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Topic Review (Newest First)
01-23-2013 11:50 PM
1932bantam way to much mass out front blower is already puttn a strain on the end without that damn big counter weight on the end of the crankhub then adding pulleys to turn other things really puts it out there. externally balanced I stay away from. blown or not
01-23-2013 08:28 PM
496CHEVY3100 A Properly machined and preped 4 bolt with aftermarket caps or straps,ARP studs in mains ,arp cap screw in good prepared forged rods ,something like C&A bearings ,high quality pistons ,good solid roller cam with maching springs & kit will live at that level.when i say Live engine producing this much horsepower has a SHORTER life than say 400 hp Also i think a $1500 assembly will not cut it.
01-23-2013 07:50 PM
strokin I do have a mid 70's block 4 bolt never been bored that I can use for this build, but just thought when buying a $2000 rotating assembly is another 1500 for a block to protect it all that much? Will a mid 70's 4 bolt take 650 hp? I would think so but always that hint of doubt. Also u mention 8-71 on sbc, is that not to big for sbc? This is all going in 87 monte ss 9" 3.89 spool, coilovers, 8 point cage, notched frame, 3" exhaust with 1 3/4 hooker headers. This car is mainly for show and street but does hit the track a few times a year. Only drive it 2 times a month if I'm lucky.
01-23-2013 06:40 PM
496CHEVY3100 Normaly the crank is not the weak link, the bolts and caps usually give up and crank gets blamed ,i agree with F bird on 383 ,mine is a two bolt big block ,but i have arp studs not bolts also billett caps knife edged crank,lightned and balanced with mallory I dont anticapet any problems with 7.9 cr alum heads and pump gas, Streetdriver, if you see this on trailor report it stolen.
01-23-2013 06:00 PM
vinniekq2
383

Quote:
Originally Posted by F-BIRD'88 View Post
A 383 crank has a inherently bad design characteristic. I won't use them in a 6-71 or 8-71 roots blown
motor, specificly, because of this. I'll build a 355 (thats just as powerfull and more reliable) or a 4.125" bore 400 block based 377 or a 406. Or go 427-454 BBC based.

I'd trust a stock cast GM 350 crank more than a 383 stroker crank in a roots blown application.

Engine builders will sell you what ever you want, cause thats what you want.
If they don't or won't, the next shop down the street will...so...

But....

If someone comes to me and wants me to build them a 383 stroker motor for a roots supercharger, I will pass on it. No thankyou.. I'll offer to build a equally power full 355 based roots blown sbc motor or a roots blown BBC or not at all.
first question, "why"?

second question: how do "you" build a 355 equal in power to a larger 383?
01-23-2013 01:23 PM
cobalt327 That's my point. A 383 crank is not inherently bad. There are good and bad "383" cranks just like there are good/bad cranks of any stroke for any engine.
01-23-2013 11:24 AM
cobalt327
Quote:
Originally Posted by techinspector1 View Post
Read this from Blower Drive Service...

"Flat tappet and roller cams are recommended for high performance applications especially where the engine will see high RPM's.
I'm thinking they left out Solid lifter, as in "Solid lifter flat tappet and roller cams are recommended for high performance applications especially where the engine will see high RPM's."

As long as the crank is good quality, there's not a thing inherently "wrong" w/using a longer stroke.
01-23-2013 09:48 AM
1932bantam yes i agree . he already had engine , so we tried it
01-23-2013 09:39 AM
vinniekq2 Many reputable crate engine builders will build 383/406/434 turn key blower engines.They use a callies crank.Just dont try to build powerful and cheap,leave that for the low horse power guys
01-23-2013 08:42 AM
1932bantam thing about the 400 you got to run that big heavy crankhub for ex balanced that and pulleys for alt etc. puts alot of strain on the end of the crank. As far as quench no need to worry about it on a blown engine. We just had a crank hub twist off, bent end of crank on 383 idling was running a spacer behind blower pulley, not a good setup
01-23-2013 08:00 AM
496CHEVY3100
Quote:
Originally Posted by techinspector1 View Post
I'll bet your Comp "blower cam" is cut on a 114 LSA. Read this from Blower Drive Service...110 works best for gasoline...114 works best for ALCOHOL...

"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."

I don't know what it is that makes you guys jump up and buy the cam as one of the first items. Cam and torque converter should be the last 2 items bought, after you've finished the drivetrain and everything else.
Thanks Mine is 110 lc hydi do have roller rockers& All matching parts and only 540 lift ,the alum heads i buught are good up to 615 lift as recomended by comp far gas ,114 for alcohol, compresssion is 7.9 converter is 26 00-2800 from B&M for big block app,all i want is the whine of 671 ,will nerer be raced exept to gas station ,lol,probable never over 5000 rpm. just want look and sound thanks for advice.. i had the converter still in box 4 yrs and blower before i bought the engine
01-22-2013 07:10 PM
vinniekq2 after market dart blocks are great. 400 is a good starting point for your engine
01-22-2013 06:35 PM
strokin So you don't see any advantage to running a 400 vs 355 even though they will all be brand new parts? Obv we've all heard of typical problems with a 400 but even with dart block and all aftermarket parts?
01-22-2013 06:29 PM
strokin Ya I've heard about running wider gap, but yet some say to run a second gapless ring?
01-22-2013 05:26 PM
techinspector1
Quote:
Originally Posted by 496CHEVY3100 View Post
have already purchaced Comp Cam Blower Cam
I'll bet your Comp "blower cam" is cut on a 114 LSA. Read this from Blower Drive Service...110 works best for gasoline...114 works best for ALCOHOL...

"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."

I don't know what it is that makes you guys jump up and buy the cam as one of the first items. Cam and torque converter should be the last 2 items bought, after you've finished the drivetrain and everything else.
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