Converter and Cam Question

[TexasRed]

Just a little update, I've got the block back from the machine shop. You know the phrase, measure twice, cut once? Well, what I thought were factory standard pistons (everything else looked factory) turned out to be .040 over already. . . so my .030 pistons were gonna have to run a lot of clearance.  .
So they sold me a 2-bolt core that I could use. Then a day later they tell me my stuff is ready but I gotta pick it up today, they're closing the shop that day. They did what they call a "Vat Special"- cleaned, checked for cracks, bored, cleaned the deck, installed cam bearings, freeze plugs. Do I need to clean the bores for any grit? I think not cleaning a motorcycle block after boring messed up some rings one time.

If I use that Isky cam do I need to use an oil pump over stock? That 270 looks almost like a little too much for the gear I'm running. I think I'll run the beehive springs if it gets me a little less cam wear in the future and allows a lot easier revving. Now if I could only get paydays closer together.

[modular93fox]

why not get a custom built converter they cost as much as an off the shelf unit but are exactly made to fit your cam. i sent my friend down to a shop down in houston (who does grave diggers converters) and costed about 250- 300 (4l60e) for a converter built for his car (lbs) and cam. you cant buy that off the shelf. it runs great and his original converter was back in his car within 24hours.
clint

[VileZambonie]

I can get performance converters for cheaper than that. There's not much too them.

Clean the engine again yourself. As the builder it's your responsibility to check all of their work. Wipe the cylinders clean and apply a fresh coat of conventional 10w30 to the cylinder walls. Soak the pistons once the rings are on in a container in the oil also.

[eventhorizon66]

If I use that Isky cam do I need to use an oil pump over stock? That 270 looks almost like a little too much for the gear I'm running. I think I'll run the beehive springs if it gets me a little less cam wear in the future and allows a lot easier revving. Now if I could only get paydays closer together.

Now don't think that I am advocating a "fancy parts fix-all" with those beehives.  They represent a significant investment and I would buy a retainer and checking spring first to verify they clear the valveguides at the lift you want to run.  Remember the article I posted was testing the #26915 and #26918 springs.  The one I'd use for a flat tappet cam is a #26986.  Another thing that concerns me is the bottom OD of the two springs in the article is 1.29" whereas the bottom OD for the #26986 is 1.412".  This may mean it will still be necessary to machine the valvespring pockets larger with this spring.  Check you spring pockets' diameter before ordering.  Also, the "potential" for decreased cam wear comes from setting them up with less pressure than a typical spring.

For example: the valvesprings that Isky recommends for its 270 Megacam will have 115 lbs at an installed height of 1.7" and approximately 259 lbs at .465" valve lift.  The #26986 beehive spring will yield 123 lbs at an installed height of 1.75" and 253 lbs at .465" valve lift.  This isn't a significant enough difference to justify the increased cost.  But when you set the #26986 to an installed height of 1.78" the seat pressure drops to approx. 115 lbs (like the Isky recommended spring) and the pressure at max valve lift of .465" drops to 245 lbs.  And this decrease of 14 lbs (over the Isky spring) at max valve lift can result in dramatically decreased cam wear over the long haul and less chance of break in issues.  But is this worth the extra $100 to you?  When you add in the fact that they might just drop in without machining the valveguides, yes would be a perfectly resonable answer.  But at this point it should be clear that you should also check your maximum available spring installed height on your heads (dependent upon the depth of the spring pockets and the length of the valve stem).  Machining may be required, making this spring less of a sweet deal.

Here is a pic that illustrates one of the reasons why beehive springs have superior capabilities over traditional springs.  The spring/retainer pair weighs a heck of a lot less.

Source: http://www.popularhotrodding.com/tech/0607phr_camshaft_basics/index.html

Also there is no reason why your choice of cam would have any bearing on your choice of oil pump.  The cam lobes' lubrication comes from oil spash off of the crank and what oil falls on it on the way back to the oil pan.  So the cam doesn't see the difference between 5 psi or 65 psi.  Your bearings are another story, but high volume oil pumps rob power, can suck a stock pan dry, and are probably overkill in most cases.  If I were building an engine from scratch, I'd buy a stock replacement Melling pump, disassemble it, and blueprint it (check/correct all clearances and relieve/smooth all passages).

If you are concerned about the cam being too large, it is always better to err on the side of too little cam than too much cam.  Read the article I posted above to become more comfortable with selecting a cam.

Keep us posted.

[TexasRed]

I'm still working on 'er. I started cleaning the bores, but it's taking forever with purple power, hot water, and a scotch bright pad. I guess I'm supposed to do this with dishwashing soap and lots of hot water? Anybody have any tips on making this easier. Don't want to spend 4 hours trying to get grit outta the bores.