Advice on 351W truck motor please

General engine tech -- Drag Racing to Circle Track

Moderator: Team

Post Reply
mavbike
New Member
New Member
Posts: 6
Joined: Thu Nov 16, 2017 9:13 am
Location: Shreveport La

Advice on 351W truck motor please

Post by mavbike » Tue May 15, 2018 6:44 pm

Hello from another long time lurker, first time poster. I apologize in advance if the post is long. I have a small "hobby" machine shop. I do mostly vintage motorcycle stuff. Using information from this forum and a few other places, I have machined/built several motors that won championships. I've been away from the automotive stuff though, since the late 90's. (Before my current job, I did a lot of stock and mild performance v-8 stuff, but nowhere near the level I have seen here.) With the above being said, I'm no rookie, but I'm deffinately behind the curve on some things. The project I have now is on a tight budget and is for myself. I wanted to post and see if anyone spots anything I'm leaving open or forgetting.
What I have is a stock, recent remanufactured, 351W from an unknown shop is the Dallas Tx area. This motor ran good, no smoke, and no blow by, before I pulled it. I intended to do a tear down inspection (I check things as I tear down because even ruff measurments of dirty parts sometimes provide information.) First thing I saw when heads came off was that this motor was not honed with a plate. Cross hatch looks great everywhere except in corners by each head bolt. Felpro gaskets were used in the initial build. The pistons appear to be Sealed power, dished, cast. Just scraping carbon off the piston and a rough check, I get about .0258 deck on the passenger side and .036 or so on the driver side.
My OCD will not let me go any further or I will have to do the block and I'm out of money. I need the truck running.
Plan is to put a set of Trick Flow 170 heads on top. Using an available Cometic .023 MLS gasket should put me in the ball park for 9.2:1 with the dished pistons. RPM intake, new carb, cheap summit 1 and 5/8 tube, 2.5" collector headers. 2.5" dual exhaust with x-pipe.
Need help with the carb size and cam. This is going in a 79 4x4 Ford that weighs around 5500, has 4:11 gears, NP435 granny 4-spd, and about a 30" tire. 70MPH was about 3,200 rpm. I am adding a ranger overdrive unit that I already have so that will let me run overdrive at 70 about 2200rpm and just leave it out of overdrive for towing.
I liked the look of a Howards cam listed as 267/267, .050 was 200/200, with .543 lift on a 108 (ICL 106). That should work well for power and midrange torque while keeping it under 6000rpm for the cast piston. This truck is not an everyday driver, but will be used to hunt, play in the woods or occasional mud park, and some long road trips. Most towing is a light trailer loaded with race bikes.
Not sure about the above cam for valve train life (looks like a lot of lift for the duration but)??? Not sure on the carb size. I'm more comfortable with standard Holley, but am real curios about the Holley Street Demon 750 that is supposed to be a mix of Holley AFB and QJ.
Asking for thoughts/ideas/opinions.
Student, learning from those that have been there and broke thatπŸ˜€

Carnut1
Guru
Guru
Posts: 3669
Joined: Tue Jun 11, 2013 6:32 pm
Location: Melbourne fl.

Re: Advice on 351W truck motor please

Post by Carnut1 » Tue May 15, 2018 8:16 pm

I am interested in that cam. I run a 260 260 206 206 .533 .533 w/1.6 rockers on 110 lca in the old work truck but it is over 20 years old and a hydraulic roller. That does seem like a good amount of lift especially if it is a flat tappet. Thanks, Charlie
Servedio Cylinder Head Development
631-816-4911
9:00am - 9:00pm EST

B Original
Member
Member
Posts: 131
Joined: Tue Apr 17, 2018 6:51 pm

Re: Advice on 351W truck motor please

Post by B Original » Tue May 15, 2018 8:20 pm

I've built one really similar to this but he was a 170 trick flow heads with exception I used a Holly injection throttle body the cam I used was 284 advertised 224 at. .050 and .533 lift and 4 degrees advance it had a fairly smooth idle and about 17 inches of idle vacuum it had a huge torque curve from idle to about 4,800 I did not Dyno this one but on paper it should have made 370 horsepower and 450 foot pounds additionally this went in a 1979 F100 originally with a 4.9 3 speed manual and a 370 rear ratio using aod transmission from the late 80s with a gear train out of a 06 aode the owner want to keep it looking stock with 235 70 tires and you had to be gentle taking off or it would like the tires up

9.05-1 compression

mavbike
New Member
New Member
Posts: 6
Joined: Thu Nov 16, 2017 9:13 am
Location: Shreveport La

