Already planning next engine build

[barnett468]

I tried to buy the Blue Thunder Intake yesterday from dscmotorsport & they put me on a 5 week waiting list. I'm not in any real hurry, still winter here. Just thought I'd let you guys know.

That figures . . Their site says they are avail . . Try the site below.

http://www.survivalmotorsports.com/BlueThunderImages.html

 

[jpaz]

Ya, thank's I'll give them a try. Actually, they are located about an hour or so from me.

I really want to try this instead of the performer that I have on now. The port size difference looks huge. It should make quite a difference.

 

[barnett468]

Ok enough guys. This is turning into a pissing match and no help to the original poster, Omie01, me or anyone else. There are some very good points made, if one can follow them, but to me as a relatively new member, I am starting to wonder just who can I trust for the information I need. I have similar questions about my re-build, which is starting next week and have been favored with lots of useful tips in that regard from both of the "contestants" (and many others) about said build.

I joined 7173Mustangs.com because, as a relatively un-experienced owner of a 351C 4V, I had hoped for better things and the information I need. Clean it up guys and lets stick to relevant facts that us less knowledgeable members are seeking. Yes, I too have been guilty of getting 'off track' somewhat in my posts, it's all to easy to do as we're all enthusiastic and passionate about our hobby and that's OK to a point, but..................!

Geoff.

There is a polite way to have an intelligent discussion and then there a rude and offensive one . . Paul of MO has intentionally chosen the latter, and I for one will not not sit idly by when people make posts like he did . . It is disrespectful to everyone, and as I mentioned, if he or anyone else wants to act this way, there are many other forums where it appears to be acceptable behavior but this is NOT one of them . . I am in no way suggesting that all of the info he posts is inaccurate and he does indeed post very good info on occasions, but whenever ANYONE posts inaccurate info, including me, I think it is important to address it and get it corrected but it should be done in a polite and courteous way . . I also think that when someone makes unwarranted posts like his, they deserve whatever type of reply someone wants to make . . It's simply not polite to talk down to people like he did and I'm confident that we all have had enough crap in our lives that we don;t need anymore, especially on a site that is supposed to be FUN.

If you read posts carefully, using simple logic will often prevail and help you weed thru the superfluous to get to a reasonable and logical answer.

There are sometimes more than one way to achieve a specific goal, and this can sometimes be confusing, so as I mentioned, when reading info, it is always best to check additional sources to see if they say similar things so you have a general consensus that agrees.

One of the reasons that virtually any head can benefit from careful minor porting is the fact that no matter how perfectly a port is designed, it is physically impossible to manufacturer it as designed . . I know this for a fact because I worked at a manufacturer where they did these things.

If a perfect port could be cast, most of the cylinder head porters might be out of a job and the sale of CNC and putty porting machines would drop considerable because there would simply no longer be much of a need for them.

This is an example of what I mean by trying to use simple logic to try and come to some type of reasonable answer.

If you look t my comments regarding the Magazine test, it should be obvious why you can't trust them . . They started the dyno test way too high and left out critical information . . Look at it this way, for ANY test to be valid, it must produce repeatable results . . It is impossible to produce results that will match the ones in the Magazine because they did NOT provide enough information, therefore, without knowing exactly what the missing info is, it is simply impossible to consider that test to be valid.

The next things one should ask themselves are the following.

1. Since most dyno tests begin between 2500 rpm ad 3500 rpm, why did they start theirs at FOUR THOUSAND SEVEN HUNDRED . . I for one have never seen a dyno test on a 6500 rpm street engine started above 3500 . . You can search the internet from now until doomsday and will probably never find another like it.

2. They bought the pats so they now EXACTLY which ones they used and know ALL the cam specs because they are printed on a card tha comes with every single cam made by every single cam mfg, so why did they leave out the other aspects of the cams I mentioned?

