421 cube pulling truck engine

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randy331
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421 cube pulling truck engine

Post by randy331 » Fri Jan 19, 2018 9:02 pm

Buildin a new engine to go in my son's Pulling truck for next year (2018). It's for IAMO 6200 LB pro street.
Thought I'd share it and ask a few questions.
Below is a link to the rules.

https://docs.wixstatic.com/ugd/c23712_c ... b94976.pdf

The build, what I have so far.

Dart SHP PRO block, plate honed to 4.156" bore zero decked
Callies Magnum crank 3.875 stroke, 350 main 2" rod journal
Callies Ultra h beam rods 6" x 2" rod journal.
Custom JE pistons pistons with 11cc dome, vertical gas ports, a bit heavier than I'd like @ 499 gram
Compression is at 14.8-1 as of now without more milling (testing with slight dished valves)
Total Seal .9 x .9 x .125" x 2 mm rings. steel top, napier second
Crower endurx .904" lifters with offset intake
Comp Cam 274 in x .460" lobe lift 287 ex x .440" lobe lift, on 112 LSA big block journal
Jesel shaft rocker 1.7 in = .782" lift / 1.6 ex = .704 lift.
2970 intake, ported and matches ports well
1.59 venturi x 1.79 throttle bore 4825 series Braswell carb.
Spacers to try on the dyno
GZ sportsman vacuum pump

Heads are GMPP large port vortec bowties
Pushrod area is welded and opened to 2.6 ish csa
Curently valve job is set up for 2.08" x 1.58 valves ( not much room for more )
May be able to fit 2.09"
Ports are 235 cc-237 cc so far. Probably end up 240 ish
Heads still in progress.

Still need to buy intake valves. Going Titanium intakes. Got good access to Manley. They'd be about 88 gram
Got a new set of Ferrea f2247p 1.6" steel ex valves sittin in the shop I could use. 99 gram. I have them and it'd save a little money for tow fuel. LOL Gonna be a lot of miles on the tow rig this summer.
Any opinions on valves ?

Still need valve springs. Thinkin Pac 1325 springs ,but have good access to Manley Nextec?
Any opinions on springs ?
Titanium retainers?

Headers ?? It's a 1990 k 3500. Not a lot of header options and I'm not sure I have the welding skill to make a set.
Headers can't go out the hood.
Opinions on header sorce and size ?

If I made a set I'm thinking 1 3/4 x 1 7/8 step

I expect it will make peak HP about 7200-7300 but it will need to hang on to power past peak as far as it can.
And, it will need to make as much TQ around peak TQ as possible for when the track is tight and the sled guts the engine.
Probably test it on Q 16 and 114

What kinda power should I expect ?

Sorry for the long post. :D

Randy

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Re: 421 cube pulling truck engine

Post by pamotorman » Fri Jan 19, 2018 10:11 pm

i never built a truck pulling engine but why give up 50 cu inches to use a small block ???

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Re: 421 cube pulling truck engine

Post by Roadknee » Fri Jan 19, 2018 11:07 pm

I appreciate you sharing this build, Randy, and particularly admire all the durability parts.

Throttles performance built a set of Tri-y's for his truck. You can see pics for general ideas starting on page 3 of this thread

viewtopic.php?f=1&t=44425&start=30

I put your combo into Pipemax to get the HP discussion going. With 7,250 rpm HP peak and 110% VE it predicts 800 HP. 4 into 1 race header specs are 1.81" O.D. first step, 1.94" O.D. second step, both 15" long.

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Re: 421 cube pulling truck engine

Post by Old School » Sat Jan 20, 2018 2:00 am

Can the headers be fenderwell? Might be a straighter angle off the head.
Will the lighter engine allow you to hang weight more strategically?

Don't worry about the tow money. Pulling is just like drag racing, the money that can be won will cover all your expenses with a little left over. Problem is... somehow I never did completely grasp the concept on how that worked.

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Re: 421 cube pulling truck engine

Post by MTENGINES » Sat Jan 20, 2018 3:19 am

Roadknee wrote:
Fri Jan 19, 2018 11:07 pm
I appreciate you sharing this build, Randy, and particularly admire all the durability parts.

Throttles performance built a set of Tri-y's for his truck. You can see pics for general ideas starting on page 3 of this thread

viewtopic.php?f=1&t=44425&start=30

I put your combo into Pipemax to get the HP discussion going. With 7,250 rpm HP peak and 110% VE it predicts 800 HP. 4 into 1 race header specs are 1.81" O.D. first step, 1.94" O.D. second step, both 15" long.
Expect 730-750. Anything extra let's you know you are doing a good job. Looks like a cool build, keep us all posted.

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Re: 421 cube pulling truck engine

Post by Keith Morganstein » Sat Jan 20, 2018 8:44 am

randy331 wrote:
Fri Jan 19, 2018 9:02 pm

Headers ?? It's a 1990 k 3500. Not a lot of header options and I'm not sure I have the welding skill to make a set.
Headers can't go out the hood.
Opinions on header sorce and size ?

If I made a set I'm thinking 1 3/4 x 1 7/8 step

Sorry for the long post. :D

Randy
Shoenfeld has quite a selection. Something they make should work.

I'd want to use Shoenfelds fender well truck headers. 1346V, 1347V
but they are for 78-89 truck. IDK what the difference with a 1990. Shoenfeld has it in a weld up kit that might allow it to fit?

