Inliners International Forums General Discussion Hi Performance 230 build up

Right now I'm toying with the idea of adding lump ports (hi-flow's) and a new cam to the 62's engine.
Right now the car has enough power to be a blast to drive but I want o add a little more punch to it. So far I have added Offy intake 390 holley carb stove bolt header and 2.25" dual exhaust and a 4speed.
i was thinking of this cam from PAW
Duration @ 0.050 Lift: Int. 224° /Exh. 224°
Advertised Duration: Int. 290° /Exh. 290°
Gross Valve Lift: .509"/.509"
Deg. Lobe Center: 110 LC
I hope with the lumps and the new cam I will not loose any on the bottom end but gain more on the top end
Thanks
Jon

I will say this,,,you are using the correct intake manifold.

What is the compression?


MBHD

Jon,
Are you running a stock cam now? If not what are the specs? Tom

as far as I know the cam is stock. Oh yeah i have a HEI form a 75 250 installed. The head is a newer head with "small" spark plugs (5/8" socket) I have not looked up the casting number yet. The block may be a 250, will not know until I get the head off for the lump port, the casting number says it is a pre 67(no vin number in block)230 or 250, guessing that it is a 230. I have no idea on the compression, I just know the thing runs great!
Thanks

Well if it's all stock head & pistons,if you switch to that size camshaft w/approx 8.4:1 compression, I would say you will loose a bit of the low end grunt.

This is where the 194 head comes into play,smaller chamber for a larger than stock camshaft work well together.

Just my 2 cents.

MBHD

What kind of power are you looking to make. How do you want it to idle? RPM range?
You are better off building your head than a 194 head. Hank and I will disagree. Too much shrouding takes place with the 194 head and the average mods done to a open chamber head like yours will not be enough to wake up the 194 head.
I do have a couple of cam suggestions.
1. Tom langdons marine cam
.442 lift, can't remember the duration(it is under tech tips to the left)
2. I have a custom grind that will really work well also. Only .424 lift , but will really wake up your engine. Tom

Tom you can disagree all you want.
It's a free country.

I'll disaggree w/your statemnet on the 194 cyl head.
Your findings are you findings,that great.
I also have my findings.

There are certain scenarios where the 194 cylinder should be used & is a viable option when you don't want to keep changing pistons to add ot remove compression.

MBHD

is this the cam you are referring to?
“292 H.O. Marine” 262 / 262 0.442 / 0.442
then there is this one
"Chevrolet L6 194, 230, 250 1962-1984
Duration @ 0.050 Lift: Int. 194° /Exh. 204°
Advertised Duration: Int. 260° /Exh. 270°
Gross Valve Lift: .464"/.490"
Deg. Lobe Center: 110 LC
There is a custom cam grinder in my area that I can have him grind me a custom cam. was thinking something in the 470 lift and 218-220 duration at .050 an 106-108 lsa

I think I have decided on this cam
http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=60&sb=2
appears to give me the range I will use it in. I'm I correct?

That cam should be a great performer in the 230. Are you going to do anything else to the head besides the Bolt in lumps? Tom

I'm thinking that will be about it, would the power gain be worth the price to have larger valves installed? Right now the car will do 75mph up a 7% grade, what a time to find out your spedo is off!

Personally, yes. I think it would be a power gain to put in the larger valves.

Don't get me wrong, I'm all for budget builds. But, it'll definitley help the engine breath, especially when coupled with lumps.

Any pics of your ride, by chance?

-Sam.

This car is actually my wifes car, I have a 63 Chevy II with a straight axle currently under construction.
The 62 is rough it needs new rear wheel well lips aa ton of body work, but the complete drive train has been gone through and we have added disc brakes, rack and pinion steering is on my list of to do's. We jusst gotthe car on the road last summer, three days before the rear end im my truck went out, what a way to get thrown into daily driver status.

Installing larger than stock valves are good to a point.

Depends on your goals.

If you go large ,say a 1.94" the port velosity drops a bit & could posibly loose a bit of the part throttle grunt & low end grunt?
But,,, @ W.O.T you will see an big increase along w/other supporting mods.

Anyone conquer?

If you do the camswap, I would also like to see you to increase the compression ,if you can I.E milling the cyl head,Or like I said use a 194 ci cylinder head & insatall a 1.85" - 1.90" intake valve.

You do not need ( & I would not suggest ) to install a 1.94" intake valve in the 194 head, especially if you do not unshroud the chamber walls.



MBHD

The 1.84 valves are they 305 valves? How much should I take off the head? When do you sart running into cam/compression issue that would require youtorun premimun fuel? I'd like to keep the thingfer with 87 octane if possible. What isa good roller rocker to use?

Nice looking car! With a light body like that, I bet it does scoot real nice.

How soon do you want to put your lumps in? Going to be testing a 250 with different heads and cams in the coming month(s) on a dyno.

From the testing done so far on a 292 the 1.94 valves produced the most tq in a open chamber head like you probably have.

For the rockers the 3/8" studs you have will limit aftermarket choices. When reworking the head get the studs pulled and milled to accept 7/16 BBC studs, than you can run any # of BBC rocker arms you want.
Get the head milled about .030 and the chamber will be close to 70CC. That should be plenty of street compression. Tom

It will be Sept. at the earliest I may have a couple trips comming up, and so not know when I'll be going or when I'd be back. .030 off 3 angle valve job (1.84/1.50 valves) and 7/16 studs for rockers.
Yes that little car scoots real nice

Yes the 305 uses 1.85" intake valves ,which if used will give you greater port velosity that you will feel over running the 1.94" valve,especially in the lower RPMs which most typical driving is in the lower RPM range.

Also,the 1.85" valves will be better on fuel over the 1.94" valves,if that's a concern.

I am pretty sure if you cc'd your cylinder head,measure how far down your pistons in the hole. Add up all those CC's.
Poor deck height,most likely.

Your engine probably has 8.2- 8.5:1 tops, that is why I suggest running the 194 clyinder head as to bring up your compression ratio closer to 9.2-9.5:1

Running a 1.85" intake valve in the 194 cly head does not require much chamber unshrouding, & really not too necessary for your application.

I would throw in some 1.60" exhaust valves also.

Hope this helps.

MBHD

WOW 3 years.... and I am finally getting around to buying parts:) I cannot afford to do really any head work now, so I need to get the most out of my stock motor (140 HP 230). I still have the Offy/390 and stovebolt header. I need new springs as the valves float at about 4200 RPM. I also want to change the cam. I want power from 1800-5000RPM. I have a 3.50:1 geared Saginaw 4 speed with 2.41:1 rear gears (it is driven like a 3 speed with over drive) and 205/60 15 tires. I do some 1/8 mile drag racing. So where should I take this engine??