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Does this sound like a good street build?
I’m in the planning stages of my rebuild of a ‘72 RB440 engine from my Jensen. Never having done this before, I’d really value any input / advice or alternative suggestions! Stroker kit in 500, 505 or 512ci ( undecided so far....) from either Eagle or 440 Source. Trickflow Powerport 240 heads. 3/8” pushrods (or stick with standard diameter?). Crane HR222 hydrualic roller cam (or maybe HR230, but I need lots of vacuum so maybe a bit lumpy?). Harland Sharp 1:5 ratio roller rocker set S70015K or T & D steel set (big price differential, worth it?). I’m after a compression ratio of about 10.6 - 10.9 : 1 with the alloy heads which I understand will actually be one full point lower in practice and about as much as fuel in th UK will allow without detonation. I already have the following ready for the build: Edelbrock Performer intake manifold (no room in engine bay for anything taller!). Fitech 600hp EFI system with Aeromotive Phantom 240 fuel pump system. CVR water pump housing with Milodon high flow pump and 160 degree thermostat. Milodon roadrace oil pan & stroker windage tray, with a 1/2” pick up. Milodon billet oil pump & cover with externally adjustable pressure regulator. Tubular 1 7/8” headers with 2.5” system. The block will be prepared by Hauser Racing here in the UK which I understand will include oil gallery mods, magnafluxing and sonic checking in addition to the usual machining. The car is going to be street driven only so must remain smooth and civilized, use oil like a modern car (if possible..,) and be bombproof enough not to need rebuilding for decades!! Thanks in advance guys! |
I would go with a 4.15 crank, no bigger, you can run into issues with the oil pickup tube. Also long turm plan I would not max out cubic inch displacement and you will be fine. Magna flux the block before machine work and do or have a quality blueprint done on the shortblock ,I would keep cr at 10 - 1.
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For a street motor I like the Comp Cams rocker asm., the Trick Flow heads are great!
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Thank you Iowan, Can you clarify what constitutes a blueprint on the short block? What should I be asking for from my engine shop? Is it the sort of thing Hughes or Muscle Motors supply of the shelf? Sorry, lots of questions! |
Nope, it's what the machine shop does to make sure your block is square and true, everything is is spec. etc..
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I like most of the build. But I don't think that for this purpose that I would do a 500"+ engine, like Iowan suggested.
The first cam is a good low end cam, and will work well, in my opinion. I think it will have good performance, Low maintenance, and enough power to move the Jensen pretty good.... :) Now if your looking to do a monster, 500+ is the way to go. But your going to be spending some time and money working on keeping all that H.P. in place. Sounds like a fun project... Keep us posted and up to speed on the build !!!!!! Best of luck....:) |
I think .030 over 4.15 stroke is only 495 Bob.
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The cost Difference between the 4.15 crank and turning the stock crank, 446 and 495, $600? The 495 is going to have 100 lbs/ft more torque.
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Originally Posted by Wreckless
(Post 143074)
Thank you Iowan, Can you clarify what constitutes a blueprint on the short block? What should I be asking for from my engine shop? Is it the sort of thing Hughes or Muscle Motors supply of the shelf? Sorry, lots of questions! Connecting rod length and big end bore size, Piston/wrist pin fit in connecting rod and piston Corrected lifter bore angles and clearances(probably entail bushing the lifter bores) Align hone the main journal bores Check and adjust bearing tolerances equally as desired Torque plate hone the cylinder bores to piston tolerance/fit File fit piston rings Fit/check piston rings to ring lands for proper tolerance/clearance (may require custom rings) Mill the block deck to correct compression height. And 3/8 pushrods may require clearancing/grinding the cylinder head pushrod holes. This will be a good start. Anyone else wish to chime in were my old brain has missed something. |
looks like you have covered it all.
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Have them check camshaft bearing alignment, RB's can have problems in this area.
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Originally Posted by Coronet 500
(Post 143085)
Have them check camshaft bearing alignment, RB's can have problems in this area.
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Originally Posted by Iowan
(Post 143080)
I think .030 over 4.15 stroke is only 495 Bob.
The car is going to be street driven only so must remain smooth and civilized, use oil like a modern car (if possible..,) and be bombproof enough not to need rebuilding for decades! :) |
Hey guys, Thanks for all your very helpful input! I spent this weekend stripping the engine to a bare block, quite illuminating! Internals seem to be in good nick considering I found nearly an inch of semi solid grey oily sludge in the sump..... Major ball-ache was that I managed to knock both rearmost freeze plugs into the block, derr... Had a rummage around with a coathanger but unable to get at them, will have another go with a small magnet. And it was all going so smoothly..... |
Having got the stray freeze plugs out surprisingly easily, I have started gathering parts for the build based on 4.150 stroke, but an anomaly has cropped up that I hoped you guys could advise on.
It has to do with the rod length. Those I've ordered are 6.760 long but I see in my Mopar book that the originals were 6.768 long, and I failed to notice that the piston specs are based on the longer length so presumably all my calculations of compression, rod ratio etc. are going to be way out aren't they? Or is the difference negligible? I am using 78cc Trickflow heads, the other components as detailed below: Molnar DH6760VTB8-A rods http://www.molnartechnologies.com/ro...-chrysler.html Molnar 440-4150MC6F crank http://www.molnartechnologies.com/cr...-chrysler.html SRP 321521 pistons with S100S8-4350-5 ring set http://www.jepistons.com/Products/231521.aspx Thanks in advance for any input! |
You can make up the .008 in the machine work.. :)
Compression might be a little higher than what you originally was looking for... So far so good.. |
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