3. A major part of a Magazines income comes from advertisement so it never hurts to consider who a magazines biggest ad buyer is when reading tests like that or consider which mfg gave the Magazine the most free parts etc.

Ya, thank's I'll give them a try. Actually, they are located about an hour or so from me.

I really want to try this instead of the performer that I have on now. The port size difference looks huge. It should make quite a difference.

Dan Jones's and his friend did a dyno test comparing several intakes including that one and I have the link to that info and will post it for you shortly.

 

[jpaz]

Thank's barnett468, I would be really interested to see that. I have searched everywhere for some kind of comparisons.

 

[Jeff73Mach1]

I know nothing. I just haven't been insulted lately so I'll share what I don't know.

The 4V Cleveland head is pretty darn good as it came from the factory.

Porting it could have some advantages if done correctly, but I elected to leave mine stock in that regard and simply focused on the valvetrain. My theory was that while I might get more power by porting, that with the right selection of parts and careful assembly, I could get more power than I would ever need on the street. Stroking for more cubic inches and internal balancing paid major dividends.

I don't know if the 4VCC heads are magical in their perfect design, but with enough compression and cam, I think they are pretty damn far ahead of the other brand offerings.

I won't tell you to listen to me or anyone else on this thread. 400-450 horsepower is easy to get to the rear wheels-making it work on the street in a 71-73 mustang is far more challenging.

Building a high performance motor isn't a secret anymore-building one that will live in a daily driver and still perform at a high level seems a bigger challenge to me.

 

[barnett468]

Thank's barnett468, I would be really interested to see that. I have searched everywhere for some kind of comparisons.

OK, here it is

CLEVELAND INTAKE DYNO COMPARISON

http://pantera.infopop.cc/eve/forums/a/tpc/f/5650045562/m/994102665

http://www.the351cforum.com/viewtopic.php?f=3&t=82

HEAD PORTING INFO

First of all, i am in no way a professional cylinder head porter, however, I do know a few people that are and have discussed porting with them to some degree on several occasions . . i have also built many clevo engines . . i am also aware of actual back to back tests of stock heads vs ported heads, and in all of these tests, the peak hp was increased . . it is definitely possible that others may not have had the same results and if they didn't it is simply because the porting they had was different than the porting that was done on the tests i am aware of . . yo may have heard before that it is easy to screw a head up by porting it if it is not done properly and this is definitely correct . . porting is a science and the use of wet flow benches helps to actually see what is going on, however, seeing what is going on is absolutely useless unless understands what effect what they are seeing will have on performance.

below is a comment from Jon Kaase . . He has won the annual engine masters challenge 5 times so he has established his credibility and you will notice that he did a back to back test on a head where it had turbulence that reduced flow so he tested it that way then corrected the turbulence which greatly increased flow but it didn't increase power and he has absolutely no idea why . . if a guy that won the biggest engine building challenge in the world whom was also the engine builder for a top NHRA driver has absolutely no idea what happened in his test, it shows that this stuff is not easy and what would seem logical and may work on paper just may not work that way in actual application when the engine hits the dyno or the tires hit the pavement.