There is also the Shoenfeld 198VA,199VA S10 forward header to consider. And prob 20+ More SBC styles
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Re: 421 cube pulling truck engine

Post by Roadknee » Sat Jan 20, 2018 10:54 am

MTENGINES wrote:
Sat Jan 20, 2018 3:19 am
Expect 730-750. Anything extra let's you know you are doing a good job. Looks like a cool build, keep us all posted.
Pipemax puts it at 750 HP with 105% VE and the recommended header size exactly where Randy is considering; 1-3/4" x 1-7/8".

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Re: 421 cube pulling truck engine

Post by randy331 » Sat Jan 20, 2018 11:05 am

First, thanks for the repies.

As far as why I did a small block, well mainly that's what I wanted to build. It will end up in my Nova most likely,... if it survives a summer of truck pullin.
But there is a small weight advantage. The weight difference can be moved farther forward, but that won't offset 50 cube. Head choices are more with small block. GM only for big block.

As far as power, I'm hoping for 750 HP. My goal is to put 100 LBs TQ and 120 HP on the 355 we pulled with last year. So I'll need 600 Lb and 750 HP to do that. But,.. some of the things I'm doing to raise rpm will likely cost me some TQ, so....

Headers, rules say (headers must exit down and back) so that eliminates front exit, but should allow fender well.
Some of the Showenfeld fender well exit may fit. (thanks Keith) I think the main difference is the independent front differential vs the older trucks listed. It's tight on the drivers side. Already got the oil filter remote mounted to add room.
But, it may not be easy to get the fender well headers hooked up on the dyno.

Maybe I build a set that dumps behind the front tires and point the collector to blow the loose dirt away so the back tires don't run in the loose dirt from the front tires ??

But, if it makes 800 HP, well that's fine too !! :D

Randy

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Re: 421 cube pulling truck engine

Post by 77cruiser » Sat Jan 20, 2018 11:23 am

Give Calvin a call & get some input on headers.
Jim

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Re: 421 cube pulling truck engine

Post by Keith Morganstein » Sun Jan 21, 2018 6:14 pm

The rules say any aftermarket iron head for SBC. So would the the 14* RHS iron be allowed?
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Re: 421 cube pulling truck engine

Post by randy331 » Sun Jan 21, 2018 8:28 pm

Keith Morganstein wrote:
Sun Jan 21, 2018 6:14 pm
The rules say any aftermarket iron head for SBC. So would the the 14* RHS iron be allowed?
Well,.. yes, and I have a pair here in the shop,... but rules say standard bolt patern intake, so that'd eliminate using the spider type intakes for the 18*-15*.
And rules say no port plates of any kind on the heads, so that'd make it hard to fit a 23* intake to them.

But, the rules guy told me that head would be legal as long you use standard intake pattern.
And, according to my son, some of the others have port plates,...so ??

To my way of reading the rules, the only way to use the 14* proaction head (and be legal the way I comprehend the rules) is to weld up the flange on a 2970 etc, until it can be milled flat and fit the heads with no port plates.

To me "no port plates of any kind" would also include ex ports, and therefore header adapter plates.

But,... I didn't wright the rules, or enforce them.

Guess I could claim the same as John did on his mel engine at the EMC, those aren't port plates, there're intake gaskets. :D

Randy

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Re: 421 cube pulling truck engine

Post by Keith Morganstein » Sun Jan 21, 2018 10:15 pm

randy331 wrote:
Sun Jan 21, 2018 8:28 pm
Keith Morganstein wrote:
Sun Jan 21, 2018 6:14 pm
The rules say any aftermarket iron head for SBC. So would the the 14* RHS iron be allowed?
Well,.. yes, and I have a pair here in the shop,... but rules say standard bolt patern intake, so that'd eliminate using the spider type intakes for the 18*-15*.
And rules say no port plates of any kind on the heads, so that'd make it hard to fit a 23* intake to them.

But, the rules guy told me that head would be legal as long you use standard intake pattern.
And, according to my son, some of the others have port plates,...so ??

To my way of reading the rules, the only way to use the 14* proaction head (and be legal the way I comprehend the rules) is to weld up the flange on a 2970 etc, until it can be milled flat and fit the heads with no port plates.

To me "no port plates of any kind" would also include ex ports, and therefore header adapter plates.

But,... I didn't wright the rules, or enforce them.

Guess I could claim the same as John did on his mel engine at the EMC, those aren't port plates, there're intake gaskets. :D

Randy
I’d be wanting to use those heads, esp since you have them. There is the RHS 12091 intake.
I never thought of stahl type header adapters as “port plates” but, guess it would need clarification.
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Re: 421 cube pulling truck engine

Post by randy331 » Mon Jan 22, 2018 8:33 pm

Anyone use the Xts belt drives, buy xceldyne ?
# XTS90000

If so, what you like/dislike about them ?
What do I need to look out for when installing it ?

Randy

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Re: 421 cube pulling truck engine

Post by MELWAY » Mon Jan 22, 2018 8:58 pm

What is your reason to use the 4500 style intake?

I would think with the limited Cross section in heads a smaller 4150 intake might give more air speed and better acceleration
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Re: 421 cube pulling truck engine

Post by Keith Morganstein » Mon Jan 22, 2018 10:36 pm

MELWAY wrote:
Mon Jan 22, 2018 8:58 pm
What is your reason to use the 4500 style intake?

I would think with the limited Cross section in heads a smaller 4150 intake might give more air speed and better acceleration
Can’t speak for Randy, but he said it matches up well. He’ll need all the power he can make. If they’re pulling weight transfer sled, it’s a pull down situation. You get into the pull at high RPM, then the revs pull down as the load increases.
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