutches)

What's the difference?

In realm #1, the smaller cam would work fine in the mid 9's compression but builds cylinder pressure faster and retains it due to the shorter over lap event, thus not allowing you to go beyond this level of a build...

In realm #2, the larger cam allows you to use much more compression, allowing for a longer overlap to bleed down cylinder pressure to put the engine back into the goal posts of working on the street, but...also allows you to make larger gains if you use headers, swap to a little bigger carb at the track, and if you over shoot your compression ratio (say a few for cc since the machinist didn't CC it correctly or he didn't know that .0066"=1cc on the scrape...it's more 'friendly' up to a point-don't try for 11:1 SCR that'll be race land again.).

So that becomes your research and choices on the road you will and won't take....make sure to book mark some engine math sites and a DCR calculator...I will also back up Reed on going EI, the points distributor even with the conversion is not the best for recurving, if you can get a super six dizzy it will allow more initial and less mechanical advance for performance driving and power curving.

If it's a race only car, a Jeffrey head and running top end compression will have no problems netting 250hp at the rear wheels.

I'll get off my Sun Distributor Machine box now...

-D.Idiot
Author:  slantzilla [ Mon Nov 11, 2013 9:54 pm ]
Post subject: 
No, you want to build a high performance engine with stock parts. Nothing you listed is much of an improvement over a stock motor, yet you want 250-300 horse.

The difference is I have such an engine as you want. It contains nothing you want to use.

You want to make horsepower with a tiny motor you need a clue, a plan, and a realistic idea of what you are doing. There is a huge difference between doing it with a late injected motor in a fairly light car and an outdated economy motor in a heavy car.

Yes, my comment was a little short, but it gets old seeing guys like you come on here thinking you can throw some stock shyt at a Slant and triple the factory horsepower. It just don't work that way.
Author:  Rick Covalt [ Tue Nov 12, 2013 6:25 am ]
Post subject: 
Just as a matter of truth. If you do a nice build and you get to 180-200 HP it will feel like a rocket compared to what you have stock.

If you are building for performance then dump the 2 barrel altogether and get 500 Edelbrock on a 4 barrel manifold. The rear will need to go and lower gears will make it feel all the faster.

As anyone on here will tell you, it all has to work together. The right combination of parts for what you want to do. Then the transmission to work with the engine, (shift kit...etc) and the proper rear end ratio that will compliment what your trying to do.

Look at some other peoples builds and pick the one that best suits your goals.
Rick
Author:  1974duster kev [ Tue Nov 12, 2013 11:09 am ]
Post subject: 
Welcome to the board!

Not to throw any fuel on this subject but the first NA motor I built for the duster seemed to make somewhere in the neighborhood of what your after?
9.6 @ 74mph in the 1/8 mile vs my stock time 12.1@61mph lol
The NA motor was my attempt to make power and keep it simple since it was my first engine build.
Cam: erson 238@.050 510lift on a 108 lsa
Compression: 10:1 cast 40over pistons factory forged rods/crank
Head: lots of hours bowl blending porting and the .100+ cut for compression and oversized valves 3 angle valve job
Intake: 4bbl Clifford with a 390holley 4bbl carb
Exhaust: Clifford shorty headers with dual exhaust all the way out back
read end: ran the 7 1/4 plenty of passes never broke it gave it to charrlie when I put my 8 3/4 with 3.73 gears in because I knew I wanted more power adventually.
This engine was never dynoed but just judging I would be some gt mustangs at the track should have been around 250hp maybe better who knows.
So all in all that old NA motor had more cam and carb than what you described above and the full body street trim duster seemed to run pretty well but some of my gains probably came from the amount of time and work I put into the head. Just my opinion if you stepped your cam choice up a lot would allow more timing and power on pump gas to bleed off some dynamic compression plus slap a 4bbl on it :)
Shoot I still have that motor and carb sitting on an engine stand :)

P.S. I forgot to mention it had a 3000rpm converter in the 904 auto then went to a 4speed setup but ran similar times just was easier to get a better launch when it had the auto.

Kev
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