"In 1975 I bought my first flow bench, a used bench top Superflow. The first head I checked was a ported 351 Cleveland 4-V. Of course it went turbulent at .700". Well, 31 years later I still don't have all the answers for this problem. I am once again faced with it in our SCJ and P-51 Ford big block heads. I know right where it's at; looking down the port on the right side of the floor at the short turn the air won't follow the turn and breaks away and tumbles. If you wet flow it you can see the air circle around in the chamber and go back in the valve bowl. It might be an area about 1/2" wide at the seat. I've never seen it in a Hemi or Pro Stock head because the ports are higher and don't make as severe of a turn. When the port comes in from down on the deck, and the head flows lots of air, and the port is configured like a Cleveland, it's one of the things that you run into. The big question (that I'm still trying to find the answer to) is does this really occur when the engine is running and if it does will is hurt the power? I'm sure there are ways to fix it that will lose power. With all the pulses and pressure waves and fuel mixed in the air going on in the intake port, who's to say? We take care of a Douglass Dauntless SBD-5 WWII dive bomber that belongs the Confederate Air Force. One day I noticed an air channel that goes from under the front of the wing and exits at the top of the back of the wing. The guys told me that during high angles of attack, it put air back in the place where it goes turbulent. It makes the control surfaces still work. You know where I'm going with this! I came home and went to work on some SCJ heads. I installed a 5/16" thin wall stainless tube that went from the intake floor through the water jacket and exited just above the seat ring, right at the point where the air breaks away. It went right through the short turn rise, parallel with the deck. It completely cured the turbulence. I did all 8 ports. With the hole open they all flowed about 410. With the hole plugged, they backed up and flowed about 375. When I dynoed it, it made 750 with the holes open. Then I put little plugs in the tubes, and it still made 750. I went back and forth 2 more times. it just didn't matter. From 375 to 410 CFM at .600" and it made no difference. So does it really happen when it's running? I still don't know for sure! ... Kaase"

STOCK VS PORTED DYNO RESULTS

Below is just one of several back to back cylinder head porting tests that shows an increase by simply porting the heads . . Even though two different sets of heads were used, it is still a valid test because in stock form, both sets of heads are basically identical . . A Boss 302 head is basically a 4V Cleveland head that Ford put on a 302 engine or vise versa.

The increase in power by simply increasing air flow was a whopping 54 HP and 24 TQ, and the hp increase was achieved with just a tiny 200 rpm increase.

The Boss 302 heads were ported a fair amount but not as much as they could have been, so even with the moderate porting that was done, there was a big increase in hp and tq.

A 1 point increase in compression will increase hp and tq everywhere by around 3.5 - 4% . .

CAM ................................ Crane Hyd Roller p/n 529801 . 290 294 . 228 232 . 597 609 . lsa 112

COMPRESSION ............. Max of around 10.2:1 but may have been slightly different between heads.

ROD LENGTH ................. 6.0

INTAKE MANIFOLD ........ Stock cast iron 4V Cleveland with 1" spacer.

CARBURETOR ............... 950 cfm

ENGINE .......................... Cleveland stroked to 383

HEADERS ...................... 4 into 1 with 1 3/4" tubes 3" collector

DYNO TYPE ................... DTS

TEST a. - STOCK UNMODIFIED 4V HEADS CHAMBER AND VALVE SIZE UNKNOWN

TEST b. - PORTED BOSS 302 HEADS CHAMBER AND VALVE SIZE UNKNOWN IN FLOW 325 EX FLOW 234

TEST c. - INSTALL TUNNEL RAM ON SAME BOSS 302 HEADS

a. HP 432 @ 5700 .... TQ 439 @ 4000

b. HP 486 @ 5900 .... TQ 463 @ 4800

c. HP 523 @ . N/A .... TQ 476 @ . N/A

.

 

[barnett468]

.

The 4V Clevo head does work great just as is and few will argue against that, but the design of ALL cylinder heads on high perf old school engines is limited/restricted in design due to hood clearance and shock tower clearance . . For optimum performance, the air should go straight in the cylinder without making ANY turns and should exit the same way, but this is obviously not possible on these cars, therefore, cylinder head design was ALWAYS a compromise on these cars and the Clevo heads are no exception.

The exhaust port on a Clevo actually SUCKS, lol . . They made a huge port to get the exhaust out but then FORCED it make a 90 degree turn as soon as it exits which had to be done to make the exhaust manifolds clear the shock tower . . I guarantee you that the engine designers did NOT want to do this . . Engine designers HATE hoods and shock towers and want to do nothing more than build the highest powered engine they can without constraints or limitations, and being forced to make compromises due to space limitations might be an interesting challenge for them, but it is not what they prefer to do.

