|01-10-2013 01:32 AM|
Also makes me wonder why bother w/any small displacement engine to build, boosted or not unless that's absolutely all there was available, or if it was original equipment in a car, like the 5.0 Fords.
I guess some do it because they think it'll be cheaper starting w/an engine they may already own. But buying a suitable core is the cheapest part of the build- even throwing out an ill-suited engine and starting fresh would be a better choice in many cases than building up an engine that was short on displacement.
I do not subscribe to the whole "bolt a blower on a cammed-up stock short/long block and when it blows, go get another one to blow up the same way, repeat as needed" theory. Nor does it always have to be a top-shelf build in every regard although it would be nice to be able to do that, budget be damned.
If a guy chooses his parts carefully, looks for deals, and doesn't hurry into too many mistakes or follow poor advice, a decent engine can still be assembled using good parts that'll perform great and not break the bank.
And I draw the line at 305 heads. For me installing 1.94" valves is the deal killer. In a tight budget situation I'll still port the old fuelie heads, but only because I have all the templates and valves I made to use as tools to get a semblance of uniformity between the ports. The labor to port a cast iron head is much the same regardless of what head it is. I'd rather have a stock L31 Vortec head than any of the others, anyway. They have no shortcomings for use on a performance 350 that cannot be dealt with cheaply. That said, there are guys who won't even mess w/fuelies OR Vortecs. And that's OK by me.
On a final note, I'd like to say that oversimplification and 'one size fits all' "advice" helps VERY little and may well cost a lot more in the long run. And unfortunately it's always the new inexperienced guys who buy into this type of short-cut advice, because it makes it sound so damned easy. It's what they want to hear, not what they NEED to hear.
The net result of this is often going to be disappointment when it's found that it takes some actual thought and understanding of the fundamentals- and beyond- to get as good of a result as the oversimplified short-cut answers promise. In other words, building a street/strip engine correctly for the application might not be rocket science, but it sure as hell isn't THAT simple, either.
|01-06-2013 08:41 PM|
"All I know is what I learn from talking to the engineers and racers who run this stuff. Blower Drive Service says that they have consistently had better results on gasoline with a 110 LSA, so that's the info I pass on to others who ask. They say that you may want to open up the LSA for alcohol, but tighten up to 110 on gasoline."
You posted my quote, but erased my screen name from the top of it. What kind of nutball does that?
All I'm asking is that you LEAVE ME ALONE. Post what you think to be the truth and I'll do the same. I have never jumped into the middle of your stuff, unless it was to defend myself from one of your scathing attacks.
You're a freakin' ding-dong. Nobody has done everything themselves, not even the premier engine builders and certainly not you or me.
I'm asking only one thing. LEAVE ME ALONE. It's no fun to have to answer your attacks instead of helping the younguns on here who ask for help.
|01-05-2013 12:40 AM|
I dont understand why someone would use a blower for a 4-500 HP engine? I would use almost any LS engine with a hot cam,or any 350 gen 1 with a good blue print and well chosen parts.
Tech,one thing about your choice of parts is the meticulous detail and parts matching.I think that is money/time well spent.
I do prefer to use slightly bigger cams than you recommend. I also prefer solid cams over hydraulic.( Ive never purchased a roller hydraulic)
|01-04-2013 11:37 PM|
First me then Richard.You are very argumentative and defensive. Just the facts.When I find overall a member on a forum doing that,it is surely due to the fact of having no real world experience.
When you post a last picture to boost your position and it doesn't have any connection to you.If I see that,don't you think everyone else does??. That's playing a kid's game.
When you have danced around turn key costs,if your so knowledgeable,I would think you would know what that current cost would be. You change in another post to three different model blowers to fit you "ballpark" pricing.Here again your info was flawed and again I caught it and so did everyone else.
Guys that have done things before,you see that in their posts.Both Richard and me have been exposed to that kind of knowledgeable forum member and you don't see all this defensive posts.
Then you portray this mystery tune up which has to be right so you can do anything you want,well no details makes a bigger case of you not having any experience at all.
You got to know your playing around with other people's money.Right??.
Then a case of you NEVER BEING WRONG just caps it off.I mean really??. NEVER??.
So this real world experience,I doubt that.
Your creditability has been more damaged by your own posts than anything any of us have said.
I wanted to stay put of this thread because I knew you would ruin it for the O/P as you have.
|01-04-2013 05:46 PM|
BDS does not differentiate between the source of the compressed air, whether it be from a 6-71, 8V-71, 4-41, 3-71, 144, 177, Latham Axial Flow, air bottles (per Mickey Thompson) or whatever. And the camshaft has no idea who or what compressed the air and it does not care. All it knows is how to tell the tappet what to do based on the lobe profile.
