Anyone tried a 4/71 blower on a RV8 4.6 engine??

perrymgbv8 · April 05, 2011, 04:15:06 PM

As per the title!
Any comments??

Regards
Perry

perrymgbv8 · April 05, 2011, 05:03:10 PM

-- moved topic --

roverman · April 05, 2011, 07:08:42 PM

Perry, Close "roots", but no dyno time. How much boost ? Hard part will be, mounting on what intake manifold ? I went with 6V-71 because: a, $200 new b, "Dyers' Blowers" makes an adapter casting that fits/welds onto Offy single plane, int. man.ALL diesel blowers MUST be modified for gas/alcohol use, and the much higher rpm., they will see. "Superchargers USA", prepped mine, and claim it will make 20 psi all day, on 290" Rover. Good Luck, roverman.

7sand8s · April 05, 2011, 10:33:27 PM

http://blowerdriveservice.com/cart/ymm.php?cat=9_64
http://blowerdriveservice.com/cart/index.php?main_page=product_info&products_id=1028&cPath=64

perrymgbv8 · April 15, 2011, 03:33:55 PM

The 4/71 build is underway. This is a mock up on a spare engine.
I only intend to start at around 8psi of boost while I figure out how this thing will behave.
Once it is settled in on the engine I'll get it on the dyno for basic testing. Ideally I want the blower to make around 120hp extra. Then I can start adding nitrous for some charge cooling and a little extra power

roverman · April 15, 2011, 05:37:16 PM

Perry, You bought a BDS manifold to fit ? roverman.

BlownMGB-V8 · April 16, 2011, 01:48:48 PM

Is that an iron block by chance?

JB

bigaldart · April 20, 2011, 07:44:07 AM

Perry,

For what you are looking at about 15% underdrive will get the job done and will make around 50% more power than N/A. Blowers and Nitrous are a good mix due to the intercooling effect of the nitrous. Buy the Pat Ganahl book and pay attention to the blower clearances and It will last a lifetime on that motor. For reference with 16 psi on a 3.5 we make around 400 hp on methanol.

Alan

perrymgbv8 · May 07, 2011, 06:34:18 PM

Its a BDS manifold and the trail fit tonight looks ok

BlownMGB-V8 · May 07, 2011, 08:25:35 PM

That's pretty cool Perry. I ran 16+ psi through an intercooler on a 215 and it made just gobs of power. But I was running it on standard premium with stock cast pistons and got a bit of nibbling around the edge of one piston. That was with an Eaton M90 blower and about 2:1 overdrive. I don't know exactly how your 4/71 compares... 284 cu.in. displacement I guess, which should be about right for the motor, it's obviously a good bit bigger than the Eaton but I was trying to keep it somewhat compact.

Anyway, I think you're really going to like that engine. It's great that a few of us have decided to go down the blower path and I think we should stick together. Bill Jacobson has a very nice build, very techy with his engine management package and individual egt's. I like intercoolers a lot and hope to have my new engine running by mid to late summer. It'll be kinda special.

JB

perrymgbv8 · May 12, 2011, 06:27:57 PM

Hi Jim!
Thanks for the support.

Here she is on the trailer this evening ready for testing tomorrow and Saturday

BlownMGB-V8 · May 13, 2011, 08:40:23 PM

Really looks good Perry. Can't wait to see the results!

JB

MG four six eight · May 15, 2011, 12:08:48 AM

Nice! :-)

Bill

perrymgbv8 · May 16, 2011, 03:42:55 PM

Hi guys!!

I'm very happy with the results so far

I'm only running 7psi of boost and she did very well once I learned how to get her off the line. It still felt very lazy though??

She ran 11.8's on the 1/4 mile with this setup. So I'm happy as its only 1.2 seconds slower than my old 300hp of nitrous setup.

Although i now think my th350 is slipping as I was crossing the finish line at only 117mph at 5500 rpm. I used to cross the line on nos at 5200 rpm at 127mph. This is a real problem I think as I did have trouble finding drive and the manual shifts were very lazy?? Bu this old 350 gearbox has been abused for 6 years now so I guess it has a right to complain huh?? I have peaked this stock gearbox on the dyno at 402 bhp @ 540 ft/lbs on a 300 shot of gas. And its had two years of 1/4 mile runs on that setup, so about 80 passes on the strip.

