chevy 250 build and 200 hp ??

So…. I am picking up a chevy 230-250 out of a 1970 Nova on the cheap!!! which still runs. I have read every thread on the 250 here on the Hamb. still have a few questions and make sure im on the right path to 200hp, as this is my first build. It will be going in a '54 chevy 210 that I will be picking up next weekend (already paid for). There is no engine or trans in the car now so it will need something.

<O</OI will be picking up all the goodies from Langdons, carbs, intake, headers, motor mounts, the works!

<O</OMy main question is which, pistons, cam, crank, rebuild kit do i need to hit 200 hp?

<O</OWhat else needs to happen to hit 200hp as far as head work?
I have read about the lump port heads, is this a must?
Do I need to buy a new head already done? or machine the head it comes with as long as its not cracked or nothing screwy..

Also how do I tell if the crank that is in there now is the 230 or 250? <O</O
Is this the only difference between the 230 and the 250?
<O</O
Trans is probably going to be the T5 with S10 axle (non posi).<O</O
<O</O
CLIFFS NOTES: getting a 230-250 engine guy says 250 but not sure. what do I need to do to hit 200hp. Thanks in advance John. <O</O
<O</O
Oh and if anyone wants to help me re***emble the engine when I get all the goodies the more the merrier, I am still learning and could use a dozen mentors. Could be a Hamb Party in my garage FREE BEER!!! and Bone Daddys BBQ!!! and If you have been to Bone Daddys you know this is a great deal!!!

 

Flattop pistons from a V8 to replace the factory dished units and raise compression (283 pistons if it's a 230, 307 pistons if it's a 250) Same bore, but 230 has 3.25 stroke as opposed to 3.53 for 250. Clifford or Offenhauser 4 bbl intake and smallish carb (Holley 8007 or 400 cfm AFB), tubing headers are available new (expensive) or used (much cheaper) from several manufacturers in both long and short tube styles. An H.E.I. distributor with a recurve kit will do anything you need it to do. There are a couple performance hydraulic grinds out there for cheap. Don't make the mistake of mixing up 6 and V8 rocker arms, as the sbc rockers are 1.5 and the 6 rockers are 1.75.

 

Call Tom Langdon. He is the guru of these motors. Also check out inliners.org Todd

 

Carefull on teh beer ***embly. We spent two days ***embling the engine for my 54. After teh first 2 cases we had decided that we better stick to the beer at that point, left the timing gears off and ****oned it up. Funny how those rockers dont move w/o that vital link!?

 

Heathen: so i need flat top pistons. how do i know which crank in the there? what do i measure when i pull it out? i guess the guys a the machine shop could tell me?
which HEI do i need are they pretty much the same? did a google search they can be had for 100 of less so thats on the list.

Tugmaster: yeah I plan on calling langdon.

Tman: Beer party is for when the engine is complete!!! once i have all the parts and machine work done, it shouldnt take more than a few hours to ***emble.. I would think. Could be wrong though..

can anyone recommend a rebuild kit? and if i have the 230 crank does anyone know where i can get a 250? thanks John

 

Find the cylinder head off of a 194 CID six, casting number 3864883. Mill it .060, and with the already smaller combustion chambers, it'll bring the CR up to 10:1/10.5:1 on a stock 250. Mild cam, small 4 barrel or larger 2 barrel carb, headers, OR, turbocharge it, and don't worry what the CR starts out with, or having to do a lot of head modification. HEI is a must compared to the points distributor with the breaker plate held in position by a spring! Butch/56sedandelivery.

 

56sedandelivery: thanks for the info. i will be looking for that head! i read that someother place thanks again.
I agree Hei is a must.

by mild cam what should i be looking for? if anyone can post a link that would be great.

also if someone can help me pick out a rebuild kit that would help too! again this is my first rebuild. everything ive learned i have learned from you guys. thanks again john

 

tlowe here on the hamb has done a ton of dyno tests with various combos of intake, exhaust, cam, ignition etc. he also came up with a set of lumps for the head. PM him - he will get you a kit for exactly what you want.