So don't come here with more of your half-baked opinions, telling me that I took something out of context just because it seems that you will go to any lengths to disagree with me. Even when I try to agree with you and use some of your suggestions, you go the other way. Case in point was the blower on a BBC a few days ago. I suggested that the OP might take a page from your playbook and bolt a blower on the motor. You came right in behind me and said that the motor was fine as it was, naturally-aspirated. I guess what I'm seeing is that emotionally, you're a tiny little person.
You are transparent and predictable and if you want to start calling me on stuff again, remember, I can play the same game. I though that after I blew up on you the last time, that you would play nice and leave me alone. Do I have to start in on you again??????
"Choosing the proper camshaft would be the most important requirement for a blower motor. An improper cam will cause a variety of problems that can easily be avoided by following a few simple guidelines. Hydraulic cams are recommended if you intend to drive the vehicle frequently, requiring little or no maintenance, and the maximum engine RPM's are kept around 6500 or lower. Roller rocker arms are recommended. Flat tappet and roller cams are recommended for high performance applications especially where the engine will see high RPM's. Exact camshaft specifications vary depending on the performance level you wish to attain. BDS offers different types or stages of cam grinds specifically made for blower motors. Refer to camshaft specs listed in tech info for BDS' individual engine camshaft specifications and their intended uses.
If you wish to purchase your cam from one of the many fine camshaft manufacturers, we suggest using our camshaft specs as a guidline. Extremely high lift and long duration cams are recommended for high RPM, high performance racing only.
The lobe center of the cam will play an important role in determining the performance characteristics of an engine. Wide lobe centers (112 to 114 degrees etc.) will create higher cylinder pressure providing more horsepower with cooler burning fuel such as alcohol and methanol. We have found 110° lobe centers to produce the best overall power on gasoline.
Whatever cam you choose, make sure that it will operate and perform properly in the RPM range required for your application."
|01-03-2013 09:26 PM|
I wouldn't hesitate to use a 300hp cam with a small blower. Now, if you were to get serious with a 6-71 or 8V-71, then yeah, I'd want to stab another cam in there and re-piston the motor for forged and 8.00:1 or lower SCR.
|01-03-2013 09:09 PM|
12-400-4 - Blower & Turbo Hydraulic Flat Tappet Camshafts
It does not appear the current cam will be bad. Certainly not as bad as the 30-30 cam would be. But would the added midrange of this cam make it worth it to swap out. I dont do too much with roots style blowers. And never with smaller cams.
|01-03-2013 08:34 PM|
12-670-4 - NOSTALGIA PLUS Hydraulic Flat Tappet Camshafts
|01-03-2013 08:25 PM|
By the 327 300 cam do you mean the gm 30-30 cam. Because that cam is not good for a blower motor. You may want to go with a nice roller setup for blower it will make ot pop off like you want. The large over lap cam will not snap like one setup for a blower.
You either want to run a efi cam or a cam made to work with a boosted application.
Look at the power output this way. If you have 14.7 psi of boost you will be adding another atmosphere to the engine. And in therory that should double the hp output of the engine. So back that down to 5 psi and you can guestamate how much power the engine will make. Subtracting for loss and the 25 to 50 hp needed to turn the super charger.
|01-03-2013 08:01 PM|
300 times 1.25 = 375
300 times 1.4 = 420
To use 8 lbs on pump gas, you'll need a 8.0:1 or less static compression ratio.
To use 7 lbs on pump gas, you'll need a 8.5:1 or less static compression ratio.
To use 6 lbs on pump gas, you'll need a 9.0:1 or less static compression ratio.
To use 5 lbs on pump gas, you'll need a 9.5:1 or less static compression ratio
To use 4 lbs on pump gas, you'll need a 10.0:1 or less static compression ratio.
I would make a phone call to Weiand and find out what their recommendation is for ring end gap and piston to wall clearance.
Look into some kind of ignition retard that changes with boost changes.
|01-03-2013 07:43 PM|
|vinniekq2||probably 80 or 90 plus HP with no other changes. round it off to 100 if it sounds cool|
|01-03-2013 06:32 PM|
144 blower on 350
I have a 350 crate engine 290hp with a 327 300 cam making
300 HP and wanting to add a b&m 144 blower and was wondering how much of a HP gain will I have and make on my set up...and how much is a used 144 worth (Xmas) present