Hey guys,

Pretty new to this site and to the third gen world. I have found a lot of great info on here, and now feel that it is time for me to take a dive to the deep end of the pool. I am looking to change out my 89 305 TPI set up with a 350 and have some upgrade questions.

I picked up a 350 block casting #14093638, roller block, that has been bored .30 over and the crank is .10 under ($60.00). No heads or cam in it. Here is some info I found on the pistons. Looks like they come from Flatlander Racing, and they are TRW pistons.

Specs:

Part #H631P-30
CID 355
Comp Ratio

58cc-10.41
60.5cc-10.11
64cc-9.73
68cc-9.33
72cc-8.97
76cc-8.63
Comp. Dist-1.560
Piston Shape-F/T
Price/Each-$28.00

I wanted to build it up a bit but not sure where to go. I dont want a speed demon, just want to spin the tires, and maybe beat a couple of college kids off the red light. Maybe 300-350 hp? I have a budget of $1000.00 and I dont know what heads to go with or cam to put in it. I want to use my TPI set up from the 305.

 

Nobody has any suggestions on this?

 

It's been quiet in here since I joined, I also need some help with my car after it caught on fire.

I know that the TPI system doesn't flow very well over 5500 rpm so you should cam your car to come strong on the bottom end and get it tuned for the extra displacement once your finished.

So port your heads, plenum, base and runners run as much compression as pump gas will let you get a good cam and some roller rockers and your motor should run strong and be very durable.

Hit me up I may not know much about a TPI but I know a lot about a SBC.

What are the specs on the heads you have now?

John

 

I think to reach your power goal, you'll will have to spend twice as much ($2,000). You should be able to save some $$ by buying used parts. Here are my thoughts. I haven't done any of this work but have researched into quite a bit for upgrading my car (stock 350 TPI to 420 with FIRST TPI).

Stock TPI intake is matched to provide enough air to a 305 engine and will have a specific boosted torque rpm range. Length on TPI system from runner opening at plenum to intake valve within cylinder head determines the intakes peak torque rpm and the boosted range. The diameter of the runners and base manifold need to be big enough to support the engine size and rpm based up intake track length. Cam duration comes into play since the intake duration value must match up with the pressure wave harmonics inside the TPI intake based upon it's length. Match intake length, diamater, cam duration and cylinder heads are much more important with TPI to realize maximum benefits.

A stock TPI can still make power on a 350 or 383 (http://xtremecarzone.com.au/index.php?showtopic=386). Good article showing stock TPI intake against aftermarket TPI intakes on a 383. A stock L98 engine with TPI will make 245hp anf 345 torque. It does make some decent power but dies after 4,500 rpm. The stock TPI can't properly feed to right amount of air to a 350. I love TPI intakes and think there are a great street intake. You can keep the stock TPI intake with your engine upgrade or get an aftermarket TPI intake for a better matched system to your 350. If you decide to get aftermarket TPI, you could keep stock TPI for awhile and get new heads and cam now. It is easier to do it all at once though. Which ever way you go, just plan out heads, cam, intake now so you can get the best matched system for max TPI tuned effect. Your intake decision will determine what kind of cam and heads you should get.

Here are some links showing air flow of different TPI runners on the stock base/manifold. Do not get caught up in higher is better, look for how the different bases match up with different runners.
http://hobracing.com/tech/tpi_flow.asp
http://forums.corvetteforum.com/c4-t...-remember.html
http://forums.corvetteforum.com/c4-t...-tpi-base.html

You can see from the numbers that the stock base is limiting factor even after installing aftermarket runners that flow more than stock runner. Yes aftermarket runners do add more air on stock base but an aftermarket base is needed for best results. People seem to favor the accell base. Add on to this larger Accel runners and you will have a good TPI intake for 350 and street use. There are aftermarket runners that are siamesed abit which move the peak torque rpm up a few hundred rpm since siamesing reduces intake track length. Even keeping stock TPI intake on 350 you will need larger fuel injectors. Adjustable fuel pressure regulator would be good too. Injectors and regulator would be a few hundred plus aftermarket, accel runners $330, accel base $400. So intake upgrade could cost $300 to $1000 alone.

If you get new TPI base, some aftermarket ones allow for attaching Vortec bolt pattern heads. Vortec heads are cheap, plentiful and should provide plenty of flow. There are some decent cheap aluminum heads too. Just need to make sure what you get has enough air flow for intake. Also look for smallest head that provides necessary air. 180cc or less would give good street throttle response. Your stock 305 heads would fit on 350 but would not work well.

Your car is MAF computer system which responds to engine changes better than MAP. Changing 305 to 350 means at least you need stock 350 ECU. You might be able to get away without tune depending on how aggressive your upgrade is. Might be able to get away with stock cams like LT1 which is more aggressive than stock, cheap and plentiful.

I apologize for rambling on and didn't mean to take discussion away from using stock TPI. I just don't want to see you go through upgrades and then be disappointed. Let us know what you think so we can help out.

 

Was also thinking of adding a stock LS1 cam. Would this work with the set up I'm going with?

 

Ha a fellow LAX. I too am about to start a 305 to 350 swap as well. As i type this im porting my TPI. I too am interested in any info you can get for this.

 

Really, is the camaro you have now on the road? Always looking for fellow third gen owners to swap stories and advice with. Feel free to hit me up, I'm on the SS of Lacrosse

 

I don't think you can just swap a LS1 cam into a gen 1 SBC. LS1 have different cam cover plate with cam sensor. I believe LS1 cam has a specific "cam" button that works with the cover.