I do have a spare th350 with transbrake that I got on ebay. And it is supposed to be a refurbished unit... Time will tell I guess ...

Here she is waiting to stage for a no burnout test pass.

And here she is doing a test run againt a friend of mine in his Cortina who is running under par from his usual 8.8 passes while testing a new fuel system.
http://www.youtube.com/watch?v=oVZOipaSMTA&feature=youtu.be

Moderator · May 17, 2011, 12:02:40 PM

You're looking fantastic!!!

perrymgbv8 · May 18, 2011, 07:53:36 AM

Thanks Curtis

I'm happy with the whole concept as well. And I do like the general stance of the car now.. I just need to get back into the good numbers on track now to go with the looks

Regards
Perry

MGBV8 · May 20, 2011, 08:36:13 AM

Awesome!

Junk the TH350 ad get a Powerglide.

perrymgbv8 · May 22, 2011, 01:47:05 PM

Hi Carl!
Do you think a glide will be better?? Do you have one??

I'll consider any upgrade thats makes it better

Today I'm adding the direct port injectors so I can spray under the blower with a small shot of gas.

roverman · May 22, 2011, 02:16:09 PM

Perry, you"might" want to consider a C4. If you shop around, you'll find there's some very serius drag cars running them. Lower first gear than a glide' and less drag than a turbo 350. I like the separate BH. of the C4. Good Luck, roverman.

mgb260 · May 22, 2011, 04:31:56 PM

Art, I agree with you and Carl. Both are the best for racing with the edge going to Powerglide because of only one shift. Also C4 with pan dipstick has better internals than case filled. Summit and Jeg's have parts for both. Powerglide can be cut off and use bell that mounts to front pump.Kennedy used to have an adapter for Rover to 64 and later GM bell. You can get adapter plates and bells from GM to C4 also. Compare costs.

BlownMGB-V8 · May 23, 2011, 09:01:34 AM

Perry, if you're not aware, everything used in a drag racing powerglide is available from aftermarket suppliers like Summit. Various cases, all the internals, valve bodies, vastly beefed up parts, etc. Long history and tons of aftermarket support.

JB

perrymgbv8 · May 26, 2011, 03:32:13 PM

Thanks for the heads up Jim

perrymgbv8 · May 29, 2011, 11:15:11 AM

Good results from the dyno yesterday.
The blower made 7psi and I had the ign set at 19 degree's of max advance. She pulled a no drama's run on the dyno with 335bhp and 468ft/lbs of torque. Fuelling from the stock Edelbrock 800 was rich up to 2000 rpm and then leaned off to almost perfect at full pedal. A top up of tranny oil seems to have lost the apparent slip as she made a wheel speed of 142mph at 5700 rpm.

Now I have a starting point to tune from. Next job is another pulley to see if I can tweak it up to 10psi and then add a sniff of gas from the direct port injection I've just made.

perrymgbv8 · June 05, 2011, 04:27:25 PM

Great results from the track yesterday. After messing over 5 test passes with ign timing I found the sweet spot for the 7psi of boost and she now runs 11.7's with the tune..

I'm very very happy with the results so far.

60 foot times are only 1.7 and 1.8 which is a little off my old 1.5's and I cant believe how calm she feels off the line even though the 60 foot times are only around 0.3 of a second slower.

I have already ordered my new pulley to go up to 10psi of boost so I can do more testing.

perrymgbv8 · June 29, 2011, 03:31:47 PM

More dyno results!!!

I fitted the 10pis pulley and added fuel and she pulled 350hp with 503ft/lbs on the dyno last Saturday.

I am leaving the tune as it is for now. I want to take it for testing this next weekend. I have 2 days of track time to play.

I still have my old nitrous system fitted and ready to rock. But I dont think I'll be adding an extra 450hp of gas anytime soon

I made 11.7 with the 7psi setup I'm hoping to go low 11's with the 10 psi ?