Re: Advice on 351W truck motor please

Post by mavbike » Tue May 15, 2018 8:30 pm

Howards Cams Hydraulic Flat Tappet Camshafts 220991-08

I was worried about the lobes being to aggressive for something I need to last a while for street use. My choice was the Howards or contacting Mike Jones. Budget says Howards with Isky lifters, but common sense says I may be leaving some mid range torque on the table if I don't spend the extra with Jones. Still not sure on carb size either. The street Demon looks good on paper but sure doesn't have a lot of on line tuning info or comments for how well is works.
Student, learning from those that have been there and broke thatπŸ˜€

mavbike
New Member
New Member
Posts: 6
Joined: Thu Nov 16, 2017 9:13 am
Location: Shreveport La

Re: Advice on 351W truck motor please

Post by mavbike » Tue May 15, 2018 8:33 pm

B Original,,, that is exactly the type of information I am looking for!!! If you don't mind my asking, what exact cam was that and what carb?
Student, learning from those that have been there and broke thatπŸ˜€

B Original
Member
Member
Posts: 131
Joined: Tue Apr 17, 2018 6:51 pm

Re: Advice on 351W truck motor please

Post by B Original » Tue May 15, 2018 8:53 pm

It was a Holley four barrel throttle body injection the cam was Custom ground by competition cams that I ordered through Terry Walters and I forgot to mention it was flat tappet I'll try to get you the lobe profile number and post it later and it was a really mild ramp so I would imagine a Springs have a long life

B Original
Member
Member
Posts: 131
Joined: Tue Apr 17, 2018 6:51 pm

Re: Advice on 351W truck motor please

Post by B Original » Tue May 15, 2018 9:08 pm

I just found my original notes on that engine build and I told everyone wrong in my previous post all the specs were correct with exception of the cam 256 advertised 212@.050 107 lsa .519 lift with 1.7 rockers single pattern Terry Walters part# for the lobe was tsfw 5087 -07 if you lock this cam PM me and I will see if I can get you hooked up with Terry and have you get exact same cam from him

fastblackracing
Member
Member
Posts: 71
Joined: Sun Feb 15, 2015 12:13 am

Re: Advice on 351W truck motor please

Post by fastblackracing » Tue May 15, 2018 10:33 pm

Mavbike FYI that cam you have listed 220991-08 is 220/220 duration at .050".....
the give away on that was the 67* spread between the at 50 numbers and the
advertised duration numbers of 267.

If it truly were a 200/267 lobe that would be 1 very slow cam lobe.....most
hydro flat tappets will be around a 50 degree spread.....a bit less shows it to be
a faster ramp and a bit more would be a slower lobe....and yes there are other
durations at .100,.200,.300 and so on to really tell the tale but thats not the point
of this post.

I think that cam B original is telling you about would be good for your deal.....
with limited and unknown compression, a heavy truck and tall tires I would not be
going over 215 at .050" if it were me...and tight on the LSA.

and best wishes on your build.....above all have fun!

B Original
Member
Member
Posts: 131
Joined: Tue Apr 17, 2018 6:51 pm

Re: Advice on 351W truck motor please

Post by B Original » Tue May 15, 2018 10:52 pm

For what it's worth to you that cams 125 degrees at .200 Miner intensity is 44 and major intensity is 131

mavbike
New Member
New Member
Posts: 6
Joined: Thu Nov 16, 2017 9:13 am
Location: Shreveport La

Re: Advice on 351W truck motor please

Post by mavbike » Wed May 16, 2018 4:18 am

Fast black,, my typo, thanks for the catch. Yes 220 at .050

B Original, thanks for the information
Student, learning from those that have been there and broke thatπŸ˜€

jeff swisher
Guru
Guru
Posts: 1007
Joined: Wed May 23, 2007 11:13 am
Location: yukon ok.
Contact:

Re: Advice on 351W truck motor please

Post by jeff swisher » Wed May 16, 2018 8:01 am

I built a towing /play toy / family vacation E150 Van years ago.
I had a 302 with flat tops and smogger heads from 1982 with small valves.
I ported the heads and the 2V intaka and the exhaust manifolds and tried stock cam advanced 4 degrees and a 260H cam which was 212@ .050 .447" lift and 110LSA,106 centerline
That cam rewarded me with more power and better MPG.
I would normally get 17.6 and could get that or 16.7 towing my bayliner to the lake or towing a car on a trailer.

