235 cruising and max rev speed

[Michel]

I have drived the truck on last sunday for the first time. I have installed a tachometer and have noticed that the engine is not so happy to go above 2200rpm which give around 30mph. Followers were not so pleased...
I think that I will need to work a little bit with ignition timing. I am wondering what is best engine running speed 2000, 2500, 3000? and max rpm this engine can support safely?
Engine is stock 235
Thank you for your help.
Michel from France

[OrrieG]

Here is the original GM dyno information for the 235. Max net hp occurs at about 3600 rpm, max net torque at 2200. The line climbs at a steady rate until around 3200. I never had a tac on my stock 235's but my experience with the stock 3.90 rear end was it was happy up to about 60 (3000 rpm with stock tires per my calculator) much more then that and I would start pumping up the hydralic lifters. Remember these were designed before most places had roads with speeds over 45 mph.

[NEWFISHER]

With a 3:42 rear, 28" tall tire and a NWC T5 5 speed, my 235 is happy cruising at 65 mph

With the older rear end and the granny tranny, it hated 45 mph

[Michel]

Thank you very much OrrieG for the information's and chart. I was not expecting this engine to rev more than 3000. Mine as solid lifters.
I will use the truck only on secondary roads, so 45 is far enough for me.
I have made some calculation with my rear axle at 4.57 and 195R15 tyres, means that at 2000rpm, my speed will be at 35 mph and at 2500rpm willl be at 45 mph so it's ok for me.
I will check the real speed with my GPS on next time I will ride the truck.

NEWFISHER, at 65 I will not be so confident! At 30 I felt the truck was moving from side to side... my wife was not feeling so safe on sunday.

I need now to find a good way to set my ignition.

Thank you again for you help.

Michel from France

[Divine 59]

195R15 is a short tire. I use 235-75-15s on my 1/2 ton.

[OrrieG]

For a few years I had a granny 4 speed and 4.56 rearend in mine behind the six, but it spent a lot of time out in the boonies. I ran tall 16" tires to help, but the 45 mph you mentioned had it wound pretty tight. But it would climb a tree.

[Michel]

Divine 59, yes the 195R15 are small tires but this is the maximum size allowed for 15-6 wheels. I would use 235-75-15 but I need to find 15-8 wheels with 8 lugs and this is not easy here in France, not to say impossible.
OrrieG, 16' wheels and tires would help for speed, but too difficult to find. Buying in US is easy but transportation cost will be prohibitive for me.

[futameca]

Michel, thanks for asking this question, I've been curious about that for my truck. It's got the 270 engine with original rear end and am guessing that it would behave similarly. (?) 55 mph is about as much as I feel comfortable pushing it on the freeway.

[OrrieG]

Originally Posted by Michel

Divine 59, yes the 195R15 are small tires but this is the maximum size allowed for 15-6 wheels. I would use 235-75-15 but I need to find 15-8 wheels with 8 lugs and this is not easy here in France, not to say impossible.
OrrieG, 16' wheels and tires would help for speed, but too difficult to find. Buying in US is easy but transportation cost will be prohibitive for me.

Understand, I have shipped Ebay stuff to EU, Japan, Brazil, AU and South Africa, so I know about the costs for relatively small light items. Seems to me there is an opportunity for someone there to assemble loads for containers for big or heavy items assuming the buyers are not in a hurry. I know I sold some small parts to a guy in England that had me ship them to a broker in Seattle to put in the truck before it went in the container. He said he filled the cab and bed, then screwed plywood to the bed top so stuff would not "fall" out during transit. He even had aftermarket places shipping stuff there.

I am to lazy to do the research but remember that some Toyota, Jeep and other trucks will fit the six lug pattern, they might be more common there??

[Ratpin]

Originally Posted by Michel

Divine 59, yes the 195R15 are small tires but this is the maximum size allowed for 15-6 wheels. I would use 235-75-15 but I need to find 15-8 wheels with 8 lugs and this is not easy here in France, not to say impossible.
OrrieG, 16' wheels and tires would help for speed, but too difficult to find. Buying in US is easy but transportation cost will be prohibitive for me.

I've run 235/70/15 on a 15x6 for years and it's great. I've even run 225/75/15 on a 15x4.5wheel and no problems.

Is this just some weird French rule?

[Michel]

Not only a French but, but european one. We have the vehicle check every two year for new one and every 4 years for vintage ones.
If you arrive at the car technical control (MOT in UK), they check the compatibilty of the tire size vs rim size. The table says that a 15-6 rim is correct for a maximum 195R15 tyre.
I have replaced my rims by 16-7, the maximum tyre size acceptable is 225 width.

You are lucky in the US, you can replace an L6 engine by a V8, or replace the drum brakes with disc ones, even change the chassis by another one. This is completly forbiden in France or you must have the vehicule checked for NEW homologation which means gaz emision check, electromagnetic compliance, etc...impossible to get this new homologation as the vehicle must be as actual regulation. I know that some guy are doing such modifications but in case of damage on the road, they will lost the insurance of the car, and in case of death of somebody, they will have to pay all their life.

[wolffcub]

im on 235/55/r15 rubber and currently using a 3 speed with a 3.73 rear end. need to do 3200 rpm to get to 60mph. the 235 seems to handle it fine and its louder than hell. picked up a NWC T5 to install this spring. its a xxxx-146 model so it has the low 4.03 1st gear but i will live with it.

This is a good site to play with ratios and compare different setups and different rpm's

http://www.teammfactory.com/gear-calculator

[Race.it]

We get it a lot easier in the UK, we can change engines etc without needing the inspections

[Michel]

Originally Posted by Race.it

We get it a lot easier in the UK, we can change engines etc without needing the inspections

You are really leaving in a nice country

[OrrieG]

Michel , what about imported short term use??? Wife and I have thought about moving to an EU country for extended vacation (like one year Portugal or Ireland where we both have relatives) and bringing over one of the vintage cars to drive. Sounds like that would be more of a PITA than just buying a local car???

[Race.it]

Originally Posted by Michel

You are really leaving in a nice country

Not for long though if the eu gets its way

[Race.it]

Originally Posted by OrrieG

Michel , what about imported short term use??? Wife and I have thought about moving to an EU country for extended vacation (like one year Portugal or Ireland where we both have relatives) and bringing over one of the vintage cars to drive. Sounds like that would be more of a PITA than just buying a local car???

Depends on the country I know importing to Spain is an expensive and right pain to do, but they do tourist imports that are simpler you get a temp registration plate etc