Pontiac 350
 

Starting a thread for all things Pontiac 350. Post up your dyno numbers, track performance numbers and engine combinations. Judgment Free thread.

I used one years back in a turbo combo project, detonation re-positioned most of the ring lands into the oil pan.
I believe it could make for a very good high boost lower (7000) rpm turbo combo, if used with splayed caps,dry decked etc etc. It's still an over square engine despite it's small bore - just look at what the iron 5.3 LS truck blocks are achieving with an inferior deck/small diameter studs. I sonic checked an early 350 a while back, bore walls were around .200" IIRC, and the mains bulkheads were pretty thick too. The block certainly weighed more than a couple of 400 blocks I had.

Bruce Fulper built a real potent 350 -several years back,

Can''t remember which mag it was a featured build in.

maybe someone else has a link


IIRC 540 HP on pump gas
\

Jim,my 366 std deck build is on this site,V heads.Now stay off here and do my intake!LOLTom

:wife:

Lol.....

Yes he sure did... He copied much of my build!

AFTER I purchased all my parts from R&RE and built my 350 at the Auto Hobby in Aviano Italy. Back then the internet was not what it is today and I purchased all my parts from R&RE while stationed overseas. Spent lots of time on the phone with Bruce talking about the build and spent lots of money with him as well. So he knew exactly what I did to my P350 and he seemed to like it so much he decided to build a similar 350 himself.

I do believe I was one of the first if not the only people to shoe horn a set of 72cc EDL RPM round Ports to a P350 Firebird back in 1997ish...

My engine was .040 bore with 10.75:1cr and ran great on pump gas. I dont recall the cam specs however I still have it, Ill go take a look and see if it has any numbers on it.

over 10 years later I learn that Bruce built and published an article (well after my 350 build) on a similar combination... I kind of expected to read some form of credit given towards my build... but no credit given.

Anyway, the car ran a 13.5 @ 108* <--- Trap speed was good for 12.5x potential but that was with a 10 bolt peg leg (one wheel wonder) . It basically spun one tire all of first and most of 2nd. With traction it would have ran high to mid 11's, I later on added a 4.10 rear gear and an Auburn posi and 6pt roll bars however never got back to the track with that combination. If I had to guess I would say it put down just over 400RWHP and 480ish crank.

Anyway, if I where building a P350 today, I would use the EDL RPM heads out of the box, do a .060+ bore and add a forged crank and run 10-15lbs boost.

SPEED SAFE, NICK

Wow - learn something new every day.

So your engine was the catalyst for the build.

I just remember reading the article and being kind of blown away by the HP the pump gas 350 produced for its time. Seems like the writer was so surprised that they Tore the engine down because they did not believe it was really just a 350 cube engine.
Yeah I don't remember any credit given for the 1st iteration or builder, just Bruce RRE.

My hat is off to you Sir.

It would be great to have your complete build listed, Kind of a "Broke the mold" engine.

heck I have couple P 350's sitting , maybe someday with the right project car. :)

Not going to bring up this guys name , as im not sure if this guy is on here but had a potent 354 build... this was his reply

.455SD rods, light venolia pistons, RAIV 722 heads ported to 310 cfm, ( far easier with aluminum heads we have today) 2.02/1.71 valves, 59cc chambers, pistons .005" out of the hole, stock gm head gaskets because they match the bore, today I'd use a victor intake, instead of the cut and wielded, ported Holley street dominator, 2" to 2 1/8" headers. 1050 dominator on a homemade tapered wood spacer of if a 2x6,( that was 2 tenths over the 800!!!) Cam was a custom backwards grind by UD Harold, 274/267 @.060", lift was .620"/.600" on a 111 LSA. Dual point Borg Warner distributor set up on an old sun machine. Added a second oil feed in the mains,

Can't talk about Pontiac 350 engines, in the race section, without mentioning all the quick national record holding '74 Venturas that have run, thru the years. They've won big races & got class wins at Indy.

Bill Rink ran quick in Stock, & is still quick with his '74 GTO, in SS.

Also been some quick '77 Birds running a 350, in Stock & SS. Mike Morgan still runs one in a '77 SS Formy. He's won class at Indy & has been R/U to Bill Rink several times.