 

6inarow: thanks i will send him a pm.. thanks

 

An option for ignition is a Pertronix kit in the stock disti housing. I love the HEI in my 292, but it's ugly.

Side question: what's the deal with 200 horsepower? We know it's going in your 54, and it'll have a manual...but what's your intent? Mild cruiser? Stoplight drag car? These inlines have specific strengths and weaknesses, and while you've maybe already thought about it, I'd hate for us to lead you down a wrong path.

 

63biscuit: 200hp because I wanted to throw a number out there that was obtainable without breaking the bank and have enough power to get out of my own way. The car is going to be low mild cruiser. I'm not oppose to more horsepower but i am not going to be racing the car. If I can get up and down the freeway at 75plus mph I will be happy!!!.. By the way Texas speed limits are going up to 85mph in some areas, so maybe I'll need more Hp... John

 

Can anyone recommend a cam and rebuild kit? Well I have read that 2wd axle from s10 is to wide and that I need the 4wd version.. Does it matter which year? Thanks John

 

I ran a stock 250 in my 50 Chevy. I was using a TH350 with a 94 S10 4x4
rear with 3.42 gears. If I had to do it all over again I would either go with 3.08 gears or a OD trans. All in all it had PLENTY of power. Like I said talk to Tom Langdon. From the little bit of research I did do, the achilies heel of the 250 is the head and cam. Lump ported heads, a header and a mild cam really makes a huge difference. Here's a link for ya!! Todd

http://www.12bolt.com/250292_inline_products/bolt_in_lump_kits

 

Yes I will be getting the head from Tom ... A little steep for my budget but seems like it's worth it..

Found this trans I'm gonna pick up already rebuilt just want to confirm this is the one I need. S10 T5 NWC 13-52-145 with a mechanical speedo. Out of a GM 1985-86 S-Truck 2.5 L4-2.8 V6. Thanks for all your help I really appreciate it. JOHN

 

Great stuff, I'm in the same boat, 200hp +/- driver with an I6. Inline Chevy Power Manual
http://www.amazon.com/Chevrolet-Inline-Six-Cylinder-Power-Manual/dp/1931128154
is also a great read, goes over everything, Tom is mentioned in there with a lot of other guys who know their stuff.

 

Ok quick question on the trans. If I buy the trans I have been looking at it's the trans only. Now bell housing no clutch nothing else. Would it be better to buy a complete trans and bell housing or does it not really matter. There are easy to come across.??

 

One of the good things about Chevy engines is the interchangability. 250, small block, big block, even 348/409.....flywheels and bell housings interchange. I don't even know how many of each I've got in my garage. They are still dropping out of trees. The only special pieces are the externally balanced flywheels for sbc 400s and bbc 454s.

 

Thanks for the help. I have the original 235 that came out of the 54 with trans .. Will that bell housing work with a t5 trans and 250 L6?

 

no....

 

only a new guy would dare offer free beer................nice jesture though

 

I did a complete break down of the engine.. it is a 230 not a 250 as advertised.... question where should i pick up a chevy 250 crank. i am going to pick up the chevy 250 rebuild kit from clifford along with a clifford cam. What crank do i use... i tried google but came up with nothing.

i also pick up a completely rebuilt trans from an 85 s10 NWC 13-52-145.. just need to find a bell housing and cluch ***embly.

 

Why not let your machine shop buy the parts, you will get better service if they supply the whole package. Clifford's won't be any better then a good Felpro set or Sealed Power, and I bet a lot more money.

Don't get carried away on a big camshaft, you can kill the torque real easy. Use one of the universal replacements cams from TRW or Sealed Power, you will get a good idle and plenty of low rpm power. With overdrive, you will need all the torque you can get at 1800 to 2200 rpm. Doesn't matter how it runs at high rpm if thats not where you are going to drive it.

