Speed-o-motive of West Covina, CA (www.speedomotive.com). They advertise in Super Chevy all the time, offer what appear to be pretty good deals on SBC 383s. I have spoken to them, and they sound okay, I was just wanting to talk to someone who maybe has used their engines. Anyone???


[Modified by frodo84, 3:23 PM 10/4/2001]

 

I have heard some negative comments with this company but not so much on this forum.

I personnally cancelled a 406 short block because they continued to extend the delivery date.

Seem to have good prices though so may be worth the time...

Good Luck.

 

Thanks for the input, that's just the kind of stuff I want to know, if they are reliable, etc. is the product of high quality? I talked to a real nice guy on thirdgen, he is running a short block from there, seems happy with it.....

 

There are several guys over in the C3 section that have used Speedomotive, the consensus is pretty negative. Alot of accusations of parts substitution ( a cast crank when a forged one was paid for), continued delays, poor after-the-sale customer service, shoddy workmanship, etc. They onbviously do alot of work, and the complaints mentioned are probably a very small percentage of all the work they do, but the thing that would disuade me from doing business with them is their poor customer service.

 

SOM used to be well-known and highly respected. However, over the past year or so, I've heard nothing but bad things and horror stories about them.

 

I have two motors with parts from them 383 & 393. They are just one of many vendors. The best thing to do is search the internet. In an old post I had listed a site that had everything in the way of stroker chevy cranks.

IMO - buy only internally balanced and don't stop at 383 use a 3.875. the cost is the same.

I should add that I didn't have a problem and I recieved a better crank than I ordered. When I call them because I had to send something back he said "no problem, they must not have had what you wanted on the shelf. So i got the $200 nitride job or what ever it costs for free job for free.



[Modified by gkull, 1:30 PM 10/9/2001]

 

Again, thanks for the input from all. gkull, you said "don't stop at 383", can you expand on that? I am trying to gather data, and am thinking that the smart move would be to build based on a Motown block, which can go to 427. I'm somewhat concerned about rod length (ratio), and loading on the rods. I mean, by the time I pay for a chevy block and do all the things to it to insure a strong bottom end, could I have paid for a Motown and gone further (cubic inches) for about the same money? Is that what you were getting at? For what it's worth, I spoke with someone at SOM and they would gladly build an engine based on either block, just more money.....anyone running a Motown based engine?

 

My experiences with Speed-o-motive:
1)The engine took way longer than they said to build, but I was still waiting on other parts anyway.
2)The price was great. (especially on the AFR190 heads)
3)I didnt specify that I needed the additional sensor locations, etc. on the heads or the egr passage, but did tell them they were going in an 88 corvette. They took them back off, sent them to AFR for the additional machining, and re-installed them. All I paid was the machining costs from AFR, so I was very happy with their service.

 

I am pretty happy with my SBC 427,and would recommend it to most people.

I used the GM Rocket/Dart Iron Eagle block as the basis for my engine. I used a tall 9.325" deck block specifically for the rod/stroke ratio benefits. With a 4.00" stroke, you'll never achieve an optimum rod/stroke ratio, but you should strive to maximize it if practical. There's great debate as to whether or not a better rod/stroke ratio affect overall power, but it does affect side thrust loading, piston/cylinder wall/ring wear, and rpm acceleration. The increase in side thrust loading contributes to increased internal friction, thus costing power.

I would recommend the Dart Iron Eagle/GM Rocket block over the Motown,but the Motown is a very good blcok. I recently helped a friend build another SBC 427 based off of a Motown block. He ended up amking 608hp/598tq with a pair of AFR 227 heads and a Victor JR intake.

There is no comparison between a production block and an aftermarket block like the Motown or Dart Iron Eagle/GM Rocket. The aftermarket blocks are designed with stroking/boring in mind. Everything is thicker an more heavy duty.

 

Monty,

I am very impressed with your website and engine, thanks for the information. What do you think about the min/max of the induction system (cfm) for an engine exceeding 396 c.i.? I am struggling with decisions about what I can put under the hood of my '84 and feed a new engine (383, 396, 427). I want to retain stock appearance, and even retain TBI if possible, but I am unsure if I can if the engine goes over 400 c.i. Obviously, you are way out there in terms of hp and torque, I am thinking about a 396+ stroker with a full roller and alum heads. I am currently using a '7747 ecm, so prom tuning is not a problem as long as I stay TBI, but if TBI won't cut it I will go another direction. Thanks again for any and all comments.....

 

I modified my Crossfire TBI system before I converted over to Accel DFI and now SpeedPro SEFI, but I'm not too sure it would flow enough to support a stroker motor like you're talking. You really need to get your intake flow over 300cfm per runner, and the Crossfire manifold will not flow that, I don't think. I know porting it and opening up the port exit to match the head runner helps alot, and there has been good results seen from Extrude Porting it, but I still don't think you'll get it to flow enough. I could be wrong though, you might want to give Turbo City a call, they can probably give you some good advice.

