408 stroker vs 383 stroker?

[brickyard69]

I am at the point in my project (69 Camaro) where I am ready for my motor.

I have a Muncie 4 speed and a 373 rear. The car will be used 90% on the street. No vacume accessories and I want a real nice thump at idle.

I was planning on building my own 383 until I ran across T&L engines. http://cgi.ebay.com/ebaymotors/408-C...mZ300000903481

I never thought about a 408.

What are your opinions on a 408?

It looks like it is still a 350 block (4.030) but with a 4.00" stroke vs 3.75". Is that correct?

Steve

[jeffs68]

Well I'm not sure which engine you will like better but a 383 sbc is a 350 block with a 4.00'' crank out of a 400 sbc.This 408 is just a 400 that has been bored to rebuild it.The 400 does have a little bit different set up than a 350 as far as needing holes drilled in the heads for the steam passages on the block but its not a big deal.Just beware I purchased any engine on ebay once and it was junk even though the guy had a great rating and I talked to him before hand.

[ProdigyCustoms]

The stroke on a 400SBC is 3.75 which makes a 383. I did not look to see how they are making 408, but if you are starting from scratch, a bigger bore 400 based block will kick the doo doo out of a smaller bore 350 block based motor. there is no substitute for the advantages of valve unshrouding that comes with the bigger bore size.

[jeffs68]

I apologize I guess I was given bad info on a 400 crank if thats the case than your right where are they getting 408 from.

[rocketman]

I build engine's and I dont like 383's.If you want a stroker I would build a 396,or go to the 400 style and build a 406 or go 427 or 434.

You can make any engine thump,it's all in the cam,I can make a 355 sound like a 427.

[WS6]

destroke a 400 and rev the snot out of it. 377s are cool little motors.

Rocketman why don't you like 383s? Given the ability to feed a 396 with good heads I would choose that for a stroked 350 as well. However, you can do so well with a simple 383 without having a large investment in the correct heads needed to feed a 396. Just curious to your reasons and insight.

Steve, it appears that they are using a 350 block. Personally, I do not like their ad. They may build perfectly good engines and that engine itself may be perfectly good. However, they don't say what the bore size is and they leave off other dimensions I would consider critical and should be listed with any engine build. Also, look at their list of parts used. They have some nice parts listed, but they only mention some of the suppliers like ARP. They should be listing every manufacturer used. The double roller they use sounds good unless its a cheap chinese knock off and they are just afriad to tell you. So personally I don't like the ad. It just doesn't sit well with me. Like I said though, it may be perfectly good.

[rocketman]

WS6,I just think a 383 is not worth the money, if you build a 5.7 rod 383 they have good bottom end but have no top,a 6 inch rod has a good top end and no bottom,5.585 rod is a turd.

Yeah there's a ton of 383's out there,I just don't like them.Anybody that comes to me for one I lead to 396.For the money the power a 396 make's I feel is money well spent.

[SStrokerAce]

I don't see how rod length has **** to do with it. The extra grinding on the block and the more expensive crank along with the rod/cam issues/comprimises makes a 396 a PITA.

A sidebar in Chevy High Performance magazine, by Darin Morgan, Reher-Morrison's R&D cylinder head specialist.

Quote:
Rod Length

Most people tend to overgeneralize this issue. It would be more accurate to compare different rod-to-stroke ratios, and from a mathematical stand-point, a couple thousandths of an inch of rod length doesn't really change things a lot in an engine. We've conducted tests for GM on NASCAR engine where we varied rod ratio from 1.48- to 1.85:1. In the test, mean piston speeds were in the 4,500-4,800 feet-per-second range, and we took painstaking measures to minimize variables.

The result was zero difference in average power and a zero difference in the shape of the horsepower curves. However, I'm not going to say there's absolutley nothing to rod ratio, and there are some pitfalls in going above and below a certain point. At anything below 1.55:1 ratio, rod angularity is such that it will increase side loading of the piston, increase piston rock, and increase skirt load. So while you can cave in skirts on a high-end engine and shorten its life, it won't change the actual power it makes.

Above 1.80- or 1.85:1, you can run into an induction lag situation where there's so little piston movement at TDC that you have to advance the cam or decrease the cross-sectional area of you induction package to increase velocity.

Where people get into trouble is when they get a magical rod ratio in their head and screw up the entire engine design trying to achieve it. The rod ratio is pretty simple. Take whatever stroke you have, then put the wrist pin as high as you can without getting into the oil ring. Whatever connects the two is your rod length.

Bret

[rocketman]

Maybe the rod length thing is my imagination.But in a race motor I have seen the results on a dyno.

I have only built a couple stock block 396 those where all lt-1's,all my other's are all dart blocks.

We try not build 396's on stock blocks like Bret said to much grinding.

I don't want start a 383 post thats 20 pages long so I will just leave at I personally don't like them.Maybe I should build for the hell of it and see what I get out,maybe it was just my building style then.


Brickyard 69,good luck with what ever you buy.I will say this T&L is one of the best engine builders in Charlotte.Call them up they don't build any junk.

Rocketman

[ProdigyCustoms]

In my opinion, if someone owns a 350 block that is a good block, and wants to build a better motor then a 350, a 383 dollar for dollar is about equal and will usually out perform a equal 350. however, if starting from sctrach, without a block, a 400 based motor is a much better choice.

As for the 396. If you have a LT1, you are limited to the block, so be it. But to build a 396 from a 350 block? not my first choice. Not my second or 3rd choice either.

But hey, that is juts my opinion, and you know what they say.

[SStrokerAce]

I agree only place that I'll do a 396 is in a LT, hell have one in the shop now.

I usually go as long as I can on the rod length and tighten up the ring packs on about anything I do. A 6" rod 383 with the right pistons isin't going to be any trouble at all, except if you are spraying the snot out of it OR blowing it. Then you just need a beefy piston in there.

I do really like 383's though, if you match teh cam and heads up they are killer inexpensive motors.

Bret