Member Adam Strang ran some 10.80's with his 350HO powered '68 Bird Stocker.

My Pontiac friend, who is also a member here, won quite a few dirt races with a Pontiac 350.

That’s impressive, and that guy sure has a bad rep.

Here is the build for the Royal Pontiac 1969 350HO Firebird that ran in the Super Stack class, SS/J, that pulled an 11.92 1/4 mile time.

The other build is the Fulper specs for the 540HP 350CI magazine article.

Attention must be given to the valve-to-bore clearances when using the larger valve heads and the bore will need to be notched if it does not have them.

On the Fulper engine do they give cam spec's? Does it say at what RPM it made 540 HP?

Stan

'68 Firebird NHRA Stock Eliminator 350 HO combination. The best it went was 10.80 @123 mph. Minimum weight is 3220 weighed 3300. I was still finding the sweet spot with the clutch that I just had freshened so the 60 ft was off.
.080 over bore,block filled halfway up the coolant holes,stock stroke,Eagle rods and CP pistons. Stock 140 intake and Q-jet carb, .420 lift cam and #18 heads that flow 200 cfm.
Shift at 6200 rpm and cross the finish line at 7k.

Did some updates this past summer the motor is back in the car for next summer,hoping for some 10.60's.

"...The best it went was 10.80 @123 mph...weighed 3300...stock stroke, Eagle rods and CP pistons. Stock 140 intake and Q-jet carb, .420 lift cam and #18 heads that flow 200 cfm.
Shift at 6200 rpm and cross the finish line at 7k.

Did some updates...hoping for some 10.60's. " :cool:

Now, for all you "experts" that do all sorts of calculations, exactly how much cam & head flow is "supposed" to be needed to make that much power ? :D

It's not just how much the motor makes for power but also the car it's going into.

The quickest 350 powered '74 Stocker I'm aware of has run some real low 11's. Don't think it's dipped into the 10's, yet.

It's driven by Brad Koivisto. Was a GTO for years. This year, I noticed that it has a flat Ventura hood. Don't know if he got tired of having to deal with the shaker, or if there is a performance advantage, when running without it.

Reminds me of the 1974 US Nats. Al Vanis won Stock, in a Ventura. Rock Running won his class, in a '74 GTO.

Adam,
Thank you for the additional information. I have added it to your 350 entry on the list. If I have missed anything, typed something in wrong, or you would like anything updated please let me know. Since you maybe the only stick car on the list can you share who's clutch you use?

PMD Heads and Block List.
http://www.magneticlynx.com/carfor/pont_pmd.htm

Stan

There is NO fixed calculation for HP per cfm. Based on the estimated HP on the list he is at 2.5 HP per cfm.

Stan

All I'm going to say it's sintered iron!��

For those of you interested, this gentleman has a multiple series Pontiac 350 build on Youtube. The first video: https://www.youtube.com/watch?v=cdNhF-UCsX4

Here is a 350/383 stroker build - 462 horsepower at 6,100-rpm and 436 lb-ft of torque at 4,400 rpm.

https://www.hotrod.com/articles/hppp...-engine-build/

No, I don't recall if it had the specs or I would have them - might have been a "Fulper Secret."

There was another article done on the same engine using nitrous, 672HP. The cam specs are listed and may be the same for above.

Comp Cams Solid HR.
Duration at .020" - 285/Int, 296/Ex
Duration at .050" - 255/Int, 260/Ex
1.5 rockers - Lift .538" Int, .538" Ex (these numbers not clear, but under .580")
Lobe Center Angle - 108 degrees
Installed Intake Centerline - 100 degrees

No cam expert, but do the .020" and .050" numbers look true - this is what was shown in the article. Maybe backwards?

More specs on this engine included in the text. Keep in mind, these HP/TQ numbers were not necessarily accepted by others.

Jim,
Thanks. Yes for those 0.020" numbers the 0.050" numbers are possible.

Stan

Adam,
Thank you,

Stan

back in the early 70.s I had a 69 Custom S with the 330 hp 350 and a 4 speed with 3;55 posi -- It was a beast and ran with almost anything around. Had 48 heads If I remember correctly .

