Hello,

Does anyone have any experiance with this assembly...
http://www.sdpc2000.com/catalog/450/...g-Assembly.htm

It appears to be a pretty good price for what is included. Any help would be appreciated.

Thanks,
Jeff

 

Doesn't sound bad at all. Scat makes good stuff.

 

Looks OK to me, all you really need for street/strip

 

A 406 is nothing more than a stock 400 with a .030" overbore. Did you buy a bare block? Do you NEED all this? I would think you could piece this together, buying only what you need, of similar quality, for less. I don't see anything wrong with it, though.

RACE ON!!!

 

You could use stock parts to build a 406ci but nobody does, stock 400ci Gen 1 rods are 5.65 in. and are not used in any HP buildups I have seen. The kit above comes with 5.7in. and the pistons to go with that rod length so you couldn't use stock pistons either.

 

I looked at the link, but I missed the 5.7 rod listing. Actually, if you were correct, I wouldn't sweat over a rod length difference of .050". The fact of the matter is, that the stock 400 rods are 5.565". Decent rods can be had for $100.00 to $150.00, and that crank isn't a lot better than stock. In any case, I never expected that he might reuse his pistons, rings or bearings.

AND, as I said, there is nothing really wrong with the linked package, except maybe the price. Oh yeah, and the high volume oil pump.

RACE ON!!!

 

Thanks for the information so far.

Stock 1972 block...4 bolt mains...#3951511...shaved 0.005"...4.155".
Stock crank...turned 10/10.
Stock rods...5.565"...also 10/10.
Speed Pro Pistons...H400P...+.030"...0.020" in the hole.
Sportsman II cylinder heads...steel 64cc straight plug.
Porting work done by performance shop...now 68cc.
Crane hydraulic cam...#110691...238/244 @ 0.050" and .502/.516" with 1.5 roller rockers.

Best et with current combo is 11.88 @ 116.12 mph.

Looking for more power/strength in the lower end. I bought the Vette with this engine in it. It was built by a local performance shop, but I wanted to check things out for myself, and had no paperwork on it.

This is my first performance SBC engine. My last 25 years has been dealing with Big Block Mopars. I have been doing quite abit of homework on SBC engines.

According to David Vizard's book, "How To Build Max Performance Chevy Small Blocks On A Budget" he states "NEVER use the 400 5.565" rod on any SBC, especially if it is a 383 or 400 package".
He also seems to favor the Scat crank with Scat I beam rods for performance on a budget.

Most of my research shows that I should be using either the 5.7" or 6" rods. Is this correct?

If I was really tight on cash I could use the stock crank/rods/pistons and just re-ring it and throw in some new bearings. I guess I'm just at the "while I'm at it phase" in Corvette ownership.

Let me know what you would do with a budget of about $1500.00 for parts alone.



Thanks,
Jeff

 

I found a vendor on e-bay that lists the main parts individually.

Scat 9000 crank---$189.99 http://cgi.ebay.com/ebaymotors/ws/eB...category=33616

Scat I beam rods---$179.99
http://cgi.ebay.com/ebaymotors/ws/eB...category=33623

Sealed Power pistons that would give me right at 9.8-1 compression.---$179.99
http://cgi.ebay.com/ebaymotors/ws/eB...category=33623

What do you all think about going this route? Then I still have to buy my bearings, rings, gaskets, frost plugs.

Thanks,
Jeff

 

I think the package you have will be fine.


I built my 406 using the stock 400 crank ($150), 5.7 Eagle I-beam rods($200) and TRW Hyperutectic pistons ($200)

David Vizard say you can use the stock crank up to @ 450-HP but I dont thrash mine a lot and mine has been ok thus far.

 

First, as I've said all along, there is nothing wrong with the kit. I like this approach better. Why the crank? From what I've read, I don't see any advantage to that crank, over what you have. The rods look fine. Just be sure to ask if they will clear the cam with a 3.75" stroke. I am VERY curious about your piston choice. You would be trading flat tops for a 12.5 cc dish. Do you really want to lower your compression ratio by 3/4s of a point?

Two items have caught my eye. Both concern the block. Is that a factory, 4 bolt block? Or has it been converted with 4 bolt, splayed, main caps? The factory, 4 bolt block is a lot weaker than the 2 bolt block. You may be OK, but it is something to be aware of. My other point of concern is the generous, .020" deck height. You will get better, more efficient, combustion, plus detonation resistance with a much tighter piston to head (squish) clearance. Of course the head gasket you use is important, but I would shoot for a .035" to .040" piston to head clearance.

RACE ON!!!

 

Thanks for the input...

I was under the impression from reading Vizard's book that the Scat crank would be stronger than my stock crank. I'm not looking to throw money away...but I want to increase reliability if possible within my self imposed budget.

The block is a factory 4 bolt main block. I have noticed that many say the 4 bolt main block is not as strong...figures.

My thought on the pistons was to try and get close to 10.1-1 compression. I thought the appx. 10.6-1 was a little high for the street using steel heads.

What do you think of having the block brought down to 9" even for a zero deck, using the Scat 5.7" rods attatched to my stock crank? I want to keep the engine external balance mainly because it has a new balancer and flexplate. What pistons would you recommend?