Have you seen this thread? Guy wants to upgrade 350 TPI but keep it stock looking.
https://www.thirdgen.org/forums/tpi/...i-rebuild.html

Have you decided any further on what parts you might want to get? Our goals all come down to how much we want to spend. If $1,000 is all you can do, maybe we can start narrowing down some parts with an upgrade path.

 

Well going with the swirl port heads, going to port them out myself. Doing the same to the stock intake, runners, and penlum. Looking to sesemi them as well. Going to use the roller lifters from my current 305. Bought a stock complete 350 with ecm and harness(TBI) and going to use most of the parts from it. Going to do a roller timing set, just really hung up on this cam thing. I just want a torque monster for the occasional red light peel out. Not really going to be dragging it at the strip.

 

Nah atm its torn down getting a nice make over lol(and its a 91 firebird). Im down for that, would be nice to see some fbody caravans going on lol.

 

Yea, I would like to take a look at what you got going on. Always looking to pick up some knowlege on these cars.

 

Looking at this cam:

Comp Cams 08-500-8 - Comp Cams 'Xtreme Energy' Hydraulic Roller Camshafts Details

Chevy 305-350ci Small Block 1987-98
For engines originally equipped with a hydraulic roller camshaft, except LT1 and LT4.
Operating Range:1000-5000 RPMDuration Advertised:258° Intake/264° ExhaustDuration @ .050'':206° Intake/212° ExhaustValve Lift:.480'' Intake/.488'' ExhaustLobe Separation Angle:112°


Is this too little or too big? I am really having a heck of a time with this cam thing.

 

Dont quote me but i thought someone had said if you are going to use stock heads that .480 lift in/out is the max you can go before they start slamming. Like i said dont quote me....

 

biggest cam you can put in our heads is the crane powermax 2032 cam (part number 104224) its 214 220 duration .452 .465 lift on a 112lsa.. that will wake your mild tpi up...

 

Ok, thanks for the advice. I'm determined to get this right the first time, so I havent even turned a wrench on the two motors yet unit I know all I need. Also I'm looking to upgrade the suspension at the same time. Got any suggestions on that?

 

I am also doing a swap with my 5.0 to a 5.7 another question i have is the connections are different on my harness to the injectors on the 5.7. How could i put the right connectors on it to the old harness? (i have the right connections for it) or could i just change the injectors to the 5.o ones? would it matter

 

You don't want to use the 19lb injectors, you should run 22-24 lbs for the 350. It will run lean, and like crap.

 

Man that cam is pricey!

 

So how would i be able to change it from the harness? splice the wire from the harness to the 5.7 connections ?

 

Does anyone know what was the stock cam in a 85 sbc 350 roller was? What were the specs?

 

I think 1985 only had 305's and the cam was not a roller into 1987.

 

Ok, so do you know the specs on the 87 350 Roller Cam?

 

What about this cam:

Edelbrock 2209 Rollin Thunder Performance Plus Camshaft Hyd. 1500-5500 rpm Adv. Dur. 280 Int./290 Exh. Valve Lift .462 Int./.479 Exh. Lobe Angle 112 deg. 87 And Later Chevy Small Block

 

https://www.thirdgen.org/mods3

Scroll down to bottom of page for 87 350 roller cam specs

 

Great thanks for the link. Also here are the heads im going to be using. I plan to port them as well. Also, should I be using self alligning or non self alligning roller tips?

Rebuilt Small Block Chevy Swirl Port Throttle Body Injection or Tuned Port Injection cylinder heads. Casting number is 14102193. These heads have 72cc combustion chambers I took picture of CCing heads with 1.94 intake and 1.50 exhaust valves. heads have been completely rebuilt with 3 angle valve job, 8 new intake valves and 8 new exhaust valves.With .500max valve lift springs,Heads are fully assembled with 16 new Viton Valve stem seals.

 

Ok so I am now going to go with 906 vortec heads. The guy I am getting them from stated that they are off a truck. He is willing to sell me the heads complete, with the intake, fuel injectors, etc basically the full top end for 250. My questions is that he says its a 6 injector set up, and now i have a 305 TPI and a 350 TBI ECM. Will either of these work?

 

Don't mean to redirect the thread but I am in Holmen and would be down for a cruise. I rolled my 86z and it wont be back on the road until mid July but after that sure. I am also looking for a body man for some advice. Hit me up if you guys wanna get a local thing going.

 

Hey yea would love too. PM if you want to hook up some time, date and place. Always looking to chat with fellow 3rd geners

 

This thread seems a little ADD to me (jk) seriously though I am having trouble folloing the continuing train of thought. OK a couple of things. If you want to use the Vortecs thats great. You will need to buy the scoggin & dicky vortec TPI base to get the TPI to work. I believe its actually made by Edelbrock. To get the best performance out of that intake you really need to get it ported. I would consider finding a used set of SLP runners and porting/siamesing them. Their are plenty of articals on these forums on that. Now my htought would be have the vortecs eqiuped with spring/seat combos that would allow you to run a larger cam than what you were looking at. This really doesn't need to be expensive, check with a machinr shop.

 

I am having troubles with all of this as well. I think everytime I read another thread it gives me a new idea as to what to do. There are so many suggestions, options, and parts to work with Im just not sure what direction to go here. I think Im going to revert back to just getting the 355 running with a mild cam and the swirl port heads. Then once its in i can make tweeks and add new parts as I go.