The very first 350 we built I remember being totally caught off guard how well it ran. Years ago we built some 455 Pontiacs to run in a street stock class dirt track that you could run any combination that the factory did as long as you had a cast iron intake, factory carb and exhaust manifolds, no roller rockers or head porting. But no cube limit. It was a blast to watch, because it put brands against brands and there was a good representation of Ford, Mopars, and Chevies.

We were learning yet and a car we were sponsoring had a 455 came apart. So to keep in the points race we ‘thru’ a 350 Pontiac together out of parts we had laying around. We completely expected the car to be lap traffic, but it wasn’t. It was not near as speedy coming out of the corners to the solid cam 462 and 466 the car usually had. But by mid track it ran with all the other cars. Most everyone still thought it had the 455 in it yet. Using what we had laying around: 350 with a set of big valve 96s milled .070, the compression couldn’t have been very high, mid to upper 8s scr, ram air manifolds, stock intake and a q jet. I don’t know what the specs for the cam where, maybe someone on the forum does. It was a Isky solid roller cam ground in the mid 60’s. We ran 1.65 rockers. (Rules didn’t say anything about roller cam :))I remember the cam was called a Isky 505. It was the same cam that set the national et record in the mid 60s by the white 64 stan long sponsored tempest. It sounded awesome, and we were shocked how well it ran

I ran a 350 back in the mid 90s with 670 heads that had a home port job. They flowed 240 cfm at .550 lift. My Firebird had 4.11 gears with a turbo 400 for a transmission. My torque converter was a bit too tight for the comp 295s cam, but it came on strong after the initial bog of not quite being in the power band. At Topgun raceway in Fallon, NV it ran a 13.40 at 106 mph. That track is about 4000 foot of elevation and has a DA of 8000’. A lot of people thought I had NOS do to how the car came on when it finally got in the RPMs the cam wanted to operate at.

Decades back my buddy Paul and I put together a garbage smog 350 short-block from a sludged 73-76-ish vintage one that was under a table at a high school shop class. We cleaned it with Easy Off oven cleaner and put new rings after a drill glaze breaker hone and re bearing same size. I got a old used 125000 mile #066 cam from a 68 428 I had pulled and we used that, A set of #62 big valve heads and it went into a 78 Grand Am with log manifolds a stock stall th350 and a open 3.73 monte carlo ss rear .. car actually ran a 14.3 or 14.4 @ 95 like that in street trim. Fast forward to 2020 and met a Abilene bracket racer with a beater 69 lemans that was a 330 hp 350 HO 4 spd 3.55 car but by now was a still a 350 but a automatic with 10" converter a 224 ish cam and 4.11 gears , a 600 edelbrock. I think he had #13 or 670 heads now, Old motor had freeze cracked in half and only had 1 one 48 head when he got it. That car gets ran a lot in NHRA brackets and he went to Memphis for finals this year. Car has gone a best of 8.1 in the 1/8th at my local XRRP track and often 8.2's with a 12.9 1/4 it did some time years back,, a legit simple 12 sec 350 lemans !

my 1968 350 ran strong on the original 2bbl and also the 4bbl. Had the original dividered cast iron manifolds. Great engine.

Was miffed when studying PMD parametrics and found the common crank for 326-400. Pro-400 mindset. But i skipped 400s in my stuff.

428 and 455 sure had more TQ, low end, and surely more HP.

Here are the dyno numbers on my 350 in my lemans. Just had it done end of the year. Not bad for a 40 year old rebuild.

In lookin back thru this thread, I saw this link to the 350P video series. Although the guy was obviously not a Pontiac guy, I enjoyed the series.

So, that got me to wondering if there were any other good 350P videos on You Tube. Just ran across this series. Since I never worked in a machine shop, I really enjoyed seeing some of the engine building machines in action.

This particular video is about grinding the crank rod journals. For others like me who have never really seen what's involved, you may enjoy it.

https://www.youtube.com/watch?v=12UdcpXHxPM

This one is grinding the main journals.

https://www.youtube.com/watch?v=GLDO56liwsI

Balancing the assembly & polishing the crank.

https://www.youtube.com/watch?v=zwDRGNNl5qk

Shortblock assembly. Methods & opinions differ.

https://www.youtube.com/watch?v=TnyrvGtMIfA

Sure thing... this may well be the ultimate Pontiac 350 build and it's currently under way. Spoiler, his plans include aluminum rods and heads.