I would be a shame to spend the money on a nice new stroker motor and good heads and then choke it with an intake that won't flow more than 220cfm per runner.

Otherwise, anything that will fit under the other C4's should fit in your '84. An EFI converted single plane manifold would probably be the easiest, and least expensive EFI solution that would support the ci's and power you're looking for.

 

What I was saying about stroke to 3.875. The price of a forged crank, 6 inch bushed rods, and JE pistons that go with it is all the same price for all of the following strokes 3.750,3.800,3.835,3.875

The amount of block grinding difference would be marginal. So why not go with the more cubes. The 3.875 is how they make 396 ci out of 4.00 based motors and 415 ci out of 4.125 based motors.

I just don't want to see anyone make the same mistake as me. I was in a hurry and didn't fully map out my long term goals.

 

gkull, that's exactly the kind of info I am looking for...thanks very much for your insight to this. I want to be sure about where I am going before I start putting parts together.

Monty, thanks for the input. I am going with my x-ram intake now, which as you know is a Weiand x-celerator modified to accept the dual TBs from the original engine. I am running 2" bored TBs now, they should flow around 650-675 cfm. Is that enough for a stroked motor? That's what I am trying to figure out. I think the x-ram will support the stroker, I am only concerned about the TBs. I was thinking that I could use a TB from a 454, but I don't think it will flow any more than my two bored TBs do now. By staying TBI, I don't have to go to an aftermarket ECM and can run my '7747, saving the money to put into better motor parts. What do you think about that as a plan? Thanks in advance for all the good advice guys!

 

If they flow 600+cfm each, you should be fine. My motor runs through a single 1300cfm monobade throttlebody.

Still, I think you would be best served by uilding your motor with low to mid rpm torque in mind. Even on a 350, the TBI manifolds are not known for high rpm operation. On larger motor the rpm rnage is further reduced. If you select your cam and heads with a 6000rpm limit, you'll probably be fine. It's hard to say for sure, because I'm not aware of anyone trying to run that type of intake on a large stroker motor. You'll definitely be pioneering the way.

 

I completely agree about the low and mid rpm torque comment. About my existing TBs, I think they flow around 675 together, not each. I am looking at either using 454 TBs, or going to an EFI converted manifold whichever will get me the airflow I need. I suspect the EFI converted manifold is a better overall choice, it just costs more $$$. Oh, well, it's only money right? And it's still cheaper than a new C5.......

 

Well, I can't speak for every engine that SOM builds, but here is a sampler of items on a 406 short block that they sent me for one of my other cars:
1) Block was not hot tanked prior to work, there were several layers of thick paint on the block from prior builds.
2) They did not chase the cylinder head bolt holes, or any other bolt hole for that matter - the threads of these bolt holes were still full of all sorts of junk! There is not any chance at all that a torque plate was used during cylinder boring - they said that it is not required to use all the cylinder head bolts on a torque plate !?!
3) Block was not decked on this build, not even a clean up decking - they said it was still straight enough that no decking would be needed.
4) I paid for ceramic coated piston tops. One of the pistons mysteriously had the ceramic coating sanded off - their response: "ceramic coating does not really do anything" (contrary to even their own web site).

Draw your own conclusions. The engine actually runs decently, not as well balanced as it should be. a cylinder leak down test showed good results: 4% to 6% on all cylinders. My chassis dyno results showed weird results: 614 ft lb torque at 3,200 rpm at the rear wheels (3,000 rpm stall converter), and it flatlined at ~ 339 rear wheel hp from ~ 4,500 rpm to 6,200 rpm (where I shut the dyno runs off at)

Since I will be replacing the Milodon kick out oil pan (I dented it on engine installation into the car, that dent later turned into a very leaky crack. It will be very interesting to see what I find when I remove the oil pan (it was already installed when I received the engine). If I find that the splayed main caps that I paid for were not installed, then I will have to see what they say about that!

Thomas

 

Thanks very much for relating your experience, please don't hesitate to post or email me when you remove the pan. Regardless of the builder, what you related sounds pretty shoddy.....

 

Off the thread,and you may already know this but no matter what modifications you make on your '84,take a good look at the fuel lines.I had to change mine to get the flow rate required when I installed my LT4.The '84 has an extremely small return,which backpressures the system if not replaced with the larger diameter line.I replaced mine with '96 parts.In replacement,I found the existing lines had various flat spots and scrub areas(119,000 mi.) which would have restricted flow and ,in my case with the new higher pressure pump,become dangerous if the line scrubbed enough metal off to rupture.BTW,changing them is a miserable job!!! :nopity
Note, also, that the Fuel Tank Cover Assembly also needs to be changed due to the smaller diameter line.


[Modified by ET, 1:32 PM 10/16/2001]

 

thanks, ET I did not know that. I am getting a lot of good info from this thread!!