Leave the lump port heads for the race cars, you are not going to be running in the rpm they are designed for, just add bigger valves to your head and do some mild port clean up. Replace the pistons with 307 Chevy V8 flat tops, but sure they are true flat tops. Some of the replacements have deep valve reliefs and a deep chamfer around the top. You could end up with the same compression with the wrong pistons. True flat tops will put it around 9 to 1.

Ask the local shop if they can supply a crank, it shouldn't be that hard to find one.

Use a Offenhauser intake, they have smaller runners then the Clifford's. You will kill the air speed with a big intake, same with a big carb, no more then a 350 or 400 cfm four barrel. Use a long tube, small diameter tube header, not the shorty type. The 194 head will raise the compression, but needs extra work just to flow the same as a stock 230-250-292 head.

My stock 250 puts out 100 hp to the ground, I have dragstrip tickets and a certified scale ticket to prove it! My truck is a '37 Chevy with T350 trans and 3.08 gears, 235/75R15 (28" tall) tires, weighs in at 3350 and will run 75 mph all day long and thats with two Mono-jet carbs on a home made intake with stock exhaust. Last time out it ran 17.74 @ 73.67 mph, no speed demon but plenty quick for around town and good for 18 mpg @ 70 mph.

I guess you know the 250 will not bolt into the ch***is where the 235 was, it needs side mounts and a trans tailshaft mount. Its longer then the 235 so you may have clearance problems with the fan. Its also lighter then the 235 and the fan and water pump are mounted a lot lower then the 235.

If you want cheap torque, look for a 292, they pulled UPS trucks around for years....

Joe

 

Thanks Joe that is the strongest advice I've got so far. This is my first build and frankly was not aware the machine shop would provide parts.. (rookie move on my part). As for the mounts yeah I know it has to be moved all the way back .. Nathan hale from hales speed shop will be doing the motor mounts, trans mount and putting in front suspension so that when bagged it will sit on the ground. I already have the 250 so prob won't do the 292 unless when I take the block in they tell me it's ****.. Otherwise I'm exited to get my 54 on the road.. Thanks John

 

A front mount 235 style can be easily made to put in a 38 chevy pickup.

 

Look up www.cliffordperformace.com a phone number will be posted on the web site. Call the number and ask for Larry. I'll bet he can help you!

 

I am interested to know what you ended up doing? How are the results, my 230 finally made it into the machine shop 2 weeks ago. We decided after looking at the pistons, valves, seats etc that a rebuild was in order, .030 over 250 crank, 307 pistons, pretty much the advice Joe H gave. I was wondering if you did that and what you though of the results.

 

That is my exact setup, 250 crank, .30over, 307 pistons, hardened valve seats, offenhauer dual carb setup from langdons, langdons dual exhaust setup, hei distributor, t5 trans and 57 Chevy rear end 3.36 gears.. However I am not on the road yet.. I am bagging the 54 and hope to be on the road by April. From everything I've read and everyone I've talked to I should have no problem ideling down freeway at 75mph. We will see time will tell. This is my first build so the process is slow as know how is coming slower than time and money.. But I would rather build it myself than pay someone to do it for me.. Although I have had to pay for some help along the way. I will have a build thread going when I get towards the end as I have been taking pictures along the way. John

 

Good to see an update on this.
I've got a few pics of my 250 six in my albums, went with a mild cam, fuel injection and a 700R4 trans.
Runs well, 22mpg on the freeway and pretty strong.
I do want to get out of my Mallory Unilite and have Jim Linder at Bubba's build me a distributor. You should consider that as well if the ugly HEI bothers you.

 

And with your setup, I see no problems getting over 200hp out of that. You're gonna enjoy it!
What are you doing for exhaust?

 

I always buy parts through the machine shop.The shop's prices are as reasonable,and although I do my own engine ***embly,any problems with parts are dealt with by the shop,not me.Like the ring screw up on the ongoing 261 build.
My personal impression of Clifford is they are very expensive .....
Any shop that does a good job building high performance SBC's can handle a street build on a 230-292 .They know where to buy any brand of piston,cams etc.And being business if slow at many shops they will be thankful for the work.