AOD trans but I did not ever use OD too steep for the 302 to pull it.
350 rear gears and 29.5" tall tires.. sometimes I ran my 33x12.5x15 mud terains I lifted the van 4" over stock and added extra shocks up front to have 4 shocks on the front. 2 regular and 2 overloads with springs on them.. Yes I bent the I beams to correct camber.

Great all around vehicle and 6000 lbs it would et in the 1/4 at 18.0.
Not fast but not bad for the weight and small cam and 2 barrel 302. I ran 3" single exhaust on it also.

I wish I had more compression.
My buddies van was almost the exact same but he had a 351W HO with the holley 4 barrel I would out run him pretty easy by many length in a race.
I also raced another friend with his 91 chevy Z71 with 350" that he put all kinds of speed parts on and he ran 18.2 et.

I tried many carbs on mine Qjet and holley and AFB along with many motorcraft 2 barrels.

The carbs were all tuned to get best MPG and power not a difference between any of them once tuned.
SOOOO Keep the regular holley if you have one and you know how to tune it like you said.. that will save you some money.

I just stuck with the motorcraft 2 barrel.. i never had any issues with the thing in the 13 years i drove it.

I think you are in the ball park on your build and the 220 duration does not seem out of line unless you want a bit more MPG then i would cut that back a bit and go 110 LSA or wider.
But if it is more full throttle power play then the 220 on a 108 would be the ticket.

I drove my van all over the west and central USA and MPG was very important. best I got was like low 20's coming out of Arizona.

mavbike
New Member
New Member
Posts: 6
Joined: Thu Nov 16, 2017 9:13 am
Location: Shreveport La

Re: Advice on 351W truck motor please

Post by mavbike » Wed May 16, 2018 10:44 am

Jeff, some of your previous posts and your Dodge with the 350 is what had me looking at came in that range.
I believe it was you that said you only lost a little mpg with the comp 268h on 108. MPG is a concern, but since it won't be a daily driver, I can give up a little if it ganes more power in the mid range.
The 4:11 gear with Granny 4spd, towing should not be a problem. For those not familiar with it, the ranger unit I have is a 2 spd that goes between trans and engine, low is 1:1, high is .27 over so it can be used to "splt"" the ratios on the transmission and as an overdive.
Student, learning from those that have been there and broke thatπŸ˜€

travis
Pro
Pro
Posts: 338
Joined: Sun Mar 15, 2009 5:31 am

Re: Advice on 351W truck motor please

Post by travis » Fri May 18, 2018 8:59 am

For a flat tappet cam, the crane 272 energizer works extremely well in heavy vehicles with 9:1-ish compression, and gets very good fuel economy too. It is 216/216@.050, .484/.484 lift, 110 lsa with 5* advance ground in. I’ve used this grind in a lot of trucks...350’s and 351’s...it flat works.

Depending on exactly which stock replacement piston is in there, it is most likely going to be a 17 or 19cc dish. I think .027” is the thinnest sbf head gasket Cometic makes off the top of my head. I would get the decks equalized if nothing else.

cuisinartvette
Guru
Guru
Posts: 1515
Joined: Fri Sep 05, 2008 11:39 pm
Location: Valencia Ca

Re: Advice on 351W truck motor please

Post by cuisinartvette » Fri May 18, 2018 10:37 am

81 4x f250
Stock compression, 212@050 type HFT cam, headers, 600 cfm carb. Towed a race car all the time, torque was decent, driveability like stock.
Think it was an XE 4x4 cam if I remember.

mavbike
New Member
New Member
Posts: 6
Joined: Thu Nov 16, 2017 9:13 am
Location: Shreveport La

Re: Advice on 351W truck motor please

Post by mavbike » Fri May 18, 2018 3:53 pm

Thanks for the reply so far.. I had to start getting parts one the way so I can get this thing back on the road. (302 that was in it when I got the truck had the balancer shatter at the rear of the hub and put metal through the motor. I've seen crank brank on 302s but never seen balancers shattered.)
As bad as I hate it, I'm going to have to half a$$ this one. As soon as funds allow, I'll look for another block and do it right. I'm going to try the Howard's 267/267 (220/220 at .050) on 108, intake 106, .543/.543 lift.
At least when I do the next one, I will have a better base line for what I like/don't like about it,, instead of asking Jones to work around what I have, I can give him the head flow/bore/stroke and let him choose the compression to work best with his cam choice for what I want the motor to do.
Student, learning from those that have been there and broke thatπŸ˜€

Post Reply