You can alter how a Cleveland head works without porting it by installing bolt in exhaust port "stuffers" . . These have been proven to increase power by a little in some applications, however, they ain't cheap . . You can buy them in the link below . . The curved ones will work the best.

http://www.mpgheads.com/port_plates_a.php

As far as the intake port goes, there is a few different things you can do, but some of these simply alter the power . . This means that they will improve performance in one area but take away from it in another, therefore doing these mods is definitely helpful in some apps but is detrimental in others.

All of these mods can be reversed so if you don't like what they do, just remove them.

1. Install 2V sized port shims on V heads if you can find them . . They may have been discontinued . . I had these on an engine and although it is a horrible thing to do to an intake port because they create a lot of turbulence when the air from the intake runs into them, they do tend to reduce the "bog" that is common with 4V Clevo heads on stock engines and the car ran great, BUT, it did not haul ass.

2. Install an Eddy RPM 2V/4V intake . . The ports are smaller than those on a Clevo but it smooths out the power and works really well.

3. Parker Funnel Web intake . . This is too tall for a Mustang so it is a moot point but it has been proven to work well on them but is not the best intake for high revving engines . . The RPM intake is probably the closest to this one in performance but it will fit under most hoods . . If it is a little too high a drop down air cleaner and/or an RPM intake ca be used..

4. Parker Funnel Web intake with intake port stuffers . . This combo works better than just the Funnel Web intake alone.

Photos and Web site

http://raceabilene.com/kelly/hotrod/funnelweb.html

This is a cut away of an unported 4V Cleveland head and Parker Funnel Web intake.

.....................................

This is with his intake port stuffer added.

.....................................

......

.

 

[jpaz]

Wow! That's a lot of info. Thank You for posting all that. Just to be honest, most of it is above my level of knowledge. I'm sure it will be very beneficial to many.

I just should have gone with this or the Air Gap. I didn't really know about the Blue Thunder & I just didn't like the look of the Air Gap. I got the Performer real cheap, so I just went with that.

So now, without porting, will the Blue Thunder out perform an Air Gap? I have a warmed over 72 Q code, nothing fancy 4v heads, larger than stock cam (not sure of specs from PO rebuild). I changed carb to Holley 770. Better than it was w/stock carb & manifold, but I think a better manifold would help. The rpm's just die out way to quick.

Anyway, Thank's again Barnett! I'm still learning.

 

[barnett468]

Wow! That's a lot of info. Thank You for posting all that. Just to be honest, most of it is above my level of knowledge. I'm sure it will be very beneficial to many.

I just should have gone with this or the Air Gap. I didn't really know about the Blue Thunder & I just didn't like the look of the Air Gap. I got the Performer real cheap, so I just went with that.

So now, without porting, will the Blue Thunder out perform an Air Gap? I have a warmed over 72 Q code, nothing fancy 4v heads, larger than stock cam (not sure of specs from PO rebuild). I changed carb to Holley 770. Better than it was w/stock carb & manifold, but I think a better manifold would help. The rpm's just die out way to quick.

Anyway, Thank's again Barnett! I'm still learning.

LOL, no prob, glad you found it interesting . . As I mentioned, I definitely don't know it all, and many others know WAY more than I do, but I do at least know a few things having been building engines and restoring cars for over 40 years . . W all started out knowing nothing and some of us just learned different things over the years.

Although the dyno results below ar done on a 408 Cleveland, the results can still be applied to a 351 to a certain degree.

The AIR GAP made more overall power below 5300 rpm and the BLUE THUNDER made more above 5200 rpm, so it depends on your driving style as to which one is really the "best" . . If you never race and want killer bottom end and mid range power, the AIR GAP will absolutely be better than the BLUE THUNDER, however, it is not always about getting every single hp one can out of an engine . . Sometimes people buy an intake simply because they like the look which is perfectly fine because none of us are going to race our cars in the NHRA Nationals.