My cam timing at 0.050:

intake
opens 17* BTDC / closes 41* ABDC / max lift 102* ATDC
exhaust
opens 52* BBDC / closes 12* ATDC / max lift 110* BTDC

The LSA is 106 degrees...installed straight up.

I don't have a problem with having to run 92 octane...can this be done with this cam, zero deck block, 5.7" rods, and flat top pistons?

Thanks,
Jeff

 

In my opinion, a Chinese cast crank isn't likely to be enough stronger than the stock, nodular iron, Chevy crank, to justify spending an extra $190.00. Especially to put in a limited strength block. I wouldn't say that if you were considering a forged crank.

I did a little figuring for you. If you go to a zero deck, you have selected an appropriate piston. Using a gasket with a 4.190 bore x .041" thick, you end up with a 10.7:1 compression ratio. If you feel that is too high, 2 ccs per cylinder of valve unshrouding, in other words a 66 cc combustion chamber, knocks this down to 10.50:1. With 68 ccs, you get down to 10.25:1. You are MUCH better off altering the compression ratio with the head or piston volume, than with the gasket thickness.

I think this saves you some substantial money AND boosts the power. I am trying to understand the usage and help lower the expense. I don't think this makes any compromise over your initial plan. How about the rest of the Forum? Any thoughts?

RACE ON!!!

 

CFI-EFI...


Thanks for the info.

My Sportsman II's have been worked over already. They are at 68cc's which would put me at the 10.25-1 with a zero deck according to your posting...I think this would work great. I would probably shoot for a set of gaskets that would compress to a 0.039" giving me a "good" quench area.

The Vette is driven pretty much everyday from April 15th- Oct. 15th. I also want to run it a few times at the track when possible. I don't have to count on it as I have a newer truck that I can and do use when the Vette is unavailable.

I'll have to keep my eyes open for a 2 bolt 400 block for future builds. I always thought 4 bolt mains were a good thing...until I read up on the 400 blocks.

Thanks,
Jeff

 

I thought I had read above that you had 64 cc heads. With 68 ccs, this works out very well, in my opinion. The .002" thinner gasket is even better for quench and shouldn't affect the compression much at all. Good move.

Chevy made two different types of 4 bolt blocks. The 4" bore blocks ARE stronger. For some unexplained reason, they didn't carry that over to the 4 1/8th" blocks. I have a block, but I can't imagine it's worth shipping. Just keep looking. If you're not in a hurry, one will turn up. A "block" I bought before the one I have now, I paid $150.00 for, and drove it home. It was a decent running Caprice. It had the 2 bolt 400 and a TH400 trans.

RACE ON!!!

 

I run a 511 casting block and have turned 6500 rpms many a time with no issue. I baught it bare, and HAD to purchase a rotating assembly. I went with a SCAT 9000 kit,and the whole assembly was balanced. This is the main reason I'd recommend a kit. In order to achieve a good balance,all part weights are concidered. You buy one piece here, and another there,there's now way to know if it will end up in balance,unless you pay to have it balanced also. The cost of that may offset what you saved by buying the parts seperate.
Since you already have a running 406,and a budget of $1500,I'd scrap the iron heads,and pick up a set of AFR 195's or Victor heads. The aluminum will save some weight,and will allow pump gas with 10:1 easy.Increased power through the entire rpm range.

 

I knew that the heads were 64cc when new. I just CC'd them yesterday so I would have accurate information when trying to determine compression.

I'll talk to my machine shop Monday and get his pricing on decking the block and see what it would cost for him to balance my assembly of parts. I have know him for years so I usually get a pretty good price and quick turn-around.

I'm also going to check with some of my contacts to see if anyone has an extra 400 laying around.

Thanks again,
Jeff

 

I have heard of people having good results using this block. I too thought of going with the kit to take the guess work out of the assembly.
I sent SDPC an e-mail asking what it would take to swap to the piston's that I need instead of the ones in the package, and to swap the intake gasket and exhaust gasket to work with the larger ports in my Sportsmans. I sent it on Wed. and have still not heard back from them as of today.

Thanks,
Jeff

 

Vetdrms has a Scat 9000 crank and has shifted his 406ci at the dragstrip at 7000RPM's, the crank is probably the best crank you can get for the money

 

I hope I wasn't misunderstood. I wasn't speaking out against the Scat crank. I agree they are great piece for the money. I just don't see that there is much to be gain over what he already has.

I have made no mention of balancing, but yes, it will absolutely have to be balanced. The "kit" comes balanced, but like everything else in the kit, it does have a cost, even if you can't identify exactly what it is.

If he should go to aluminum heads, he may be able to use the pistons in the kit. With the "kit" pistons, a .039" gasket, 68 cc chambers, and a zero deck, he winds up a 11.00:1 compression, which doesn't seem out of line with his cam and the aluminum heads. Here we go... Spending his money!

RACE ON!!!

 

Iwould use the 4 bolt block no problems for street and occasinal strip use I don't see any problems, these blocks have become very popular in certain circle track racing and in that case where you on it for an hour or so I would chose a 2 bolt and possibly have that converted to splayed 4 bolt. Alot of this stuff is overkill for street/strip motors in my opinion. The same goes for forged stuff like cranks, not really necessary unless it is a dedicated race car. A good cast crank will hold up for many 1/4 miles passes in the 10 -13 sec. range.