Pontiac 350 Dyno Mule Disassembly....

https://www.youtube.com/watch?v=XpwN7XIVMYs

Pontiac 350 Dyno Mule Update...

https://www.youtube.com/watch?v=Qc2xemg-Mro&t=193s

Pontiac 350 Project PJ Connecting Rod Overview

https://www.youtube.com/watch?v=g4zGeVfM7Z4&t=55s


This builder does a lot of work with FE builds, seems fitting since I've always felt Pontiacs and FEs have a lot in common.

I maybe wrong, will not be the first time. But I believe Brent Lykins was a member here and got band for some reason.

Stan

Current build is std bore 350 with ancient TRWs and SIR rods. Flat tappet cam and ported 17 heads. 8.8 comp Dynoed at 380hp/420tq. In my 73 Ventura street/strip car it has run 12.49@107 on 89 octane in crappy air.

Version 2.0 is nearing completion. Much lighter rotator, hand ported KRE D-ports which I bought as 65cc chamber to be able to fit it to the small bore. Roller cam. Also currently installing a bar along with suspension upgrades . Shooting for low 11s with a pump gas 350P

Brent is a very experienced builder across many brands, some did not have an open mind to information he shared. Brent left out of frustration but should not have been locked out.

I suspect many of the same who disliked Brent would bite at Tony (BES) or Kaase if this forum was to be so blessed with their presence. :) There is nothing 'same old' about them, they are cutting edge, science and fact based. Same as Vizard.

Would you have the cam specs on the flat tappet that you used in v1.0?
I just picked up a ‘69 Firebird with a 350, and I’d like to build it up.

Yup

Howards Rattler. I used solid lifters on it and lashed at .006 intake/ .008 exh. Sounds healthy and super torquey/responsive.

2.0 update
 

Sorry I got a little behind on this. Dynoed the 350P version 2.0 back in January. It made 584hp/522tq! 10.7 comp on 93 octane.

Got the Ventura finished and to the 1/8mi track over the weekend. Best of [email protected] so far at 3,450lbs through exhaust. Converter is a bit tight and still have s lot of tuning to try. Swapped the PP Crosswind that made the prettiest dyno curve for the Victor that made the highest peak numbers and lost a TENTH! Tuning was limited Sunday as my wife bumped me out of my normal bracket ride so I jumped into competition with the Ventura and went 5 rds🙂

Back to the dual plane and a few other small changes this week then going to Mason Dixon for some 1/4mi fun. Updates soon

From post #26- "I don’t know what the specs for the cam where, maybe someone on the forum does. It was a Isky solid roller"

Jay, Not sure if its the same Isky solid roller but back in 2019 you mentioned a Isky solid roller from their 901 series. It was a single pattern with 290/290 advertised.
The .050" duration was 252/252 and ground with a 112 lobe separation.
The lobe lift was 0.3170" and 1.65 rockers . The cam card suggested 0.025" lash.

The grind # was RR-505c62


.

Steve the cam in the 350 was a little bigger with more lift. I recall it had around .34” lobe lift, i don’t know the exact specs.

thats very cool gives me hope for my project. i wtsh you well.

74 GTO 350
 

I have 3 74 GTO's 1 is a probracket car, with a stroked 400, nest is a pure stock automatic car, other is a HB project.
I am rebuilding the stock 350 for my street car.
My question is what is a good cam for the 74 350? Mileage is not a concern, just a good street cam that will put some muscle in it, a good sounding idle wont hurt either.

Good power. What RPM peaks?

The 200 hp 350 GTO motor still came with the 066 cam which was the base line 400 cid cam.

If your sticking with exh manifolds I would run something close to the factory 067 cam but with 1.65 rockers .

Your number 46 heads should already have screw in studs so change them out for aftermarket ones .

In stepping up the Cam I would also mill the heads .045” .

Steve, I realize this is minutia, but all '74 350's (both 2-bbl & 4bbl/GTO) came with the 483555 low performance cam ('W' stamp on nose). Same with the 400 2-bbls.

It would have been great of the GTO 4-bbl 350 had the 066 cam.

Dennis