BLUE THUNDER STANDARD INTAKE

RPM HP Torque (ft-lb)

4000 369 483

4100

4200 391 489

4300 403 492

4400 414 494

4500 425 496

4600 436 497

4700 447 499

4800 458 501

4900 464 497

5000 462 485

5100 464 478

5200 478 482

5300 488 483

5400 498 484

5500 505 481

5600 503 473

5700 504 465

5800 511 463

5900 519 462

6000 526 460

6100 507 437

AIR GAP FOR 2V HEADS . The do not make one for 4V heads but it fits 4V heads . . Do NOT port match this intake because it can reduce power.

RPM HP Torque (ft-lb)

3900 383 512

4000 387 509

4100 396 508

4200 408 509

4300 416 509

4400 425 508

4500 435 507

4600 445 508

4700 451 505

4800 466 507

4900 466 500

5000 468 492

5100 474 488

5200 481 485

5300 484 480

5400 487 473

5500 489 467

5600 487 457

5700 490 451

5800 495 448

5900 501 446

6000 494 432

 

[jpaz]

More great info Barnett. Looks like maybe the air gap would probably be my better choice. I thought after seeing how much bigger the ports are on the Blue Thunder that it would work better, very interesting.

I'm just street driving, no strip, but I do like to roast the tires every now & then. Plus I gotta try keeping up somewhat with all these new hot rods coming out of the factories! (not a chance lol)

 

[barnett468]

More great info Barnett. Looks like maybe the air gap would probably be my better choice. I thought after seeing how much bigger the ports are on the Blue Thunder that it would work better, very interesting.

I'm just street driving, no strip, but I do like to roast the tires every now & then. Plus I gotta try keeping up somewhat with all these new hot rods coming out of the factories! (not a chance lol)

Yeah it sounds to me like the air gap will be better overall for your app to me to . . the rpm is very similar but slightly lower if you need more hood clearance, and if they make one of those for it, that would be another option.

Its extremely easy to fall into the thinking that bigger is always better . i have been there and done that, but eventually learned better along the way.

air flow vs potential power is an incredibly complicated subject that a only understand a bit of but you need both for optimum perf so a balance must be struck between the two.

in general, the more air the heads flow, the more horsepower the engine can make and the faster the air flows, the more torque it can makes . . since these two factors are intertwined, it makes it difficult to achieve the ideal balance for ever app.

one issue is this . i you had a head with a 4 inch intake valve and 4" x 4" port on less than a 10,000 cubic inch engine, the air would nter the cylinder so slowly that there would not be enough vacuum to suck the gas out of the carb and even if it did, suck some out, the gas would not be mixed with the air [atomized] and therefore might not even ignite, lol.

the smart people are not people like me that simply buy existing parts and bolt an engine together with them . . the smart people are actually cylinder head and intake manifold and camshaft designers.

 

[jpaz]

That make perfect sense to me when you explain it like that. I am somewhat of a mechanic, so I do understand. For a 150 bucks more I can keep a more stock look, but get a little lees all around performance. lol

I agree though, the engineers that design & make all this stuff work are brilliant, & you are no slouch either.

Omie01, I hope your getting all this!

 

[barnett468]

That make perfect sense to me when you explain it like that. I am somewhat of a mechanic, so I do understand. For a 150 bucks more I can keep a more stock look, but get a little lees all around performance. lol

I agree though, the engineers that design & make all this stuff work are brilliant, & you are no slouch either.

Omie01, I hope your getting all this!

oh, you didn't mention you wanted a stock look . . that is no prob . . this "cheater" intake from scott cook looks IDENTICAL to a factory one including factory part number and a date code and the Cleveland Foundry logo but it is aluminum and flows way more . . darrin morgan of rehr morrison racing engines helped in the design.

Is there anything else i can do for you today?

http://www.scmenginedevelopments.com/manifolds.html

FACTORY CLEVELAND 4V.

 

[jpaz]

Killer, wish I could afford that.