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Author Topic:   Chev 400 Dart block w/Vortec heads....
STICK01
Dirt Full Roller

Total posts: 52
posted April 25, 2002 01:09 PM
Has anyone done this? Can I do it? What pistons will I need to use? My former engine builder assisted me in exploding my aluminum heads and scarred some of the cylinder walls on the brand new Dart Little M block, so now that I have to go 4.125 +.020 = 4.145 bore and a 3.75 stroke w/6" rods what pistons will I need for the Vortec heads w/2.02 and 1.6 valves on alcohol and will this work without a lot of fancy machine work?

If you need someone to help you explode engines let me know, I can give you a name!

Stick

sdhnc29
Dirt Freak

Total posts: 467
posted April 25, 2002 06:30 PM
Hey STICK01 ,

This can be done with no problem's , and relatively cheap . Call me again if you would like , and I'll give you the piston part numbers and combo . By the way , was I right or wrong in what I told you on the phone ??

Steve

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780

STICK01
Dirt Full Roller

Total posts: 52
posted April 26, 2002 08:43 AM
I and another engine builder locally here to me believe you were right. and are reassembling the heads to confirm that. Actually the local guy here is putting at least two rods/pistons together to put back in the engine and the head back on the engine to check all of the clearances. He believes that it could even go into the fact that when the prior builder put longer studs in the heads that the rocker arm geometry was ******* up and therefore caused the rocker arm to come off the tip of the valve, thusly causing all the carnage that was done. He had never seen that much dirt in an intake runner of a head either, and was very skeptical about how it got there, but in no other cylinder. Big mystery!!!! But he did not feel that it was what caused the problems that I had.

STICK

STICK01
Dirt Full Roller

Total posts: 52
posted April 26, 2002 08:48 AM
Steve,

Please send me the combo part numbers you had in mind. I had already spent $750 on the Vortec heads getting them ported and polished, new 2.02/1.94 valves, springs, and a set of selfaligning roller-tipped rockers (with the little guides on the sides) So, we were talking about putting my ***** in 7/16 studs in them to use my polylocks and stud girdle? Good or bad idea?
I am thinking of going with the 2916(i think) Vortec style intake. Any better ones out there?

STICK
modracer31@hotmail.com

sdhnc29
Dirt Freak

Total posts: 467
posted April 26, 2002 11:54 AM
I'll email the info to you this weekend . The self aligning roller rockers are a bad idea . I'd put your 7/16 studs in , and use a conventional roller rocker . If the 2916 intake that your talking about is the Super Victor for Vortec heads (I can't remember the part #) , then that is the one that you will want to use ! It's about the best intake available for your application .

Steve

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780

DEEDDUDE
Dirt Maniac

Total posts: 111
posted April 26, 2002 05:09 PM
Steve,

When running Vortec heads with guide plates do you still need the self-aligning rockers?

Thanks, Deed

sdhnc29
Dirt Freak

Total posts: 467
posted April 27, 2002 12:55 AM
No you don't . You don't want to use the self aligning rockers anyway . They are not meant for higher RPM , and they run a high risk of coming off . So use conventional rockers with guide plates if you going to race .

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780

istock59
Dirt Freak

Total posts: 237
posted April 27, 2002 11:27 AM
When you say "higher" RPM, what numbers exactly are you meaning?

I've used stamped steel S/A rockers for 3 years now, up to 6500+ RPM every night, without a single problem. 1.5 and 1.6 rockers. Flat tappet cam. H11 springs. Tight lash cam.

I even over-rev'd the motor one night to 8600, and they still stayed on!

They are a little harder to set the valve lash on, but once you get the procedure down, it's not that bad.

Until I have problems with them, I'll continue to use them...

[This message has been edited by istock59 (edited April 28, 2002).]

STICK01
Dirt Full Roller

Total posts: 52
posted April 29, 2002 10:30 AM
STEVE,

My engine guy here locally says that it may not be too good of an idea to use the Vortec heads on an alcohol engine...170cc intake ports too small for a 400? I am going to talk with him around 12:00 or 1:00 today CST so if you see this reply back...or if I get the chance I may call you.

Thanks,

STICK

sdhnc29
Dirt Freak

Total posts: 467
posted April 29, 2002 12:19 PM
Yes they are small for alky , but I was under the impression that they were all you owned now . They will run good on a 400 , but obviously you would be much better off with larger heads , like 230 Iron Eagles . Alky engines like big runner's , so if it's in your budget , I'd definitely use bigger heads than the Vortec's .

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780

sdhnc29
Dirt Freak

Total posts: 467
posted April 29, 2002 12:22 PM
Congratulations istock59 ! Your a lucky guy ! I've got three words for ya ...."BUY LOTTERY TICKETS" ..LOL Just joking !

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780

istock59
Dirt Freak

Total posts: 237
posted April 29, 2002 12:36 PM
Hendren, bring one of your motors up to IMCA claimer land, and we'll see how lucky YOU are. Bet you'd get great gas mileage on the way home tho!

[This message has been edited by istock59 (edited April 29, 2002).]

sdhnc29
Dirt Freak

Total posts: 467
posted April 29, 2002 07:45 PM
I hear ya istock ! LOL Just can't bring myself to give one away though .

Steve

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780

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